90RS305

Ok guys....I got a strange one for ya...

I have a 1990 RS 305 (if you didn't figure that out already) that is having the STRANGEST problem I've ever come accross. Litterally based on the time of day (mainly the temperature outside) negates weither or not I can drive my car. If its 7:00am and somewhat cooler outside, I have to fight with my car tooth and nail to get it to go, sometimes for over 15-20min. It will not hold an idle at all, and if I so much as even try to give it more than a 1/5 throttle, NO engine response. I have to rapidly pump the gas pedal to get any response out of it. Once I finally have the car somewhat warm it will start to accellerate on its own without me pumping the gas, and I can finally get on my way. BTW at this point in time if the SES light hasn't come on yet it does at that point. Now here's the curveball.....if its like 4:00pm, when its considerably warmer outside, my car will usually start up with NO problems. I can drive it around without an issues. WTF?!

The only thing anyone could come up with was that the coolant temp sensor was sending my car screwy signals so I replaced that, to no avail. Also, I did try to get my codes pulled on the car, and when the guy put the prongs in my Aldl port, all the SES light did was blink very rapidly w/o stoping.

I'm stumped, and most of my shifts are opening shifts, so if ANYONE has ANY idea of what might be wrong with my car, PLEASE let me know!!

Thx,
Bruce (90RS305)

jstrdn90rs

Have you tried an exorcism?.. ...Just kidding..Thats is some curveball you got?..Two things I would be considering...One is looking at the TPS sensor.The computer looks at the CTS and TPS on cold start-up.I would check the voltage at both sensors when cold.Making sure you have your 5 volt reference on each sensor.
Second,that blinking rapidly is weird..I would be leaning into the computer itself.If you dont find anything on the first suggestion..possible bad PROM?ECM..I know Temple is hotter then $&%#,so at 7 am is not actually cool.Beautiful place though..ASU area rocks..

AlkyIROC

Blinking slowly means it's in open loop. When you go for a drive it will also blink quickly. That means it went into closed loop. It will switch back and forth as you drive. You can't get flash codes when the engine is running.

Other than things like TPS, IAC etc, the first thing I'd suggest is to install new injectors.

How old is the cap, rotor, plugs, wires, coil, O2 sensor?

The ECM coolant sensor is at the front of the intake. Gauge and warning light sensors are on other parts of the engine.

90RS305

We've narrowed it down to perdy much being the ECM. Gonna see if I can pick one up cheap (if not, autozone has them for 89.99) and just replace it. I'm sure I could use a plug job, but I know it wouldn't be causing this serious of a malfunction. But yeah, basically we figured out my car is stuck in closed loop, and won't go back to open loop for cold-start opperation. (I hope I got the closed/open in the right order, I always get them backwards, lol) I'll update as soon as we do that, so cross your fingers for me!.....

Raiderfan

Your car was born to work the night shift........

J/K bro, I really have no idea........good luck....

rwdtech

make sure you let us know if that solves it...ive been watching this thread

Rosadoc-Z

I had a similar situation but it didnt have to do so much with the idle. Every morning on my way to work (7-8 a.m.), my car would simply shut off on me while driving. It only takes 20 min to get to work but it would shut off 3-5 times and would take a few tries to start up back up. In the afternoon on my way back from work, the car ran fine. I tried checking everything and eventually concluded that the morning condensation was the only difference from morning and afternoon. I put di-electric grease all over the spark plug wire boots connecting to the distributor and the coil. Its been 2 months now and it has yet to shut off.