Need some serious HELP!!!

[mbliss_00]

I have a 92 GT 5.0 5 speed, when it warms up or about 10 miles which ever comes first, the engine starts bucking and jerking really bad. Sometimes it will stall when idling. Seems to act worse when I press down on the gas. I have changed the fuel pump, fuel filter, map sensor, tfi module, plugs/wires, ignition coil and the coolant temp. sensor... Running out of ideas! And I don't want to get robbed at a shop! I know that it has to be something small... Any help or advise from here would be great.

[HiFlow5 0]

Originally Posted by mbliss_00

I have a 92 GT 5.0 5 speed, when it warms up or about 10 miles which ever comes first, the engine starts bucking and jerking really bad. Sometimes it will stall when idling. Seems to act worse when I press down on the gas. I have changed the fuel pump, fuel filter, map sensor, tfi module, plugs/wires, ignition coil and the coolant temp. sensor... Running out of ideas! And I don't want to get robbed at a shop! I know that it has to be something small... Any help or advise from here would be great.

Have you tried pulling codes yet? If not, I would start there.

[RAGNAROC]

I HAVE AN 85 GT COBRA AND THE EXACT SAME THING IS HAPPENING WITH MINE. JUST STARTED HAPPENING. i WAS JUST ABOUT TO CHANGE THE PLUGS, CAP N FUEL FILTER BUT NOW i DONT KNOW.

ANY IDEAS WOULD BE SWEET

[mbliss_00]

Man I've done so much to this thing! Cleaned EGR, IAC, MAF, MAP/BORO and the PCV!!! I"m about to check the timing now... Codes! Yeah I've pulled them several times, never the same... they never make any sense. Would a bad distributor cause this or even a leaky headgasket???

[HiFlow5 0]

You really need to address the codes your cmputer is throwing before you can go any further.

[68chevelle]

also, do stangs have some sort of fast idle cam or mecanisum? im sure they probably do. if your cars idel was set while cold it could have been set with the fast idle running, so when its on fast idle, (numbers are for example only) it would normaly be at like 1200RPM's, and someone set the idle when it was running on the fast idle to let say 800RPM's, then when it worms up and the fast idle goes off then it drops the idle down by 400 or so RPM's,(from 1200 to what would normaly be your 800rpm's). sence they set the fast idle at like 800, or so, it dropes it down by 400 when it goes off, to around 400RPM's total, (800-400=400 just explaning cuz i am confusing sometimes i know). i hope that actualy made sence. all it was saying is that if your idle was set while it was cold then when it worms up the idle will go down by a few hundred RPM's and cause it to have poor idle quality. do you have a tach in your car? if so look at it when you first start it, then after it worms up and is running bad look at it again and compare. when it is cold it should probably be at like 1000-1300 or so RPMs, anyone with a stang actauly know? and then when it worms up it should be at whatever the listed idle speed is for your car.

oh and like he said above, you really do need to take care of any codes first.

[thunderbird muscle]

Codes first it'll be a lot easier to diagnose if it is listed.

[mbliss_00]

KOEO- No Codes

KOER- 13 RPM OUT OF SPECS (NORMAL CURB IDLE)

MEMORY-53 TPS TO HIGH (ADJUSTED IT TO 90)
-63 TPS TO LOW????
-66 MAF SIGNAL LOW CIRCUIT GROUND
FUEL PRESSURE 41PSI (NORMAL RANGE 35-45PSI
TPS AND MAF SENSORS ARE WORKING PROPERLY....

[HiFlow5 0]

I'm will to bet you have a bad TPS sensor, and when the engine heats up its playing games with the sensor. If a sensor is going bad, heat is it worst friend.

When you say you adjusted your TPS to 90, I hope you mean .90 volts. How did you about adjusting it?

[hyper5oh]

try adj. the tps to .99 not .90 .98 would also be fine... try the o2 sensors if it was a long time sence those were replaced?!

[SVTcobra306]

Cleaning the MAF would be good too.

[mbliss_00]

Yeah it was .90, I heard that was the max you sould go. You have to dremel out the back screw hole a little and twist it while using a multimeter. The TPS sensor checks out fine. Could only get to one of the 02's, cleaned it with some carb cleaner, unplugged them both and it's still the same problem. I cleaned the MAF wires also, question is should they glow red when in operation??? Also set the timing to 14 deg. I'm stumped beyond belief!!!

[HiFlow5 0]

Try bringing you timing back to 10*, the stock setting. .99 volts is a little high. I would not go anything over .95 volts, there is no difference in performance from .95 to .99 volts. That is getting dangerously close to 1 volt, which then the ECU with have a fit.

[mbliss_00]

Don't really think that's the problem. More so a sensor or a stupid emissions part. Going to try to find an SBDS machine to help...

[mbliss_00]

Anyone? Anyone???