Sick Buick

[RBruton]

Thought I would throw this out there for comments. Car was running fine, hit it pretty hard out on the freeway, got to the house and car was running very rough at idle but seemed fine out on the highway. At idle it was very rough and spitting out some black emissions. Didn't have time to mess with for a few days. Had already planned on putting in new O2 sensor and did. Checked for obvious things, plug wires, vacuum hoses, checked oil for any bad stuff(recently replaced head gaskets). Checked one plug and it looked good. Started and the motor would rev up to round 2000, idle down, choke and die. There are no error codes until I unplug something. I unplugged the MAF and the situation improved, car did not die but idles at 1500 rpm. This made me think I had a bad MAF sensor. Had a friend who had a good one(he says ), replaced mine with it and results were the same, car would start, rev up to round 2000, idle down, choke and die. Unplugged the replacement MAF and car would run at 1500 rpm. I tried changing chips without success. I can keep the car running with the MAF plugged but at above 1000 rpm. My friend still thinks its a vacuum leak or maybe a ground. I'm open to suggestions.

 

[esinger]

I had something similar happen to my GN. What happened was a valve got stuck open on one of the cylinders. A compression test on the cylinders showed zero compression on the cylinder with the stuck valve. Another simply thing we did was pull plug wires, taking one off and putting it back on , going through all cylinders. That narrowed it down to which side of the engine we were dealing with. The engine behaviour changed on the good side of the engine and didn't on the bad one (passenger side in my case).

I'm no expert, just letting you know happened in my situation.

 

[RBruton]

Thanks Eric, I appreciate the reply. I'm still trying to eliminate things as I go and have managed not to spend any money yet. I have swapped out the coil pac, swapped out the MAF, swapped out the IAC, swapped out chips just in case, checked for vacuum leaks and found none. EGR valve was loose but tightening didn't effect anything. . It's something simple otherwise the car would not run with the MAF disconnected. I going to check all plugs(ones in it are almost new) and check resistance on plugs before I start pulling any covers. I have ignition module that I may try since I have the borrowed part. I'm not getting any codes, the TPS setting may be alittle low so I'll try adjusting that as well. Thanks Again.

 

[Red Regal T]

Sure your intercooler hose connections are OK? Possible opening in your intercooler? Unmetered air will cause it to idle, but will cause a very rich condition and stalling if you try to drive it.

 

[RBruton]

If there is a leak I haven't found it yet. I have blown a hose off before when I first got the car. Thought with the loud pop I had really messed things up, limped it home cause it would hardly run. It's gotta be something simple cause it starts fine when I unplug the MAF and stays running. Thanks for the reply, I'll just keep trying different things. It's fortunate that sites like these are available for information and I have 5 to 6 friends locally that have these cars and have been through it all before with these cars. Think I'm gonna need to call a meeting and it be all around the frontend of my car

 

[LV GN]

You Should Check The Egr And The Egr Gasket

 

[RBruton]

Thanks I will check that, it was loose when I checked it the other evening, tried to tighten down the best I could, it is sure not easy to get to especially if your trying to save any special coating the valve covers might have on it. I did not replace that gasket so it could possibly be a problem. I did check the plug wires with a tester and they're ok. I only had a couple of new plugs lying around so I started checking on the passenger side and the first two were extremely gas fouled and black. After further discussion last night it was decided I need to make sure I'm getting good grounds especially on my ground lead from the battery that is fastened directly to the head that was painted when I had the valve job done(I didn't scrap any paint), also I need to make sure I'm getting a good ground on the coil pack because the intake w/ plenum attached was powdercoated(I did not scrape any there). I had another ground that comes off the firewall that attached to the intake under the gismo bracket that has vacuum hoses to the EGR valve and elsewhere. I just have it coated and looking good and you want me to take a sharp object to it, lol. Anyway I'm still on the learning curve and will start chipping away at the coating and see what happens.

 

[RBruton]

I'm gonna do what alot folks don't do and that's provide an end to the story. One of the replies I got was from LV GN which got me to thinking and I remember that I tried to use an existing gasket that was on the EGR valve. It didn't come with any of the parts I had bought to fix a blown head gasket and I thought it would suffice, wrong. I pulled the EGR valve last night to discover the gasket had failed and actually blew out which is a good reason why a few nights ago while I was searching for what else it might be I noticed the EGR valve was loose, I figured that all that might need to be done was tighten it back up but the problem was still there(a vacuum leak had always been suspect since the car ran fine after the repairs were made), motor would start, rev up, settled back down, choke and die. I had swapped out the MAF, IAC, coil (luckily I have friends with spares or from upgrades) so I wasn't out any money. I checked for vacuum leaks, checked grounds, checked my plug wires, checked settings on the scan master, had no error codes unless I unplugged something,swapped chips, was about to change plugs(but will still do tomorrow along with put all my parts back on), unplugged this and that when I got the reply from LV GN who was right on the money and jogged my memory about the gasket. A $1.99 gasket was all that was wrong. This Buick is alive and on the road to recovery, just need to tune it some, been needing that for a long time though. Thanks to all who replied, it kept me going when I felt giving up.

 

[LV GN]

thats great! glad you got it running right.

 

[RBruton]

I'm just glad you mentioned it, that was enough to make me take a second look, good job.