halo_bone

Alright guys, here is a detailed description of the symptoms as I have noticed them. The problem is that the car, my 89 LX, is stalling and dying on low RPMs, but, it only happens in specific conditions--just driving it around town on short trips, you would never know it had a problem. More details:
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- only in hot weather--runs long distances/perdiods of time, then idles without dying no problem at night.

- only after engine is warm, after running for longer distance or period of time

- only when slower engine rpm OR in lower gears. It stalled in 5th at 65mph. But if you stay in 4th and stay over 2000 rpm, it will keep running. Until you slow down for an exit, stop sign, traffic signal--it'll stall as you slow down, as the rpms go down, and as you have to use the clutch (putting it's rpm to idle speed).

Actually, by "stalling", it will try to keep running. In this (above) state, it will putter away at the stop light. Trying to rev the engine (not in gear), it acts like it's not getting gas and only continues to sputter. When the signal changes and you try to take off, it will putter for a few meters if lucky, then die.

Now, at this point, being immediately after it dies, it will still start up--but only into the sputtery condition. It ignites fine, but barely keeps running, and putting it into gear to try to drive, will kill it again.

Turn around seems to be 5-10 mins. Wait for 10 minutes, it will start up just fine again, and drive without dying--provided you get going fast enough to keep those high rpms before it gets hot enough to sputter out. I'll have problems at any RPM in 1st/2nd (acting like it can't get gas), 3rd seems to be a threshold (works but you can 'feel' the bad gas input), and keeping it over 2000 rpm in 4th/5th you wouldn't know there was a problem. Another stop sign or traffic signal is bad news.

Again, this is non existent at night / cooler weather. I waited until dark, then drove it around town and on the highway with zero problems back home. At the end of the trip home (night time), it didn't die at any traffic signals, and I let it idle for about 15 minutes to see if it would die, which it didn't.

Fuel mixture gets confused in hot weather? Vapor problem?

What is your take?

Appreciate the input!


Tyler ( )

88 347 stroker

i am having the same problem except my car dosent start up right away it just cranks. after a few min's it starts up fine and it seems ok. then it dies out again at low rpm's. mine isnt affected by hot weather only, it was a nice cool day and it did it. im realy lost and confused. any help would be great.

mattdel

it could be a BAP sensor problem, but i'm gonna lean towards an issue with the ignition module(TFI), which is bolted to the front of the distributor. they are notorious for heat related problems, and generally take about 10 minutes to cool down to a driveable condition.

It sits almost directly behind the fan, so this is another reason the higher RPMs are running better, as airflow over the module is increased with a clutch fan.

88 347 stroker

Im going to pick up a BAP sensor n give that a shot, i just bought a summit racing distributor (to replace the crap MSD one i had) and it has a brand new TFI. who knows it very well may be he TFI but ill give the BAP sensor a shot. thanks for the advice

88 347 stroker

im going to have to do some research bec i converted my speed density to mas air n i dont think i ever replaced my Manifold Pressure sensor (for speed density) with a Barometric Pressure sensor (for mas air) im not sure how that will affect the car overall. im going to get the numbers off the ECU and get the correct sensor for that computer.