The cold restart may be due to a cold start control (for the cold start injector) that is a little sluggish. If the mixture seems correct in closed loop mode.after warmup, you may want to make sure the cold start control is not recycling too fast. It relies on coolant temperature to enable it, so if the cooling system is not clean, it may be slightly insulated. Flushed lately?
As for the TCC lockup, the '86 models had a relatively low lockup point. The factory had a "fix" for this and some other inherent problems with the programming in a revised PROM offered in October of 1986 - After the last '86 model was made. There was a TSB regarding this problem.
A copy of a General Motors TSB for ‘86 LB9 (Camaro IROC is the same)
Code:
PONTIAC ROUGH IDLE, CHUGGLE, LOW SPEED. Page: 1
86-6(GAS)-66 Issued: 10/17/86
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1986 FIREBIRD VEHICLES WITH 5.0L LB9
TPI ENGINE (ENGINE CODE F)
New service calibrators (Ref: Called Mem-Cal In Shop Manual) have been
released for the 1986 Firebirds with the 5.OL TPI engine. These new
calibrators will address the following customer comments:
1. "Rough Idle" on both hot and cold engine - the idle speed is raised to 650
plus or minus 50 RPM.
2. "Chuggle or Shudder" at low speeds - torque converter clutch (TCC)
engagement speed is raised to 41 MPH.
3. "Hesitation" on light acceleration with a hot engine.
4. "Cold Driveability" - New calibration eliminates light to moderate sag on
cold driveaway.
5. "Service Engine Soon” Lights - Eliminates the following false Codes:
A. Code 32 - EGR System failure
B. Code 33 - Mass Airflow Sensor Voltage High
C. Code 34 - Mass Airflow Sensor Voltage Low
D. Code 43 - Electronic Spark Control
E. Code 44 - Lean Exhaust Indication
If normal engine diagnostics and repair do not correct the above conditions,
it will be necessary to replace the calibrator in the ECM. Below is a listing
of the new calibrators and their usages.
ON AIR CONDITIONING (C-6O) FIREBIRDS
With QYZ (P215/65 R 15/N 15" Tire) Use - 1228290 Calibrator
With QAC (P235/60 VR 15N Tire) Use - 1228291 Calibrator
With QDZ (P245/50 VR 16N Tire) Use - 1228291 Calibrator
ON NON-AIR CONDITIONING (C-41) FIREBIRDS
With QYZ (P215/65 R 15/N 15" Tire) Use - 1228292 Calibrator
With QAC (P235/60 VR 15N Tire) Use - 1228293 Calibrator
With QDZ (P245/50 VR 16N Tire) Use - 1228293 Calibrator
Use Applicable Labor Time and Operation Numbers.
For use in 1227165 ECM only.
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ECM/Cal-Pak (PROM) for Model Year / Engine
YR. ENGINE OPTIONS P/N PROM CODE(S)
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86 5.0-F A/C, VD1,VE1 (Export) 16061103 1107BLL
86 5.0-F A/C, VB4, BT7 (Export) 16061117 1120BLN
86 5.0-F Fed, Calif, A/C, 215/65/15 tires 1228290 3234ANY / 8958AMU
8969ANB / 8980ANY
8993AUM
86 5.0-F Fed, Calif, A/C, 235/60/15&16 tires 1228291 3236AUM / 8958AMU
8969ANB / 8980ANY
8993AUM
86 5.0-F Fed, Calif, Exc A/C, 215/65/15 tires 1228292 3240BTZ / 8964ANA
8975AND / 8987BTZ
8998AWC
86 5.0-F Fed, Calif, Exc A/C, 235/60/15&16 Tires 1228293 3243AWC / 8975AND
8987BTZ / 8998AWC
86 5.0-F VD1, VE1 Exc A/C (Export) 16059564 9567BUR
86 5.0-F VB4, VT7 Exc A/C (Export) 16059576 9580BUT
86 5.0-F Fed, Calif, A/C, 3.42(GU6) 16059000 9004AWD
86 5.0-F Fed, Calif, Exc A/C, 3.42(GU6) 16059006 9009AWF
- - - - - - - - - - - - - - - - - - - - - - - - - - - This item is from a Technical Service Bulletin, not a recall. Not all owners reported problems with their vehicle's performance, so there was no recall. However, just because problems were not reported, they still exist if the PROM has not been changed. If you remove the cover from the ECM, you can remove the PROM carrier. Inside the carrier are three ICs. One is a resistor network, one is an I/O buffer, and the large one if the PROM (memory chip). The PROM should have a label with a revision number, something like "DELCO AUM 6339". There should also be a set of numbers inked on the PROM. Four of these are the date code. If the date code is not 8646 (1986, 46th week) or higher, your PROM has never been changed.
The replacement has been programmed to raise the idle, enrich the mixture at mid range, hold off the torque converter clutch lockup to 41 MPH from 28 MPH, allow for a wider range of MAF signals, MAT signals, allow for a lower coolant temperature before entering full closed-loop operation, allow for richer O2 readings, and much more. Basically, you will notice a real difference in how your car operates.
I had a Hypertech Thermo Chip in my TA when I found out about the new PROM, and the GM reprogramming is better than the Hypertech in my opinion. The replacement only cost $63.00 from the dealer, and they were still available as of April of 1999.
Check this U.S. government web site for more details on TSBs and recalls:
http://www.nhtsa.dot.gov/cars/proble...ervicemmy1.cfm
The original PROM was replaced with an upgrade in October of 1986. My '86 TA was built in July, so I had the "bugged" PROM. Actually, there is nothing wrong with the original PROM, but the parameters were changed in the new programming. Instead of the torque conveter locking at 28MPH, it holds off until 41MPH. The threshold parameters for the O2 sensor, MAT, MAF, ESC, and EGR were all changed. The nuisance setting of Code Code 32 - EGR System failure, Code 33 - Mass Airflow Sensor Voltage High, Code 34 - Mass Airflow Sensor Voltage Low, Code 43 - Electronic Spark Control, Code 44 - Lean Exhaust Indication, were all virtually eliminated, and the idle was raised to 650 RPM. I had a Hypertech PROM in my ECM, but had switched back to the OEM after some experiences with Hypertech on a different vehicle.
I never experienced the codes, but my car runs completely different with the new PROM, like I installed a different engine. The part number for the replacement is exactly the same as the original. GM often changes part specifications without changing part numbers. The key is to look inside the PROM carrier (Cal-Pak) and check the label on the PROM itself. The revision level of the software is coded there. You should also check the date code inked on the PROM. It should be any number greater than 8644.
Code:
ON AIR CONDITIONING (C-6O) FIREBIRDS
With QYZ (P215/65 R 15/N 15" Tire) Use - 1228290 Calibrator
With QAC (P235/60 VR 15N Tire) Use - 1228291 Calibrator
With QDZ (P245/50 VR 16N Tire) Use - 1228291 Calibrator
ON NON-AIR CONDITIONING (C-41) FIREBIRDS
With QYZ (P215/65 R 15/N 15" Tire)Use - 1228292 Calibrator
With QAC (P235/60 VR 15N Tire) Use - 1228293 Calibrator
With QDZ (P245/50 VR 16N Tire) Use - 1228293 Calibrator Mine was 1228291, and cost $63.00 at the dealer in April of '99. They are still available.
If you are curious about any TSBs or recalls on any vehicle, check
http://www.nhtsa.dot.gov/cars/proble...ervicemmy1.cfm .
Our tax dollars pay for this, so we might as well use it.
BTW - If your dealer has no clue. I ran into the same thing. I had to show them a copy of the TSB pulled from the NTSB web site before they would look up the part. The next dealer I went to was much more helpful and knowledgeable. You just never know...
