Diagnosed by schucks, wasted $300. Can you help?

[jeremywitt]

1995 S10 Blazer; 4.3L Vortec
Purchased used 1 year ago w/135,000 miles
Now @ 150,000 miles

Problems:
Shaking very hard
Barely makes it up hills with it floored
Oil gauge on dashboard is dropping then coming back up
When I started it this morning it died after only two seconds of running. I fired again and it stayed on but running rough.

I was having more problems such as: (these problems are fixed)
Popping sound near engine (schucks diagnosed as bad spark plug wire)
Electrical gauge dropping and coming back up.
Loss of power overnight. (I think my remote wire to my amp is screwed)

plus problems above...

So I went to schucks to have them do an OBD test on my truck. Somehow my truck has an OBDII Plug on it. The check engine light was on when I went there yet when they hooked up to it and turned the key the light went off.
This same thing happened 3 separate times that I've been there.
So while this guy is testing my battery to see why i'm losing power he says "That popping sound is a bad spark plug wire" so I started telling him about the loss of power and not being able to go up hills. He was sure that it was the wire. So I purchased a new battery , the wires and he insisted on the plugs as well. So the total was $140.

It turns out that I could not change the spark plugs or wires myself and so I paid a (supposedly reputable) mechanic to do it at his house. When I returned to pick up my truck and gave him $150 for the job, the power loss was still there and its still shaking, only now it backfires too...

I feel like I'm driving a piece of crap and I seriously need some advice. Please help, I'm suppose to go see this mechanic again tonight so he can test my fuel pump but I don't know him that well and I'm not sure if he is just trying to get me to spend more money.

[Mav06]

Could it be that you have no compression in a cylinder meaning bad rings or a valve isn't closing all the way that could be your loss of power and shaking.
What about your distributer cap and roter have you looked at those?

Just a couple thoughts
Matthew

[blazee]

I would take a look at the fuel pressure regulator and/or "nut kit" (the fuel lines in the plenum). They are known to leak and cause the problems that you describe. This condition also causes the engine to waste a lot of fuel, which can also cause problems in the EGR system. The fluctuating volts and oil gauge could be a result of the RPMs dropping when the engine misses. There's info about the FPR and nut kit as well as how to check them in these threads:

http://www.automotiveforums.com/vbul...d.php?t=462726

http://www.automotiveforums.com/vbul...d.php?t=473110




I would find a different mechanic, you got ripped off. Changing the plugs and wires (the distributor cap and rotor should have been changed at the same time) is only a 30 minute job and fairly simple. The plugs can be accessed through the wheel wells. There is only one plug that is difficult and you can see the procedure to change it here:

http://www.automotiveforums.com/vbul...d.php?t=503231


If you have a later model 95 with the horizontal distributor cap, the number 1 and number 3 plug wires are easy to get confused. The "mechanic" may have gotten them wrong, they are the only wires in reverse order.

[jeremywitt]

Thanks for the info. I've read both threads and am still confused, do i need to get a new fuel injector? or just change the "nut kit" and FPR?

I spoke with that mechanic again and he wants me to purchase a fuel injector which is like $389 vs. the $89 "nut kit".

It is christmas time and I have alittle extra money but it won't make for a fun christmas at my house.

[blazee]

You'll want to check to make sure one or both of them are leaking before buying anything. You can pull the vortec cover and the IMT valve to try peeking through to see if they're leaking, but it's better to pull the upper plenum so that you can get the full view. The whole inside should be black, if it is leaking there will be clean spots from the fuel washing the inside. Clean spots on the driver side indicate a leaking nut kit. Clean spots on the passenger side indicate a leaking FPR. If one of them are leaking you can replace just the one that's leaking, but a lot of people just replace both so that thay don't have to worry about it. A leaking FPR used to mean that you had to replace the whole fuel injector, but now you can buy and replace just the FPR, as shown in this thread:


http://www.automotiveforums.com/vbul...d.php?t=503238


Again, before replacing anything, you need to check to see if they're leaking. This is one of those things that is very common and easy to check for, that's why I recommend starting here. The problem could be something else entirely, so check it out first, you don't want to waste anymore money.


Another thing that you can check for is carbon chunks in the EGR valve. If you find them, the valve can be cleaned and doesn't need to be replaced.

[jeremywitt]

So, I've planned for Saturday morning to pull the upper plenum off to check for leaks. I'm also going to replace the distributer cap and rotor while in there since they should be easily accessible with the plenum off.

Note: I've found the electrical problem (hopefully the only one) that was draining my battery overnight. The button that turns off the light inside the glove box is broken and was not turning off the light. I did a quick tape job and the light is off now.

Note: This morning when I was driving to work the truck ran almost normal (still running rough, but no strong shaking) for about 3 minutes, then started shaking and backfiring again.

You've given easy descriptions for how to tell if the FDR or "nut kit" needs replaced... How can I tell if I need to replace the injector?
The reason I ask is because I don't want to purchase the FDR &/or "nut kit" then find out that the injector needs replaced also. (i think the injector comes with both FDR & "nut kit"?)

So the mechanic that I went to originally is going to help me do all this, at my house, for free (or consider it part of the $150 I gave him for the plugs n wires changeout) I showed him the information that you gave me and he was actually glad that I did some research and consulted with some experts on the net. He didn't know that you could purchase the FDR seperately and didn't know what a "nut kit" was but I showed him the info on both.
So there was a schucks right next door, we went over to see if they had the FDR in stock (to see cost)... and they don't. I know in the other thread it said you could purchase it in alot of places. Where should I start my search?

Also, he checked the plug wires and had his coworker check them too and both agreed that they were in correctly. They hooked up a computer and it said that "Number 2" was misfiring?? any thoughts?

One more thing, what is the EGR valve? How do I check it?

Thanks in advance!

[maxwedge]

Napa/Dorman has the nut/regulator kit.

[jeremywitt]

Awsome, I live in Seattle so theres got to be one nearby.
Thanks!

[jeremywitt]

So the mechanic never showed up and didn't answer his phone. Punk!
What do I need to do to remove the upper plenum myself?? I have limited tools... ie screwdrivers, socket sets, pliers.
Basically what i'm looking for is a step by step of how to do this. Have you seen one?

[DelCoch]

Originally Posted by jeremywitt

. . . What do I need to do to remove the upper plenum myself?? I have limited tools... ie screwdrivers, socket sets, pliers.
Basically what i'm looking for is a step by step of how to do this. Have you seen one?

Check these links out - should answer your question.

http://www.automotiveforums.com/vbul...d.php?t=503238

http://www.automotiveforums.com/vbul...d.php?t=473110

http://www.automotiveforums.com/vbul...d.php?t=486234

http://www.automotiveforums.com/vbul...d.php?t=559014

[rlith]

With the #2 plug misfiring and the fact that you change all the plugs/wires out, I would say overall you have a faulty CPI unit, not just the pressure regulator. What is probably happening is that the poppet going into the #2 cylinder is probably faulty at this point. Replacing the CPI and most likely the nut kit is your best course of action. When you pull the upper plenum you will probably see washing on both sides. You should also do a pressure test at the shrader valve. This goes a long way in the diagnosis.

[jeremywitt]

Originally Posted by rlith

With the #2 plug misfiring and the fact that you change all the plugs/wires out, I would say overall you have a faulty CPI unit, not just the pressure regulator..

ok... should I still pull the upper plenum to check or not?

Originally Posted by rlith

What is probably happening is that the poppet going into the #2 cylinder is probably faulty at this point. Replacing the CPI and most likely the nut kit is your best course of action..

doesn't the CPI come with the "nut kit"??

Originally Posted by rlith

When you pull the upper plenum you will probably see washing on both sides. You should also do a pressure test at the shrader valve. This goes a long way in the diagnosis.

What is the shrader valve? How can i do a test on it?

[jeremywitt]

So what I am planning on doing is going to my parents house where I can get help if I need it.. ie. money/extra hands.
I'm gonna try to replace everything.... CPI, FPR, "nut kit", distributor cap & rotor. (plugs & wires already done) Hopefully this will get rid of the problem.

Can I purchase the following all together??

eBay - $225 (this is the CPI... right?)
http://cgi.ebay.com/ebaymotors/92-95...QQcmdZViewItem

eBay - $38 (FPR)
http://cgi.ebay.com/ebaymotors/CHEVR...QQcmdZViewItem

RockAuto - $48 (nut kit)
http://www.rockauto.com/catalog/cata...FR321-17112705

Anyone know of better deals?

[rlith]

Originally Posted by jeremywitt

ok... should I still pull the upper plenum to check or not?

Yes, check for washing. Passenger side indicates CPI leak, Driver's side washing shows Nut kit leak

Originally Posted by jeremywitt

doesn't the CPI come with the "nut kit"??

No, seperate items. Though if it is only the pressure regulator, see my how-to for part numbers for replacing that instead of the whole CPI. (That is if the main CPI unit is ok)

Originally Posted by jeremywitt

What is the shrader valve? How can i do a test on it?

The shrader valve is a test valve in back of the plenum (looks like a fat bycicle valve). You would hook a pressure gauge to it.

Turn the key to the run position (do not start the engine). Pressure should go to 56-61 PSI. Turn the key to the off position. If the gauge drops faster than 1 pound per 5 miniute period, that shows that you have a leak in the system.

[jeremywitt]

Ok, so I'm at my parents house now and I've spent the entire day working on my blazer. I used the instructions that I was directed to earlier in the post to pull off the upper plenum, noticed the entire FPR side was clean and what looks like a small leak on the other. I replaced the distributor cap and rotor also.



I went to NAPA for the third time in the day and got the FPR hoping that maybe it would "fix" the problem. I pulled the old one pretty easily and had a hard time putting in the new one. But I finally got it in minus the little o-ring that was around the open end. (The one that I pulled out didn't have an o-ring on it either.) I tightened that thing up, cleaned the gasket gunk off the plenum surface and put on the new gasket. Then put everything back on in the reverse order that I took it off. I tried to start it and it didn't start on the first try, then it started and ran REALLY rough for only a few seconds and died. I tried it a couple more times and the same thing happened. I took a break to eat and realized that I forgot to put on the vacuum hose on the back near the dist. cap.

So I put that on, rechecked that everything was connected and tried starting it... it ran alittle better for maybe 15 seconds then slowly died.

I tried to start it about 10 times thinking maybe it had to build pressure from the vacuum hose being disconnected, but ended with the same result. When I was trying to start it the gas pedal being pushed didn't cause any reving, it just stayed at idle. My dad noticed a gas smell and there was a small puddle of gas under the truck and some was dripping on the exhaust and causing smoke. I tried to start again and it sounded like the engine seized up. I had to take another break because by this time I was really mad. I waited about 5 hours then tried starting it again.

It didn't start the first two times i tried but then started and ran better than earlier but then died. So I tried again while pressing the gas pedal and it raised the rpm from about 400rpm to 1500rpm and immediately died when i released the pedal. After doing this the gas smell was back. Here's a pic of where the gas leaked on the exhaust:



Other things I noticed while doing all this:
It seemed like the torx screws had stripped out the holes to where the FPR bracket connected. I tugged on it to see if it would pop out but it didn't come out.

There was no o-ring on the FPR that I pulled out and the new one wouldn't fit with it on.

The back right plenum bolt was semi-loose when I was originally taking off the plenum.

Do you have to do anything when replacing the Dist. cap and rotor besides just take off the old and put on the new?






I didn't have a torque wrench so I had to make due with snugging them down pretty tight.

If I have to re-pull the plenum, do i need another new gasket??

Also, what is this hole? It has alot of buildup.



My dad thinks it may be the timing but i'm not sure if that would account for the gas leak. It is obviously something that I didn't do correctly, because there was no gas leak before I started this job.

I am stuck 100 miles from home with my 1 year old daughter and girlfriend and have to be back to work on monday...

Someone please help with what to do next or what to look for!!

Repaired image links