Viprklr

iTrader: (5)

Lots of bad running hot threads but I didn't come across any cold running problems with decent hot running.

88 TA 350 TPI
This car now idles fine. Datalogging showed me that a new O2 was required, done. Among many replacement parts, some people don't deserve to own cars, this car is finally running good. EXCEPT when cold.
It has a bad hesitation while driving cold for about 3 minutes and then it clears up. The idle is perfect. Runs just fine when warmed up.
It came with a new MAF and I replaced the power relay. FP is holding nicely at 43. Vacuum is a solid 20. The CTS shows me a believable value. Grams/sec is around 2.5 at idle. BLM's and Integrators are now within 4 of 128 with the replacement O2. The TPS was a bit low at .44, now set to .55.
I have yet to check the IAC but short of listening to it with the stethoscope, it does audibly change the controlled "vacuum leak" sound.

Ideas? Thoughts? Guesses? Theories? even Wild Goose Chases?

This is the last problem that I need to address before I can sell it.

Reid Fleming

iTrader: (2)

You and I have similar issues. My car on a "cold start" (cold start being starting the car in the morning when it's 90°F outside) will go to 900 RPM and stay there. It won't jump up to 1200 for those couple of seconds then gradually come down to idle.

After it's sat at 900 RPM (idling rough, sounds like a big cam, wanting to stall). I'll give it a blip on the gas and it will sooth things out a bit. But shifting into gear, the car is low RPM. 700'ish. But pressing the gas pedal results in a dead spot of no power. When it does make power, it feels like the emergency brake is on type of thing.

After about 4 blocks when the car has warmed up to 150°ish coolant temps, it will idle fine. Smooth. But that initial cold start is terrible. Shutting the car off when it's warmed up, it will start up without issue.

I cleaned the IAC out about 8 months ago. Ran great after doing that. I've tried setting the min idle for everything from 450 to 650 in Drive. TPS is at .575 volts.

I took the PCMForLess chip out last year because it was knocking at WOT or at idle when the temperature was high. (knock sensor on the chip is disabled) and put in my old Hypertech Thermomaster. The ECM is a few weeks old. But it scans at the same TPS setting as what the multimeter at the TPS reads.

Base timing is 6°.

A mechanic set the fuel pressure at 58 psi (I asked why. He said the BLM's were at 160 and turning the pressure up there got the BLM's down lower....I don't know about BLM's, what's good, what's not). I backed it back down to 47 psi and the car idled smoother in the driveway. But the same darn rough idle at cold start up. Injectors are Bosch III's. About 6 months old.

Once the car is warmed up (180-200°F), it will idle at 500-650 RPM in gear. Anything below 650 RPM's and the alternator voltage drops. I have a digital volt meter plugged into my cigarette lighter. This means if I'm stuck in traffic in gear for a long time, my battery will start to drain.

Cliff's notes: rough low idle at cold start. Too low of an idle while stopped in gear.

regal301

i had the same problem,couldent find anything wrong with anything.so on an expensive educated guess i put a stand alone speed density harness 90-92 style with 7730 ecm and as i figured it fixed ALL of the quirky things about the car,including the cold driving deadspots.

http://www.larryselectricsite.com/products.html

came with new harness,ecm,prom about 400 shipped.
the speed density system runs soooo much better!!!!!faster smarter ecm!!!!
NOW I ENJOY DRIVING MY CAR !!!!!!