I'm starting a new post because my older post is way too long by now. I'll try to quickly explain the problems and updates:

Problem 1: when I start the car, it will cough bad for a couple of seconds, then it will rev-up to about 2000 RPM and finally die. Usually this happens the first time, but then the second time it starts and it doesn't cough, and stays on. However, the colder the weather, the more difficult to start, sometimes it will do the coughing and reving-up thing a few times before finally staying on. I give it a few seconds between tries. This morning it wouldn't start at all, I tried like 20 times and it wouldn't stay on, and I had to take my wife's car. When I came back from work I tried again and it started the second time.

Problem 2: Especially the first few minutes until it reaches normal temperature, I may be driving at like 50 mph and it will cut off for a split second, during which all the lights in the dash come on (I have the dash with the horizontal speedometer, without RPM) and then it will resume. If the cruise control was on, it gets disabled by this "hickup" and even though the engine resumes power right away, I can't set the cruise again for about ten seconds. While this usually happens when it's cold, it also happened later in the day at temperatures of around 60 or 70, and after driving for several minutes.

Problem 3: Identical to Problem #2, except that the engine will shut off completely, I lose the hydraulic steering and I have to pull to the side of the road and restart it.

Now, I'm posting this message because going through the Chilton manual I saw the ports for the OBD1 and OBD2, and looking at mine I realized that it was OBD2, so I stopped at Advance Auto Parts and they read the codes for me. This is what it says:

History Code P0361 (for some reason this code doesn't appear on either the Chilton or the Haynes manual)
Ign System Problem
Elec Spark Timing
EST Not Toggling

And that's it. So the guy there told me that most likely the problem could be in one of these parts: Crankshaft Position Sensor, Ignition Module and maybe the Ignition Coil.

I wanted to post this here to get a second opinion on this, because I'm planning on replacing the sensor this weekend (since it will probably take me a while), but before I start spending my tax return on parts I would like to confirm that this guy was sending me on the right path more or less.

Things I already replaced since this problem started are: PCV valve, spark plugs Bosch Platinum 2 and Bosch wires, and Fuel Filter.

Also, if anybody could tell me what "EST not toggling" is, I'd appreciatte it.

Thanks for any replies.

Sebastian

Electronic spark timing, controlled by the ign module. If it won't start do you have spark, if you spray carb cleaner into the intake will it fire, I would start with these checks first. 0361 is an ign coil primary /secondary coil circuit malfunction. So you have 2 issues pointing toward the ign module, but you should do the prelimiinay checks first when it won't start.

P0361 = Ignition Coil K Primary/Secondary Circuit Malfunction


Basically, the crank sensor triggers the EST or (ICM), to fire the coils. If this signal is not consistent, you will get the P0361 code. This can also be described as "toggling" the EST.

Most of what you described is consistent with a dying crank sensor or ICM, except the "harder to start the colder it gets". That could be caused by the CTS (coolant temp sensor) which would tell the PCM the engine temp. When it gets cold enough, you have a "cold start enrichment" table in the PCM, that would add fuel just like the old choke. I have given instructions in previous post on how to check the operation of the CTS. Do a search and you should find it, if not post back and I will help.

P0361 = Ignition Coil K Primary/Secondary Circuit Malfunction


Basically, the crank sensor triggers the EST or (ICM), to fire the coils. If this signal is not consistent, you will get the P0361 code. This can also be described as "toggling" the EST.

Most of what you described is consistent with a dying crank sensor or ICM, except the "harder to start the colder it gets". That could be caused by the CTS (coolant temp sensor) which would tell the PCM the engine temp. When it gets cold enough, you have a "cold start enrichment" table in the PCM, that would add fuel just like the old choke. I have given instructions in previous post on how to check the operation of the CTS. Do a search and you should find it, if not post back and I will help.

Excellent, thanks for your reply. I will probably also replace the CTS since it's not very expensive. However, looking up the part in a place that sells AC Delco confused me (www.oehq.com), because there are two parts under that criteria, one is 213-77 and the description says "[Engine Cool Temperature Guage Sensor (w/Indicator Sw)] 2 Blade Terminal; Can Be Used As 1 Term Conn; Gauge (UB3)" and the second one is 213-928 with the description "[Engine Cool Temp Sensor] Interfaces w/ECM; 2-Way Male". If I have to guess I would say it's the second one because of what you mentioned about the ECM. Am I right?

One last question, do you think any of these problems could cause an excessive gas consumption? I used to get around 370 miles on a full tank on this vehicle, but lately I've noticed that I get around 260 at the most. At first I thought maybe it's because of the Bosch 2 spark plugs, thinking that because of the double spark they could be using more gas (sorry if this is a totally ignorant assumption which has nothing to do with the real thing), but the truth is that I hadn't been meassuring the gas consumption right before I put them, so I can't be sure it's because of them. I also saw another post from the Canadian guy with a reduced gas mileage problem in which you posted that the Oxygen sensor is the culprit for that. So do you think that in my case it may be the O2 sensor, or that these other problems I'm having also may have anything to do with the reduced mileage?

Thanks a bunch

I would replace the crank position sensor (CPS) first. They only cost about 30 bucks and usually when the ICM gives a problem, it is a total failure, not sporadic such as you have. 02's and clogged cats can degrade fuel mileage, however, I don't think plugs would make that much difference. (Even if they are Bosch)! The stalling part would not have any affect on mileage. The CTS could have an effect on mileage because, it could be stuck in a voltage range that would keep your engine from going into "closed loop" mode. Closed loop, means that the PCM is getting favorable feedback from all sensors, and has taken control of the engine while running. If the engine is in the "open loop" mode, it is a gas hog!

just fixed 95 lesabre doing same kind of things in my case after crankcase sensor,fuel relay, it was icm/pcm. (60.00 at salvage yard) but without reading all the post would never have gotten fixed. thank guys. have been running about a week.

Well, I changed the CTS (I decided to go for that first since I figured it would be easier than the crankshaft position sensor), and it's definitely not the culprit, because the car keeps doing exactly the same. Whatever is causing the problem, it's only getting worse because it used to be that I would turn it on, it would cough and shut down, and then at the second try it would stay on. If it was a very cold morning perhaps it would take 4 tries, but eventually it would start. This week, even before replacing the CTS, in a cold morning (around 25) it keeps coughing and turning off, I tried for like 15 minutes, with about ten seconds between tries, and it just wouldn't stay on. This happened two days in a row, and I had to take my wife's car to work.

I tried to replace the crankshaft position sensor yesterday, and when I had already taken off the wheel and protective cover to access the pulley, this guy that was passing by saw what I was doing and he told me that he had some experience with that, and that I would need an impact wrench to remove the bolt in the center, and a puller to bring out the pulley with the harmonic balancer because I wouldn't be able to do it by just pulling it out with my hands. I took my wife's car and ran to Advance Auto Parts and they told me pretty much the same, and they showed me a puller that I could use for that, and they have this tool loaner program for which you buy the tool and then return it, so basically I can get the puller for free. However, they don't do the same for the impact wrench, and I'm not going to buy one of those to use it just one time. I would have to try to rent one, but ideally I would like to do this sometime this weekend, and I don't know any rental places around here. So I went to Lowe's an bought this adapter that goes into a drilling machine on one side, and on the other side it has a 1/2 socket plug, so I can buy a 23mm socket for the pulley bolt. My question is, if HotZ28 or anybody knows, will I be able to do the job with a common cheap drilling machine and that adapter for the socket? Losening the bolt is not the big problem, what I fear is that probably when I put it back in it needs to be put back with an amount of force that the drilling machine wouldn't have. If that's the case, then I would have to wait and find a place that rents an impact wrench.

Thanks for any help

A drill will not develop enough torque for the job!! You can do it manually, or get the impact. Here is a couple of links that may help; http://www.automotiveforums.com/vbulletin/showthread.php?t=505203&highlight=harmonic+balancer
http://www.automotiveforums.com/vbulletin/showthread.php?t=384811&highlight=harmonic+balancer

A drill will not develop enough torque for the job!! You can do it manually, or get the impact.

When you say manually, do you mean just with a ratchet and the 23 mm socket for the bolt, and then just adjust it as hard as I can with my own strength, or are you talking about a specific tool to do it manually?

My main concern is, if I get the bolt out, and then get the balancer out with the puller, replace the sensor, and put the balancer back, if I tighten the bolt by hand, will that be tight enough, or is that not safe and I risk the bolt coming out after some time?

Also, do you have any opinion on the GP Sorensen line of products? Some AC-Delco products are not much more expensive, but in the case of the ignition module, the AC-Delco is $76 more expensive than the GP Sorensen, and that is a huge difference for me.

Thanks

To do this, you'll need to take the front right wheel off and remove the splash guard to gain access to the balancer. Removing the balancer bolt is a PITA unless you have the right tools. I use a C/P ¾ in drive impact wrench that develops over 500 ft. lbs. of torque @ 150 psig. It is easy with that! You might want to consider renting one at your local tool rental store; otherwise you will have to do it manually. If you choose the manual method, you need a deep-well six point impact socket, pull bar and a cheater bar. You will also need to have someone hold the flywheel with a large screwdriver wedged in the teeth to hold the crank from turning while you loosen the bolt. (You can also purchase or rent a flywheel holding tool). I have seen people remove the hood and stand on top of the engine with a six food cheater bar to break the bolt loose. Once the bolt is removed, the balancer will come off of the crank, with the aid of a balancer puller. Be sure to reinstall the bolt to the correct torque specs (150-200 ft lbs you need to verify). You will also need to use the screwdriver, vise grips, or other holding tool on the flywheel to keep the engine from turning while applying torque back to specs. Be sure to recheck the crank sensor gap when installed.


I would have the ignition control module & coils tested at AutoZone before replacing them. GP Sorensen control modules seem to work as well as AC Delco, however the crank sensor does not seem to be of the same quality. Be sure to check the warranty of both brands for comparison. The Delco crank sensor is about the same cost as the others, so there is no reason to use anything else!

To do this, you'll need to take the front right wheel off and remove the splash guard to gain access to the balancer.

Thanks again for your illustrative reply. Actually I did that the other day, that's when this guy came and told me I would not be able to unscrew the bolt without an impact wrench.

Removing the balancer bolt is a PITA unless you have the right tools. I use a C/P ¾ in drive impact wrench that develops over 500 ft. lbs. of torque @ 150 psig.

I called some places like United Rentals and checked with tool stores in this area but nobody seems to rent that. I saw this small impact wrench at Lowe's which sells for $30 and has a torque of 275 ft. lbs but it doesn't say anything about the psig.

http://www.lowes.com/lowes/lkn?action=productDetail&productId=220966-1126-IFT202&lpage=none

Do you think that would do the job? I would buy it if I don't have a choice, it's still cheaper than one hour of the mechanic's labor, but maybe I buy it and then it's useless and I wasted $30, so I would like your advice on this one if you don't mind.

If you choose the manual method, you need a deep-well six point impact socket, pull bar and a cheater bar. You will also need to have someone hold the flywheel with a large screwdriver wedged in the teeth to hold the crank from turning while you loosen the bolt. (You can also purchase or rent a flywheel holding tool). I have seen people remove the hood and stand on top of the engine with a six food cheater bar to break the bolt loose. Once the bolt is removed, the balancer will come off of the crank, with the aid of a balancer puller. Be sure to reinstall the bolt to the correct torque specs (150-200 ft lbs you need to verify).

How do I verify the torque? Do I need some expensive tool for that?

You will also need to use the screwdriver, vise grips, or other holding tool on the flywheel to keep the engine from turning while applying torque back to specs. Be sure to recheck the crank sensor gap when installed.I would have the ignition control module & coils tested at AutoZone before replacing them. GP Sorensen control modules seem to work as well as AC Delco, however the crank sensor does not seem to be of the same quality. Be sure to check the warranty of both brands for comparison. The Delco crank sensor is about the same cost as the others, so there is no reason to use anything else!

Yes, actually I already bought the AC-Delco crank sensor because it was only 6 dollars more expensive, as well as the oxygen sensor because of my reduced gas mileage, which I still haven't changed. The coontrol module is another story however, being the AC-Delco $76 more expensive.

Thanks a lot

Don't worry about replying to the last two questions, I went to Lowe's and I realized that the $30 impact wrench is a air tool, and no way I'm going to buy an air compressor just for this. The people at the Advance Auto Parts told me that I could use a torque wrench for that, but they are pretty expensive too, so I'm trying to decide what to do.

Thanks

I found a decent torque wrench at Harbor Frieght Tools for only 12 bucks! It's not a known brand, but it gets the job done.

Again, you should test your ignition control module and coils first, then change the crank sensor if they test OK. Take the whole unit to AutoZone for testing.


Get several quotes from shops in your area to install just the crank sensor. It should not take more that 1-hour. (50-80 bucks). Add up the cost of the tools you will need, and then do the math. Your labor is free, however your experience is limited, and if a shop did install the CPS, it should be done right, or they will have to make it right!

Again, you should test your ignition control module and coils first, then change the crank sensor if they test OK. Take the whole unit to AutoZone for testing.

I will do that actually, but today it's been raining all day long here so I haven't had a chance to do it. However, correct me if I'm wrong, but since the car is very close to the 100,000 miles, wouldn't it be a good idea to replace the crank sensor anyway, just as maintainance? I mean, it's $36, and if I replace it I know it'll work perfect because it's brand new.

Get several quotes from shops in your area to install just the crank sensor. It should not take more that 1-hour. (50-80 bucks). Add up the cost of the tools you will need, and then do the math. Your labor is free, however your experience is limited, and if a shop did install the CPS, it should be done right, or they will have to make it right!

Well, you have a good point there, however, on one hand I'm really stubborn and I like to follow things as far as I can to learn something new, and also I like to fix things myself. I don't like to depend on a neighborhood mechanic or a dealership that will charge me $75 an hour just to tell me what the problem is. I'd rather take more time, investigate, and see if I can do it myself. Of course I wouldn't dare doing major mechanical stuff like rebuilding the transmission, but changing this sensor is something that doesn't really seem that impossible to me. I mean, after I manage to get that pulley/balancer off, and take another cover, the sensor is there, I take the old one and put the new one in. It will take me a long while, but at the end I will have the satisfaction of fixing my own car rather than depending on somebody else to do it. That means a lot to me. Of course there's also the issue of not having almost any extra money because I don't make a lot, so wherever and whenever I can save a buck I will.

Thanks

However, correct me if I'm wrong, but since the car is very close to the 100,000 miles, wouldn't it be a good idea to replace the crank sensor anyway, just as maintainance? I mean, it's $36, and if I replace it I know it'll work perfect because it's brand new.
You are right on the above. If you have 100K on the car, it is just a matter of time until it fails completly.

It will take me a long while, but at the end I will have the satisfaction of fixing my own car rather than depending on somebody else to do it. That means a lot to me. Of course there's also the issue of not having almost any extra money because I don't make a lot, so wherever and whenever I can save a buck I will. :grinyes:
Yea, I know the feeling of doing the work myself, at least I know it is done right and I also get that personal satisfaction when the job is complete. Sometimes when things don't go well, remember that someone else may be having a worse day than you, like the lady below;

A psychology student in New York, rented out her spare room to a carpenter, in order to nag him constantly and study his reactions. After weeks of needling him, he snapped, and beat her repeatedly with an ax, leaving her mentally retarded.
:twak:

If you have a Harbor Freight nearby, you can find what you need to do the job and save some big bucks. You can also order online. Here are two of the items, you may need.


http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=37824
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=30395
:cheers:

Seems I'm out of luck with that damn bolt in the crankshaft pulley. I tried today with a breaker bar, and I only managed to deform the 3 slots on the front (I had part of a wrench holding it so it wouldn't rotate along with the bolt) , but the bolt wouldn't come out. I really would like to try with an impact wrench, but I still have to find a place here that rents one. I did however take the module and the coils out, and they tested the module at the Autozone and according to their machine it's working fine, but they told me they had no way of testing the coils (seemed weird to me), but this other guy at Advance Auto Parts told me that they could be tested with a voltage tester, so I got one at Walmart and the guy helped me do it. According to him they are working just fine. So that's two things that I can discard as the problem. I will keep trying to find an impact wrench for the next few days before giving up and taking the car to the mechanic. I would feel pretty stupid if I take it now and the guy tells me that the main problem was the crankshaft position sensor.

Funny thing, when I assembled everything back into place, the coils and module, and the belt, I turned the car on and it cranked right up and stayed on, even though it was in the upper 30s here today. After that I put the protective cover and the wheel back on, tried again, and again it cranked right up perfectly. An hour later my wife was coming from the street and I asked her to try and she told me it cranked right up. I'm beginning to think this damn car has a mind of its own. I wish it were like Christine, it would be evil but at least it would fix itself ;)

Sorry to here about the balancer bolt, that is why I refer to it as a PITA!

You may have got lucky removing the ICM connector and then reconnecting it. Your crank sensor wiring goes through that connector to the ICM and if it is not clean and making good contact, bam, all kind of ignition related problems arise. If it continues to start & run, remove the connector again and clean it with contact cleaner and check for any loose pins or cracked wires.

Just to give you some additional information on how the DIS works, I will start from the initial starting sequence and take you through the PCM control.

When the engine is starting, and for 8 seconds after starting, it is running on the ignition control module, then the engine control is then passed on to the PCM. When the PCM takes control, the engine remains in "open loop", until favorable feedback is coming from all sensors. Once the feedback is favorable, the PCM will go to "closed loop" and maintain engine control. If any of the sensors fail to maintain favorable feedback, the controls go back to "open loop".

One of the more critical functions of the ICM, is the electronic spark timing function. The EST function controls the engine timing advance and retard. Of course, we all know that in order to have reliable starting functions, the timing has to be accurate. The other function of the ICM, is to turn off the current to the coil. When the CPS signal is made, the module turns the current back on. It has to be extremely accurate in when it does this. One advantage of an electronic ignition system is it will produce higher voltages, up to twice the voltage a conventional system can produce. This is why good wires and plugs are critical to help keep voltage from jumping to ground.

As someone who has done this on at least two different cars, one of which is my 92 Lesabre, I can say that in this case you should pay someone to do this. Yes, it will cost a lot but it is difficult to do properly primarily because of the very small clearance between the sensor and the fins of the harmonic balancer. Without a clearance tool or experience, it would be very easy to botch this job and cause you to have to pay someone in the end anyhow. The space is so small where the fins go through that aligning it by hand is extremely difficult, especially considering that the fins will move slightly as you tighten the pulley down, thus slightly messing up your adjustment up to that point (and not to mention that there is a plastic piece that blocks your view and adjustment of the sensor once you are putting the pulley on for good.) Also, if you buy an off-brand sensor, the metal on the piece that holds the sensor is often so cheap that it will break in two as you tighten the bolt that locks the sensor in place after it is properly adjusted.

Do yourself a favor and pay a good mechanic to put the crank sensor on and also to properly diagnose your other problems (then you can decline repairs and buy and replace the parts yourself).

"....but at the end I will have the satisfaction of fixing my own car rather than depending on somebody else to do it. That means a lot to me."

I'll drink to that!

You may have got lucky removing the ICM connector and then reconnecting it. Your crank sensor wiring goes through that connector to the ICM and if it is not clean and making good contact, bam, all kind of ignition related problems arise. If it continues to start & run, remove the connector again and clean it with contact cleaner and check for any loose pins or cracked wires.

Most likely it was that, because I went out there twice again, three hours ago, and then 30 minutes ago, and it started like a charm, like it was a new car. As soon as I turn the key not even half a second and the engine is running. Besides the ICM connector, perhaps it could also have been the ICM to coil connectors, since the ICM was filthy with carbon and get this, there was even a dead fly in it that I could see once I removed one of the coils. Beats me how it got there, but I cleaned the ICM with some alcohol (not too much thought, just cotton balls with a bit of it), and especially cleaned the six connectors where the coils go. Whatever was causing it, both the cleaning and the connecting back in place seems to have taken care of the problem. I wish I would've tried that since the beginning instead of going for the crank sensor. I would've saved some money in sockets and whatnot. Thinking about it, it kind of makes sense how the car could not start in cold weather but it was easier when it got warmer later in the day. At least here in Raleigh we've been having a really strange winter, it still hasn't snowed for real, and it was normal for the past couple months that the nights and early mornings would be in the upper 20s or low 30s, and then it went up to like 70 after noon. Given that metal expands a bit the warmer it gets, if two piece of metal were barely touching because of a connector that wasn't tight enough, the colder those two metals were the less they were touching each other, if at all. The warmer it got, the two metals expanded, not something visible to the eye, but probably expanded enough to touch the other, and that's how the car was able to start. However, being the connectors not tight enough, the movement of the car itself could create a false contact between those metals and thus the surges I was getting sometimes, or the car cutting off completely.

Of course this is all wishful thinking. It's suposed to snow for real for the first time this winter here, and tomorrow morning it will be really cold. So let's see what happens tomorrow morning.

Now, if my brakes problem would be solved just by taking away the master cylinder and the booster and then putting them back in place, I would be sooo happy :)

I read your explanation about the whole process, and it's very interesting, but it leads me to another question. How do I know for sure that the car is working in closed loop, and not in open loop? Because it's insane that it used to give me 360 miles on a full tank and now it's 260. It doesn't make sense at all. I still haven't changed the oxygen sensor, which I have here, and I probably will change soon, but how do I know for sure? If I have the Autozone guys read the codes, and it doesn't show anything, does it mean for sure that it's working in closed loop mode?

Thanks

I read your explanation about the whole process, and it's very interesting, but it leads me to another question. How do I know for sure that the car is working in closed loop, and not in open loop? Because it's insane that it used to give me 360 miles on a full tank and now it's 260. It doesn't make sense at all. I still haven't changed the oxygen sensor, which I have here, and I probably will change soon, but how do I know for sure? If I have the Autozone guys read the codes, and it doesn't show anything, does it mean for sure that it's working in closed loop mode?
Thanks

Drive the car back to the AutoZone where they checked the codes, and if they are using a full function scanner, it will tell if it is in closed loop or open. Be sure the engine is up to full operating temp before doing this.

Well, it seems I spoke too soon. This morning it went back to coughing and dying like an old cancerous man. It was 32 outside, which was the same temperature when I went for a drive last night. This time it stayed on at the second try, however after driving it a few feet it surged and then stalled. I turned it back on and backtracked to the spot where it was and took my wife's car. So I guess I'll be taking it to the mechanic. Don't get me wrong, if I was positive that the problem is the crank sensor, I would actually buy an impact wrench for that damn bolt and do it myself, but what if it's not, and I end up wasting like $100 in a tool that I will probably never use again?

My fear is that the mechanic will also have a hard time trying to find what the problem is, since it's so bizarre. I mean, last night after I mounted back the ICM and coils, and plugged the connector back in, it worked fantastically. It was 32 degrees, and yet it would crank right up. But then this morning, same temperature, and it began doing the same thing again.
So how will he be sure that he fixed it, other than replacing all the ignition parts one by one, and charging me a lot of money for it? But well, right now, I have to make a decision, either I keep wasting money in components and tools playing a guessing game, or I take it to a professional, and I think I'll have to do that.

Again, you should test your ignition control module and coils first, then change the crank sensor if they test OK. Take the whole unit to AutoZone for testing.
Your ICM may be grounding out due to a crack in the housing and mositure saturation! The link below FYI.
http://www.automotiveforums.com/vbulletin/showthread.php?t=513963
:uhoh:

Your ICM may be grounding out due to a crack in the housing and mositure saturation! The link below FYI.
http://www.automotiveforums.com/vbulletin/showthread.php?t=513963
:uhoh:

I took out the ICM and I didn't see any cracks in it. Plus, they connected it to that big tester at the Autozone and it came out fine.

I checked that other thread you mentioned, but his symptoms are really not similar to mine. But thanks anyway.

Another device that measures temperature is the intake air temp sensor. Your car may have one and should be somewhere in the air delivery system to the engine.

I came to realize over time and especially today that the problem of the engine surging and sometimes cutting off while driving is related to the humidity in the air. I began realizing this before, but today is a bit humid here in Raleigh, and the damn car cut off on me like 5 times in about 20 miles, even after reaching normal temperature. And I this happened before, on humid days the car will cut off a lot more. And today it's only mildly humid, it's not like Ohio or Florida. However it wasn't that hard to start the car. So each problem became worse or better depending on the temperature, the starting problem gets worse the colder it is, and the surging problem becomes worse as the air gets more humid. Damn car.

If I took a guess I would say there's a condensation problem somewhere. HotZ28 mentioned it could be a crack and moisture in the ignition module, but it that were the case, would it pass the test they do at the Autozone?

But well, as of now I'm just waiting for my tax return to take it to the mechanic, I'm not going to try to guess anymore because I may end up spending a lot of money and not get to the problem, while the mechanic has over 20 years of experience and he can probably tell what's wrong just by looking at it.