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Odd behavior and trouble codes - Need a fresh perspective

12-15-2009, 07:06 PM
kk, I have posted a few things here tonight, but I will put as much info as I can here in my own thread.

1. Car wont pass vehicle emissions testing HC slightly high, C0 over double limit
2. Idle high, had to turn idle screw all the way to the bottom, still a little high (started a few years ago)
3. idle drifting, a little high for a minute, then almost stalling (sometime does stall)
4. code 15 (or 51?) What is the standard for reading obd I
5. Engine missing under load (usually uphill) only at OP temp. Very low power
6. mysterious coolant loss, very slowly
7. the coolant fan only runs when the key is in the run position

Now for background info. 94 metro 1.0L TBI (VIN 6) automatic (not XFI). Replaced engine with JDM longblock 33k ago.

Water pump replaced 25k ago
timing belt replace 22k ago
starter replaced 10k ago
trans, oil, coolant serviced this month
replaced second half of exaust system, but not a new cat (it has two) this month
replaced plugs
replace wires couple years ago
replaced air, fuel filer this summer
Alot of little work I cant think of at the moment...

The high idle started a few years ago, couldnt figure out the problem, so I just cranked down the throttle, but it still idled a little high.

Dont know if this is related, but the check engine light flickers constantly when warm. After reading about the EGR failures a few years ago, I started checking/cleaning that system every 6 months. I checked it today, and it seems to be working fine. Diaphram actuator holds vacumme, valve actuates. Havent cleaned the port since this spring though.

Another thing to note, I recently put in stop leak (hate that crap), and noticed later a dribble out the top front where the plastic housing meets the cooling fins. I assumed I had a small leak there (since its plastic), but I have since seen small coolant loss, same as before.

I know I probably have several problems here, I have checked all the coolant sensors, and replaced a few except the air charge sensor.

Also recently I noticed my wires crossfiring at night. rev the engine and watch the pretty blue lights! :P I have tried to seperate them, but they are only about 2 years old. I put about 11k on my car a year they shouldnt go bad that quick should they? That could explain my uphill power loss. But I might have bas connections aswell.

Last but not least, I read on here a guy saying he had read the trouble code wrong that 15 was 51 because after the 5 second timeout the light blinks once to start the reading. If you count that blink you would get 1 then 5, if you didnt count that first blink you would get 5 then 1. Now I never heard of not counting that first blink but on this site troublecodes.net under the BMW it DOES say there is an initial blink then the codes start. Could someone set me straight on this for once and all. I know this isnt a BMW :P

Tomorrow I think I might run a compression test. Anyone know the correct compression for a good cyl? I know these arnt high compression so I'm guessin around 100 for worn engine. Also My engine should have less than 100k. Actually 66-83k (on the longblock) (JDM import)

thanks guy, I see there are some experienced tech on here, and I'm no wipper snapper myself, so no baby talk plz :)

Thanks for the help


12-15-2009, 07:13 PM
Thought I would add that the crossfire missing, is obvious (intermittent), where as the low power uphill seems to be constant, and a recent development. Also no signs of water in oil -- oil in water. both seem to only happen when engine is warm.

12-15-2009, 07:26 PM
Your sucking air. High idle usually indicates vacuum leak. Could be a broken hose, a disconnected hose, or an intake manifold gasket or seal. Spray either
or carb cleaner around gaskets, seals or hose connections. Or you can use an unlit propane torch. If theres a leak you will see a change in rpms. If you have an idle motor it could be malfunctioning. Hope this helps.

12-15-2009, 08:15 PM
intersting, hadnt thought of that test for the high idle. That particular problem started a few yearsa ago, and I poured over the systems but couldnt find the problem, hoses among many other things were inspected at that time. My result was that there was an idle up AND an idle down solonoid, and that one was bad. (much later) After further analysis I can find no such devices on this vehicle.

Funny note when I checked the egr system today I found the tell-tale 1/8 in split where the EGR vacumme actuator diaphram line goes into the TBI, grinned with anticipation as I trimmed it off, but no love :( didnt seem to change a thing.

I will however take my torch out there tomorrow and see if I can detect a vacumme leak. Now that you mention it, I noticed another line that looked aged. Not cracked, but you know...

anyway thanks for the reply. this is exactly what I need, a fresh perspective. I guess when you have been doing this so many years you forget to check the simple stuff :P

thanks :)

12-16-2009, 06:59 AM
Idle control motors go bad on these engines, also a maladjusted TPS can cause a high idle.

Coolant fan is not supposed to run with the key off, despite the warning sticker near the radiator.

12-16-2009, 05:38 PM
Thanks for the replies. I appreciate the help.

Where the heck would the idle control motor be? I checked the TPS for correct operation last year. This particular problem has been going on for several years. What I read (several years ago) refrenced an 'idle up' and an 'idle down' solonoid. I was alot less familiar with the engine at that time. I was real busy when I put the long block in, so I was more concerned that everything was connected properly rather than what its actual function was.

Vacumme test was negative for leaks using the torch. tomorrow I plan to inspect each vacumme end for splits visually.

I think I just figured out where the idle control motor is. mounted center firewall, two wire electrical, vacumme in, vacumme out? I always wondered what that did. Thought it was the A/C idle control. even though it connects to the breather housing. I have known for awhile that didnt work, or at least I suspected it didnt. I can grab one of those at the local pull yard for a few dollars. I have a few other things to pick up there aswell.

Compression test results:

Cyl #3 - 140 dry - 140 wet
Cyl #2 - 140 dry - 140 wet
Cyl #1 - 135 dry - 138 wet

Keep in mind my equipment. I can tighten down the spark plug adapter with a socket, but the hose has a brass fitting, and because of the recessed holes I had to get on the end of the brass fitting (not the part with the hex drive, the crimp area) with a pair of wire pliers. It has a tapered fitting, so the seal should be relativly good, but I didnt want to crank down on it for obvious reasons.

Any more ideas to the above mentioned problems?

12-16-2009, 06:46 PM
Did you have the throttle wide open?

I like the compression testers that seal with o-rings between the head and between the adapter. Easy to get a leak free seal just twisting the hose by hand.

12-16-2009, 06:51 PM
Did you have the throttle wide open?

I like the compression testers that seal with o-rings between the head and between the adapter. Easy to get a leak free seal just twisting the hose by hand.

Damn I hate mistakes. no I didnt do the tests at WOT. how would this affect my tests?


rotate faster giving higher compression? if thats it, I'm more worried about consistancy between cylinders to know if I have burnt valve, or warpedhead/bad gasket.

12-16-2009, 06:55 PM
Aha. Usually the numbers are about 30 psi lower if the throttle isn't held open. 170 sounds more respectable than 140.

Yes, I agree the main thing to look for is that they're even.

12-16-2009, 06:59 PM
cool, thanks for the info. Got so much going on, and I had read that awhile back, but these days I just seem to make more an more mistakes :P

BTW I thought these werew low compression engines, my manual only recommends 87 octane.....

12-16-2009, 07:09 PM
wow, just read on another thread that you do comp test with all plugs out. I wondered why you were getting so high reading on these engines. For the recored I have never done comp test like that. Not to say I'm right, but we have always done comp and leakdown tests just by pulling the plug and connecting the adapter.

Who says you cant teach an old dog.....

12-16-2009, 07:45 PM
Yep, pulling all the plugs should let is spin as fast as it can. And if the factory gives a spec as to what compression should be when new, then you can compare.

Pulling one plug at a time will still show any cylinder that's lower than the others, which is mainly what you're looking for. For a leak-down test it obviously doesn't matter.

Compression test should also be done after the engine's warmed up. I don't like pulling plugs out of an aluminum head when hot though (plug could take threads out with it), so I usually let it cool off a bit.

Compression ratio for the G10 is 9.5:1. Must be well-designed to still use 87 octane.

12-16-2009, 09:26 PM
Well since CAD most cars are well designed. Most problems I think come from poor thought process ie. 'we have have 11mm clearance we can put a bolt head in there that takes 9mm' but dont think that the bolt thread is 19mm, and you have to unbolt the engine mount and jack up one side of the engine to remove the bolt etc etc cause they put the bolt in while the engine wasnt in the vehicle. Most of that has past and havent seen real problems like that since the mid 90's. but they probably still exist.

man dont even start with the aluminum heads.... Us rednecks had alot of problems since we were used to cast iron. I still have a good tap, and helicoils in my box. I have stripped many in the past. I think the advent of good anti-seize has prevented alot of that, as I havent retapped a plug hole in years. I dont go for those packets either, they cost ten times as much. a good $8 tube lasts a really long time.

9.5 isnt hight comp, at least as far as I know. The owners manual recommends 87, and thats inline with low comp.

remember octane is gasolines 'resistivity' to burn

thanks for the insight on the comp test ;)

12-18-2009, 12:34 AM
Well, I found I DID have some vacumme leaks. I was determined to find this 'idle control motor'. I found multiple cracked/dried vacumme lines. I had replaced about half of them a few years back, and the propane torch test didnt seem to yield anything. I used to use WD-40, but it doesnt burn anymore. Yep thats right. Formula WD-40 isnt the same as your dads WD-40. I have known this for a few good years, as I used to use this (as taught to me by my father) as starting fluid for 2 cycle engines. This is better for them because they dont oil like 4 stroke. About 5 years ago I grabbed some WD and noticed it didnt behave the same way, so I tried to burn it and noticed it didnt burn anymore!!! Sorry, I digress...

I suspect the leaks were so bad the propane wouldnt make any change. Anyway, I pulled the solenoid valve from the middle top firewall, and tore it down. I still dont know what it does. It has a vacumme loop to the air filter. There is no vacumme from the in line, but I notice when I blow through the return the idle drops!! I suspect a bad seal on the TBI to breather assembly as welll as bad vac lines.

I also saw another solenoid mounted to the back of the throttle body. I had forgotten about it since I put the engine in it. Like I said, I never paid much attention to specifics, just that everything was replaced proper. BTW the engine ran great after the long block swap. Anyway, I pulled that aswell, and here is what I found.

The solenoid mounted top center firewall was clean. I tore it all the way down. It has a fatty coil that registers 27 ohm. Looked so good I didnt even bother to lube the spring, though in retrospect a little lithium grease couldnt have hurt.

The rear TBI mounted solenoid loops the TBI, and had a seperator of sorts on it. Looks like a fuel filter. Tubular, 2 in dia, 3 in height. One port out of the side on the top and bottom. Asummed it was a filter at first. After I pulled the solenoid down it was filled with engine oil. Now this coil was sealed, and kraike, I forgot to test it, but it uses a spriral spring sloenoid valve. very interesting, I have rarely seen such a design. Anyway clean the crud, and mechanical operation and seals looked solid. I think the 'filter' is not a filter at all, but is empty is to keep crap from flowing up into the solenoid valve (like an air lock on a wine vat). I would have thought that such an item would have a harness to identify its correct position. nawwww. Anyway, I aparently installed it upside down, and allowed crap to flow INTO the valve. Seems no worse for the wear, but explains how the stuff got in there.

Somehow I was leery testing the electrical directly because I was hooking up a dimmer switch last night to limit current on a bench grinder, and got confused (ok maybe drunk :) but that damn black, red, blue confused me with house wiring black (hot) white neutral :P So I wasnt in a hurry to fry these in case they need current limiting. Furthermore I wasn under the impression they were motors (air pumps?), but they are just air valve solenoid operated. They should last a billion years!

Anyhow to finish my novel here. I didnt test the one coil, and I didnt test any voltage from the wiring. Good god I asumme its working ?!?! I did however pick up 15 ft of vacumme line, and I intend on installing it tomorrow. I hope it will solve some problems. Though I must say at least one of those valves wouldnt have worked new hose or not.

I'll post back with a sequel in the metro saga!!

Thanks guys

08-22-2010, 07:15 PM
Did you find cause of your problems?

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