98 bonneville fires, starts and dies immediately

SDE

Well-known Member
I googled the problem and it said to replace the MAP sensor. $60 later and the problem is still here, if not worst. It will barely idle sometimes and sometimes it works perfectly. To get it to run, when this problem occurs, I need to give it some gas and use the left foot on the brake to shift it from Park and if I am only backing out of the garage, I need to keep giving it the extra gas and still brake with the left foot, or it will die. Yesterday I drove 150 yards down my road and it died when I let off the gas to go around a tight curve. Not good at all.
Any suggestions?
Thank you
SDE
 
Could be a fuel regulator or a bad throttle position sensor. I would check your fuel pressure and if that is good I would start with the throttle position sensor.
 
A friend had a similar problem. They thought it was a map sensor. It was the plastic hose that went from air filter to intake was cracked. She had to put car in park to make hers run properly. Putting car in gear, rocked the engine, opened up the crack. We made a temp repair with metal duct tape.
 
i HAD a 98 that did same thing. was a bad wire in harness going to fuel pump. a ground. it would die. and id have to hit the right rear door window switch a few times and id hear the fuel pump kick back on. id hit a bump or turn it die again.
 
Not familiar with the ignition setup on your Bonneville, but most vehicles have been set up to provide a hotter spark when starting than running for the last 30 or more years, whether they have standard or electronic ignition systems. On the older ones it was a contact on the solenoid that bypassed the dropping resister for the coil, on the newer ones it is done through the electronics. You may need to look into that, the circuit that provides spark in normal mode may be bad and it is only running on the start circuit.
 
Mass air flow sensor. See it all the time. Unplug the MAF and I will bet it runs. Not a cheap sensor, I recommend a new GM one if you depend on this car. The remans available are usually just cleaned up and will have similar issues in short order.
 
(quoted from post at 08:17:35 11/23/14) Mother in law had a 99 doing that. wanting to say the EGR valve was the culprit, but for some reason that doesn't sound right.

Yes. EGR is the first thing that comes to my mind. In the old days you could just pull the vacuum line off of it, plug the line, and the problem was cured. Probably more complicated than that on a '98.
 
I had something similar happen. It took a good mechanic a while to figure out that a sensor for the air conditioner had gone bad and was grounding the other sensors that were on the same circuit.
 
(quoted from post at 06:42:36 11/23/14) I googled the problem and it said to replace the MAP sensor. $60 later and the problem is still here, if not worst. It will barely idle sometimes and sometimes it works perfectly. To get it to run, when this problem occurs, I need to give it some gas and use the left foot on the brake to shift it from Park and if I am only backing out of the garage, I need to keep giving it the extra gas and still brake with the left foot, or it will die. Yesterday I drove 150 yards down my road and it died when I let off the gas to go around a tight curve. Not good at all.
Any suggestions?
Thank you
SDE

Need to put it on a scanner and see what the puter says. Last time I worked on a GM car that old with those symptoms the fuel pressure regulator was bad. But if you start throwing parts at it it's going to get expensive quick! That's why you need to have it scanned. Sure you may get lucky and get it on the first try with one 50 or more dollar parts but you may wind up changing 6 before you get it too.

Rick
 
My check engine light has been on for a couple of years now. It is an EGR valve problem. It did not occur to me to re check the codes to see if another problem is hiding there. I will try to get the codes read soon.
Thank you
SDE
 
I had a similar problem on a Chevy Citation and it was rust in the gas tank blocking the gas. I had installed a fuel pressure gauge and it would
drop. After dropping the gas tank and cleaning it fixed the problem. I also installed a new pump. Hal
 
How is your coolant level been lately ? I am pretty sure that is right in the years of the bad plastic upper intake manifolds. I would not totally discount it sucking in some antifreeze either.
 

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