I searched all night for answers, but can't find anything possible after the coil or o2 sensor. Anyway, the car is running real rough after it warms up. It will barely run at idle and stalls. any other things too look at> ?

 

sounds like a bad MAF to me

 

Or the IAC or a vacuum leak

 

procedure to check these?

 

I was told to check my MAF like this:


Start the car, bad idle? If so, turn off the car, unplug MAF, and restart. If there is a better idle (might be high though), it is most likely your MAF.

 

I followed that procedure...most likely not the MAF. other ideas?

 

Pull any codes?

 

I'm thinking EGR (if you're still using one).

Even if you have no EGR related codes the EGR valve could still be bad or stuck.

 

you can also try cleaning the thottle body with some 2+2 on a rag and run your fingers throught it, best bet is take it off and clean it, which is what i have to do on her car, but i did carb clean on the rag and it helped her car out alot, but it was carboned pretty bad.

 

iroczTHe 5.7: I don't have a scanner, nor do I know how to use it. anybody have a scanner that lives on long island so I can see if there are codes? I am in Brookhaven.
zz3,
what would a bad egr do? It was wroking fine before the last motor blew....I can assume that it is still okay. it's not to old either.
Don,
The TB is clean.
Thanks for the replies guys:
I'm going to replace the coil, check the TPS voltage if I can figure out how to, replace the o2 sensor and check for burnt wires.
Any other ideas?

 

You don't need a scanner to see what codes it is thowing.

©Vader:

First, you'll need to acquire a GM OBD I ECM Diagnostic Trouble Code Retrieval Tool (commonly known as a paper clip to TGO members).

With the engine and ignition turned off, locate the ALDL connector under the dash, just to the right of the steering wheel in the driver's foot well area on Firebirds, and on the left on Camaros. There should be a small rectangular cover over the access hole in the lower dash trim.



Insert a tool as described above (paper clip) into the 'A' and 'B' terminals on the ALDL connector:



WITHOUT STARTING the engine, turn the ignition to the "RUN" position. Watch the Malfunction Indicator Lamp (MIL) - it will begin to flash. This is also commonly called the "Service Engine Soon" or "SES" lamp. The first code will flash three times, and will usually be a code '12'. This is encoded by one flash of the lamp, a brief pause, then two successive flashes of the lamp. Each code will repeat three times, so you should see a "Code 12" flash three times. Any other error codes will follow in numerical order, and each code should flash three times. After all codes have been displayed three times, the "Code 12" will again flash three times, then all other codes will follow as described earlier. This cycle will continue until the jumper is removed or the ignition is turned off.

After you have made a note of all error codes, turn off the ignition and remove the jumper immediately. If you forget to remove the jumper and attempt to start the engine with it in place, you could damage the ECM. For this reason you should remove it immediately.

 

all i got is a code 12, over and over, quite a few times....how long does it take for a code to be in the motor? I had disconnected the battery and only driven a mile or 2 before i did this test (becaseu the car is running too bad to drive further.). what is a code 12?

 

Code 12 just means it is in diagnostic mode. Seems like your not throwing any codes. Did the SES light ever turn on before you disconnected the battery?

 

no, never got an SES light before either, you know I've been through hell with this new motor....first no oil pressure, then after that was fixed, no fuel which turned out to be a rresult of no oil pressure again, but I think that was just a clogged sender i guess, cause it works now after i replaced the pump fuse and the pressure is reading normal on the gauge....I am getting fed up, but you guys got me this far.....but I really gotta get this thing running. please help!

 

Well, i'd start with the small stuff.

Iac - http://iroczone.com/techartcleaniac.html

For the hell of it, it's easy, TPS- http://iroczone.com/techarttpsadj.html

I'd really try finding someone who you can borrow their MAF for a little, and put it on your car.

I had similiar problems, but I threw a MAF code. I replaced both the MAF power and burn off relay and it fixed the problem.

 

Check for vacuum leaks or if its a new engine did you have all the emissions hoses hooked up properly as per the diagram sticker on your hood? Check your grounds and make sure there nice and tight and not loosed and grouded properly. Reseting your TPS sensor and IAC would help out also. You mention the car stalls after it warms up which is probably in closed loop. When in closed loop, if the car stalls that could point out to the o2 sensor and wiring , the MAF and its related wiring or could also be a bad ECM once the car is in closed loop. I had a similar problem also and it turned out to be the MAF sensor. I don't want to say that it is and the best way would to try a known good one but if you don't have a spare and buy one that could be expensive and frustrating if it doesn't fix the problem. Do a good visual inspection of the engine compartment looking for wires that look suspicious or not connected properly.

Heres a quote from a member over at Turbobuick.com and what he suggested when I had problems troubleshooting my car:

"See what happens is the maf sends the ecm a signal indicating how much air is going past it, based on that information... it then gets the reading from your O2 sensor..looks at other things like TPS, load, etc.. and makes a fueling adjustment.

Between point A(MAF) and point Z(O2) there are a lot of parts... A bad MAF or O2 will have you scratching your head trying to get the car sorted out.

Best tools you can have to work on these cars is known good spares.

Coil pack ign module, MAF, ECM, and a spare known good chip. Having these items narrows down your searches BIG time.. start collecting them at the rite price..they will always be worth their weight in gold."

This was on my 89TTA.

The more you could tell us about your problem in detail the easier it could be to attempt to pinpoint a solution.

Keep us posted.


__________________

 

had issues like that when my fuel pump was on its last leg. Check your fuel pressure

 

He alll, thanks for the replies:
I will investigate these things. I have some spare MAFs I think. I think I have my stock coil. I'll buy a new o2 sensor and try to adjust the TPS etc. I appreciate the comments. I think the fule pump is okay, the pressure gauge says so, and so does the stoichmeter. I will give a good visual too. Please keep the ideas coming, but this should give me plenty to work on this weekend. I thin the ignition module will be the alst thing i will look at beause they are expensive, right? well thanks....i'll keep posting updates./ -J

 

Problems that onset after warmup are typically either the O2 sensor or the Coolant Temp Sender.

If it's the O2 sensor, the ECM ignores it until the engine is warmed up so things run OK until then. ECM then sees the engine's at temp, starts listening to the O2 sensor, gets bad data, and makes the engine run badly.

If it's the Coolant Temp Sender, the ECM never sees the engine get to operating temp so it's stuck in Open Loop mode...and can't adjust fueling, so the engine runs badly.

You can throw parts at it pretty cheap in this case, but long term you'll want to get a scanner. Stick with Delco sensors for the O2 and Coolant Temp, avoid the cheapo stuff here. Maybe NAPA Echlin if they're handy, but no GP Sorensen or the other China stuff.

 

great i'll start there too! thanks.

 

well, part of it was burnt plug wires...I taped them up and the car atleast started. After it heated up it was runnig crappy again, but i think that is becasu the tape probably burned. I'll replace the wires and keep you guys posted.

 

As of now, the car runs, but will idle at 800 rpms.....but then when you rev it and it comes back down...it'll idle at 1500 rpms. Then sometimes in gear when it is hot....it idles at 4oo rpm and sounds like it wants to die...ideas?

 

my new motor is a piecve of crap I am fed up. I am to the point where i am thinking of parting out. ANYONE ON LI that can help would be greatly appreciated! I WILL PAY CASH to a mechianic to come and do diagnostics! (or get it running). HELP> I am fed up. I am really counting on you guys to help me out here....problem is, you all have great ideas.....but i dont' want to change ever sensor blindly...not only is that not cost effective, but i am totally fed up here. I could even flat bed it to a good hsop, but none of the performance places even want to touch it..The Car is not throwing any codes,...so I don't think it's a MAF. plus i disconnected it and it doesn't seem to run any different. I took apart the timing cover today to see if the cam to crank gears were out of sink, but they are not. Just curious, what if the crank gear was installed incorrectly on the A or R? It looks like it was on at 0, but would it even run if it wasn't. The car sounds like it's running out of valave timing. But again, i check the cam gear position and it's correct. I guess it could be a valve hanging open, or a sensor, or an intake leak or a million other thiings....I don't know what to do! please help! thanks

 

ya say it runs like crap after it warms up, im willing to bet its your coolant temp sensor like KevinC mentioned. my 86 S-10 would do the same thing, i would get to a certain area on the interstate and it would goof up, lose power and so on.
i replaced the CTS and it ran MUCH better after that.

 

well it also rus bad cold, but not as bad, but it's harder to start cold.