gergstuff

Ok, maybe a little melodramatic but still...I was driving home from work today had to cross a busy road. Saw an opening and hit the gas car took off but once I hit about half throttle the engine cut out! I freaked but backed off the throttle and engine function returned to normal and I made it across in the nick if time.

A liittle background, it is an 87 l98 and I only recently got it back together after having the heads off due to a broken valve spring. Thanks again to this forum for helping me get it back together and running.

I put in a new egr, new o2 sensor (had a code for that), new cap, rotor, wires and plugs, new battery and alternator.

I did some thread searching and found some similar posts with a lot of possible issues to investigate but seemingly no firm conclusions. Not sure of the best place to start.

under normal driving conditions the car runs great. I tried to duplicate the issue at the next 2 stops where there was no danger of getting creamed, same result, push the accelerator too far and engine cuts out only to return to normal after backing off.

maybe someone can walk me through the best steps to confirm or rule out all the possibilities?

anyone want to buy an 87 rag top?

also blew a tire today hitting a pot hole...

thanks

craig

Cliff Harris

Is the tank full of fuel?

FrankieD

faulty TPS (throttle position sensor)?? Check using a DVM if you get a linear voltage reading while opening the throttle blade.

gergstuff

Yes, tank is full, or at least the gauge is showing it is full.

OK, will find my digital volt meter and see what it tells me.

Dt86

Any codes?

gergstuff

Forget to check for codes last night was wrestling with the spare tire tray and trying to figure out some electrical glitches. I am adding that to my list of things to do.

kg4fku

Can you replicate the stalling situation while the car is not moving (car in park or neutral)? Does it happen at a consistent RPM or is it throttle (gas pedal) position sensitive only? Is it a sharp increase in throttle position or can it be replicated with a gradual or slow increase in RPM?

Could be a TPS or fuel pump issue. However, it could be an electrical gremlin as you mentioned completing some tune up items as well.

"I put in a new egr, new o2 sensor (had a code for that), new cap, rotor, wires and plugs, new battery and alternator."

I am "assuming" this issue did not exist prior to your maintenance.

I recommend verifying that the cap and rotor are seated and fixed and the alternator and battery have good connections. This is a quick check and will offer some sanity. I missed a distributor cap lug (90 degree twist J-style) one time and the car would not run right but only during certain conditions. I have a few more grey hairs because of that oversight. Not saying this is your issue but best thing is to recheck everything you touched to rule out an error on your part before chasing ghosts and rabbits.

gergstuff

I have not tried to replicate the issue at a standstill. It seems to be gas pedal position sensitive, push it so far and the engine cuts out. It happened this morning when I was driving it to the upholstery shop to get the top fixed.

I do not really know if it had this issue before I did all the things mentioned, it was not really driveable when I got it, had a broken valve spring. So, it could have had this problem before.

Certainly not a bad idea to re-check all my work performed thus far.

Aardwolf

I have had that happened in the past and it is a shock to pull out into traffic and have the engine stall. In my case it was a bad MAF.

gergstuff

Its like a christmas miricle, except it isnt christmas.

the comment above about a full tank of gas got me thinking, I have driven 80 miles and the gas gauge was still showing full. When I got in it today to drive home I hadnt travelled more than a mile when the gas gauge promptly dropped to half and then kept going down to just below a quarter tank. I stopped at the gas station and filled up took 18 gallons then I hit the pump limit for credit card use, not sure how big the tank is. Anyhoo, I jumped on it leving the station and excepting a slight hesitation it took off like a scared rabbit and did not cut out, so it seems like problem solved!

who knew...?

thanks for the input and what an odd thing for it to do.

I love these simple fixes.

now I guess I have to figure out what's up with the gas gauge. Or is that normal?

craig

captainkawasaki

I asked the same question once.
I was at Corvettes at Carlisle and one of the presenters (his name escapes me) told me that there was a bladder inside the tank that peels from the sides of the tank and prevents the fuel sending unit arm from moving.
Also in regards to your low gas acceleration problem you'll also find that it gets you in corners too, mine starts cutting out in hard corners just under half a tank.