Well i been trying to nail this problem in the butt for a while and ive posted on it a few times. I have seem some people with very similar problems but all seem to fix it in diff ways. So, im gonna repost and if i cant dix this problem im jsut gonna live with it.

My problem is my car stumbles real bad for the first 5 minutes or so in the morning. i start the car and it will start the idle will surge for a second go to about 900 and the car will be fine. As soon as i touch the gas it putts and stutters and almost dies. Problem completely disappears after its warmed up for about 5 minutes. After that the car usually starts fine and doesnt hesitate at all. If i let it sit for a long time though the problem comes back. Doesnt matter whether its 90 degrees out or 5 below same problem

THings fixed/replaced/set: Timing set at 6 base(factory), tps set at .54, new plugs, wires, o2 sensor, cap and rotor, cts, fuel filter, fuel pressure tested and was right on the money, fuel regualtor showed no signs of leaking.

Im stumped guys, I have read sumthing aobut a pick up coil not sure if thats the problem. THe car is also running rich. Suggestions Please!!

 

injectors might be bad?

 

hmm yea i was gonna have the injectors checked out but y would it only happen in the morning. wouldnt it be happening all the time?

 

maybe they're cold or somethin and everything doesn't work right? I really dunno for sure, just thought I would give the obvious injector answer because that kinda sounds like that is what it is.

 

I'm in Homer Glen. If you want I could try to come over and scan the car to see if I notice anything out of the ordinary. I don't have any experience with MAF cars though.

 

Thought I would try & help, bear with me I've got a splitten head-ache from my neck being out of wack due to a guy who rearended me a while back as well as teaching 7 classes to students that don't care if they learn anything.

You say the car stumbles and/or hesitates when its cold. These two conditions are the result of a leaning of the fuel mixture.

I noticed that you've adjusted the TPS. This sensor uses a wiper to change the resistance thereby changing the voltage. They've been known to develope gliches. I would put a VOM on it and watch the voltage as the throttle is moved by hand.

When checking sensors, this site has some good testing info
http://www.fluke.com/application_not...AGID=1&SID=103

An inopertive EGR system has been known to cause a engine to run rich. On the other hand, vacuum leaks will cause it to run lean.

I checked alldata site and didn't see anything off-hand. For a car to have both a lean and rich problem there has to be a problem.

You should be able to pull the codes out of the ECM by cycling the key on-off, on-off, and then back on. Watch the chech engine light, count & record the flashes. These codes will help determine your problem. Remember that when dealing with EFI, you have cause and effect: one part can effect and cause other parts to go bad. Post the codes you find and sometime tomorrow or Sat I'll check back and see what you found.

Bill

I may live in Georgia, but I was born and raised in Mt. Vernon

 

Have you solved your problem yet? If not, I might have an answer for you. How old is your car's cat?

I've had a cold-engine stumble for years! But it only did it on the first start-up of the day IF I didn't let it warm-up first. After that, or if it's warmed-up, it's always run great, and it's always restarted well. Besides, with the clutch, I've always been able to control it, so I've never worried about it.

But I've been installing a new Y-pipe lately, and I've been having some fitment issues which led to some new words in my vocabulary, lol, and to me purchasing a new cat. My old one still passed my CA emissions test in 2003, but it's 17 years old! So why not, right? Well, I started the car today for the first time since installing the new cat, and it didn't stumble at all! It was like new. How about that, lol!

But it's not like checking something with a gauge, or making a simple adjustment to some sensor. There's some work AND money involved, so I'm not saying run out and get a new cat. But if yours is pretty old anyway, and if you haven't cured your problem yet, you might consider it. At worst, your car will be running more cleanly, right?

 

elcamino77 may be on to something for you. I had a similar problem on my 91's 305TPI setup that was very similar to your symptoms. Mine gradually got worse over time, too. I would also occasionally get a SES light while cruising at 70MPH, but sometimes it would go out by itself, and alway reset on restart of motor so I could never get the code it was trying to tell me.

I tore off the plenum and runner, which were all full of carbon/soot. Got down to my EGR, and it was bad. Would work very slowly and slowly leak down (vacuum wouldn't hold it). I replaced my EGR, cleaned my runners and plenum of all the soot, put in a 180 thermostat instead of the 160 it had (a little warmer temps help combustion), and solved my problem.

Although as he says, a vaccum leak could cause this too. Might replace the vacuum hoses when you put it back together. Can't hurt! Not an expensive fix if you do it yourself, but plan on a full afternoon the first time your try to remove and replace the runners. Be sure to use new runner and plenum gaskets, too.

Hope this helps. Have a great day!!!

. - Vern

 

Check out his other post in cooling. https://www.thirdgen.org/techbb2/sho...hreadid=231136
His fans are not coming on as well. This plus the fact he has both a lean and Rich condition tells me he either has several problems or that the ECM has seen better days. Best thing he can do at this point is to pull the codes otherwise we're just shooting in the dark. I personaly don't like Autozone, but they used to carry a ALDL Key that came with a manual. I'd invest in one of those and pull the codes. Then post them here so someone could help you find the answer.

Bill