problem with partial throttle, idle after adding some mods

gxnos

Founding Member
Apr 14, 2002
173
1
0
Birmingham, MI
'86 GT running a 76mm C&L MAF (converted from SD) and A9P computer. Just recently added a T70 single turbo setup and some E7 heads.

Before the turbo it ran perfect (with MAF conversion and everything). I added the turbo setup with FMS 42lb green top injectors, 255 walbro, E7 heads, and the green C&L calibration tube to run the injectors properly.

Started it up and it runs like crap. I have somewhat of an idea why, but I just can't get it to run right. I have the timing set at 10*, so the idle was really low. This made it surge really bad. I cranked in the throttle hard stop to get it to idle, now I have no partial throttle and it spits and pops at me under 10% throttle. I tried adjusting the TPS and some other things but I just can't get it. I also wanted to note I have an AEM wideband and A/F ratios are perfect at idle and above 10% throttle. When I hit boost, it pulls hard and A/F are in the 11s. Can anybody point me in the right direction here? Should be something simple I am missing.



See attachment for a pic of my setup
 

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tps voltage with engine off was 1.2V. i slotted my tps to get some adjustment out of it, cranked it back to about .8V off and it runs WAY BETTER. still a little hesitation, but no stalling, surging, etc.. now I think the rest will be in the tune.
 
MIGHT HELP NOT SURE

THE OPTIMUM SETTING FOR THE TPS IS .098 VOLTS.SET IT WITH THE KEY ON-ENGINE OFF FOR BEST RESULTS.CHECK AFTER SETTING WITH THE CAR RUNNING.IF YOU SET IT LETS SAY AT .099 VOLTS IT WILL BOUNCE OVER TO 1 VOLT AND YOU DONT WANT THAT.YOU ALSO DONT WANT IT BELOW .098 VOLTS EITHER.YOU SHOULD ALSO SET THE IDLE SCREW BACK TO THE FACTORY SETTING BECAUSE IT REALLY AFFECTS AFR EVEN IF YOUR GAUGE SHOWS A GOOD SETTING.YOU CAN BUY AN IDLE ADJUSTMENT PLATE FROM MUSTANGSUNLIMITED THAT BOLTS BETWEEN YOUR IDLE CONTROL SOLENOID OR IAC AND THE THROTTLE BODY.I INSTALLED A HIGH LIFT CAM AND COULDNT GET IT TO IDLE RIGHT USING ALOT OF DIFFERENT APPROACHES SO I PURCHASED THIS PLATE AND IT INSTANTLY TOOK CARE OF MY PROBLEM.ITS ABOUT 20 OR 30 BUCKS.OTHER COMPANYS ALSO CARRY IT BUT THATS THE SHOP I GOT MINE AT.ARE YOU ALSO SURE THAT YOUR FMU IS CALIBRATED AND WORKING PROPERLY?ANYWAYS JUST A FEW SUGGESTIONS.