Random stalling? **NOW WITH CODES**

[Freak SHO]

Car: 1989 SHO

Mods: Stock except for Al SFB's, rear STB, K&N dropin, and Dynomax catback.

Problem: When I start the car first thing in the morning it fires right up. I usually let it warm for 3-5 minutes, (depending on temp, between 15-35f), and when I start to pull out of my driveway, the car will stall if not revved high (~2.5k). Far different than normal, it feels kind of fuel starved, sputtering at first when you try to rev. The major problem is, when it stalls, it won't start for another 3-5 minutes and when it does, it will stall again unless revved high enough to keep the engine running, (again ~2.5k). When I do finally get her running after much cursing, the exhaust smells VERY rich. Perhaps the oddest thing of all is that the car acts COMPLETELY normal after travelling 100ft.

Points of consideration:
-Driveway is angled downward, ~10 degrees
-Small a/f leak at the lower rad hose or resivoir tank, (fixing this weekend)
-Tach moves while cranking, (rule out CPS?)
-It may just be me, but I think the car runs too cold, (usually below "L"). It does warm up in traffic to between the "R" and "M." Could it be staying in the cold loop?
-Fuel pump seems quieter than usual, I can hear it, but just barely, (no whine, just hum)

Any ideas? Thanks for reading and any potential replies.

Ben

<small>[ December 29, 2003, 09:54 AM: Message edited by: Freak SHO ]</small>

 

[redalfa164]

Try cleaning map sensor

 

[AutoSHO]

Hmm. That is an interesting one. Have you pulled the codes yet? That would be the first thing to check. If I had to guess I would say either the MAF sensor is dirty or the ECT sensor isn't doing its job. But the computer probably has the answer waiting for you!

 

[wood_e]

I say clean the MAF for now

 

[projectSHO89]

As always, unplug the MAF sensor and see what happens. If your problem is still there, the problem is not the MAF sensor.

The MAP sensor is not cleanable. Probably a typo.

Steve

 

[Freak SHO]

OK, so amongst other things over the holiday weekend, I ran my codes to hopefully shed some light on my 'situation.'

Here's what I got:

KOEO: First test came back "11" all systems ok, same for stored codes, all that came back was "11." Then I ran the test again after testing KOER and it came back with a "24 - Intake air temp (IAT) or vane air temp (VAT) sensor out of range." Is this referring to two different sensors or two different names for one sensor? Is it the small one at the bottom of the airbox? Can this be purchased at a nat'l auto supply store like Autozone? (3 questions for KOEO)

KOER: Came back with a "21 - Engine coolant temp (ECT) sensor out of range." This would mean the sender is bad? The sender is located near the thermostat correct? I'm thinking this is why my gague is reading low, (shouldn't I?). Also, the car read a "91 - System running lean transmission SS1 circuit solenoid problem." This needs to be interpreted for me...and the "t" word scares the **** out of me...oh well, time for a refresh? (4 questions for KOER).

Any details still needed? Thanks in advance for any replies... thumb

 

[projectSHO89]

If ambient temp was below 50F, ignore the 24 code.

Was your engine at operating temp for the KOER test? This is a pre-requisite and will cause a 21 error if this condition is not met.

The 91 code indicates that an O2 sensor was reading out of range. Again, did you follow the prerequites of both warming the eninge to operating temps and to run the engine at 1500 RPM for two minutes (to heat the O2 sensors) immediately prior to running the KOER test? Your MTX-equipped car does not have shift solenoids. That code (and many more) must be read in the proper context based upon model and the mode of testing, whether it is a continuous code or is a KOER or KOEO code.

None of the codes posted would likely point to the cause your original symptom.

Did you follow my previous suggestion to unplug the MAF sensor and see what happens? You didn't say that you did so my guess is that you ignored my advice.

Steve

<small>[ December 29, 2003, 10:28 AM: Message edited by: projectSHO89 ]</small>

 

[Freak SHO]

Didn't ignore, just forgot to post it...

I tried unplugging the MAF on two separate mornings and I didn't experience the problem either time...I can't draw any definite conclusions though since it hasn't done it the last two mornings with the MAF plugged in. (it's been a lot warmer -- ~45 degrees)

I'll try running the codes again after warming today at lunch...results to follow.

Thanks...keep 'em coming!


----------AFTER LUNCH----------

So not only did I run the codes again, I unplugged the MAF for a 10 minute spirited drive to the beach. Seemed a little sluggish and horribly lopey idle between 750-1500. Ran the codes - everything came back ok...all 11's across the board...

ANY IDEAS??? I'm stymied. shrug

<small>[ December 29, 2003, 04:32 PM: Message edited by: Freak SHO ]</small>