E85 - Hunting Idle - SD1

Jerryl

Tall Unvaccinated Chinese Guy
Joined
Dec 14, 2004
Helping a buddy of mine out and not sure if this is E85 related but the car is on E85. The car has power logger and SD1 at default settings.

FP is 44 static. Cold starts fine and stays on cell 10. Once warmed up, it had a real bad hunting idle. WB fluctuates from high 10's to mid 13's.

Bat Voltage 13.8
Full Racetronix double pumper kit
Full tank of fresh E85
80lb injectors, high-Z

We removed the PVC and kept the port open and the car smoothes right out.
Disconnected the up pipe and no difference.
Sprayed some cleaner on hoses etc, no difference.
Went rich on hot idle fuel (10.5 :1) no difference.
Disconnected cam sensor, no difference
Tried another computer and PL, no difference.

Getting my arse kicked. Lol
Any ideas?
 
I would look at the MAP signal. Make sure the MAP sensor is getting 5v and ground from the ECM (from the TPS 5v and ground).

If you want to send me a log of the idle, I'll take a look.
 
Thanks Eric!!!
MAP uses the Alky Control pig tail gizmo.
Vacuum is about 16. Will look at the car later and send a log.
 
We removed the PVC and kept the port open and the car smoothes right out.

I would try to log this condition and see what changes between PCV or no PCV. I think it will go back to the MAP signal somehow (whether electrical or actual vacuum reading).
 
Send me the log also Jerryl


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Need the wideband and MAP type


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Have you tried changing the timing at idle ? I had the same issue and I just played around with the spark and VE table to fix it . It defiantly needs to be richer at least for me .
 
3 Bar GM from AlkyControl (Already told him to go SSI)
AEM gage type. (Whatever the model is)
Less than 50 miles on these parts.
 
Have you tried changing the timing at idle ? I had the same issue and I just played around with the spark and VE table to fix it . It defiantly needs to be richer at least for me .
No way to change timing at idle with SD1.
 
FYI, can't use the SSI sensor with the old SD1 chip, only the GM style 3-bar. The calibration is hard coded in the chip. The SD2 can use anything.
 
And I belive Eric takes trade in or at least he did for me . I had a sd1 that I upgraded to the SD2
Yeah, Eric is absolutely fantastic, and not worried about that. Will try to post a log later.
 
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