Hesitation Problem Help

[foxconv]

I own a 89 convertible Foxbody mustang. It runs good most days but sometomes its starts to have a really bad hesitation. It hesitates so bad that you can't drive it. Also it usually occurs around 2500 to 3000 rpm. When it hesitates, the rpm starts flickering like crazy and you can't accelerate past 3000rpm. Details about the car is that it is bone stock. 302HO. No check engine light. Just airbag light is on.

 

[Boosted92LX]

I own a 89 convertible Foxbody mustang. It runs good most days but sometomes its starts to have a really bad hesitation. It hesitates so bad that you can't drive it. Also it usually occurs around 2500 to 3000 rpm. When it hesitates, the rpm starts flickering like crazy and you can't accelerate past 3000rpm. Details about the car is that it is bone stock. 302HO. No check engine light. Just airbag light is on.

I'm not positive, but I don't think 89 cars had a check engine light, newer cars do.. Or was that 87???? You need to check for codes anyway, I'd say.

 

[foxconv]

I'm not positive, but I don't think 89 cars had a check engine light, newer cars do.. Or was that 87???? You need to check for codes anyway, I'd say.

I already checked for codes with a obd1 scanner and no codes came up. Only thing right now is that the airbag light keeps flashing.

 

[A5literMan]

I already checked for codes with a obd1 scanner and no codes came up. Only thing right now is that the airbag light keeps flashing.

No codes or a code 11? More than likely a sensor issue. But could be other things like ignition, gas,vacuum leak,etc. have you recently had any work done to the car? Also this should be in tech not talk?

 

[jrichker]

No code 11 (two flashes when the computer dumps the codes)? A perfectly functioning system will always get a code 11, it is the everything is OK code. The 11 code is computer passed its internal self test.
If you don't get an 11, you have computer or wiring problems.
Please check and repost.

 

[foxconv]

Yeah I got a code 11.

 

[foxconv]

I just did the jumper method and it gave me that code.

 

[A5literMan]

Do you have good spark? What kind of condition are the wires,plugs,cap,rotor,and coil? I'd start there.

 

[foxconv]

I got a new distributor but old wires and spark plugs but they look in ok condition. Most the time the mustang runs fine but some days for no reason when I start it and try to go for a cruise, it starts hesitating really bad to the extend that you can't drive it. Then the next day I start it up and its all fine.

 

[A5literMan]

What brand of distributor?
@jrichker could this be the pip sensor?

 

[jrichker]

Does the problem seem to appear only after the engine has warmed up?

 

[Boosted92LX]

TFI?

 

[foxconv]

I got a brand new distrubitor, tfi, pip. The hesitation occurs even if the car is cold. Can it be a bad fuel pump or regulator?

 

[foxconv]

Also realized there is some oil leaking out from the side where the heads meet the block. Bad gasket im assuming. That can't be the cause of the hesitation because if it was, it would occur all the time.

 

[A5literMan]

I got a brand new distrubitor, tfi, pip. The hesitation occurs even if the car is cold. Can it be a bad fuel pump or regulator?

Put a gauge on the regulator and see what pressure you have. It could be the pump or regulator or filter or...?

 

[mikestang63]

didnt know 89 was an airbag car.

 

[A5literMan]

didnt know 89 was an airbag car.

Mine wasn't

 

[foxconv]

Mine does. It has a later model looking steering wheel. Ill check again if its a 89.

 

[foxconv]

Oops it was a 91. Got it confused with my other mustang I sold. It shouldn't matter though.

 

[mikestang63]

Oops it was a 91. Got it confused with my other mustang I sold. It shouldn't matter though.

it actually does- of you had an airbag light going off in an 89 then someone had changed the harnesses and gauges,- 89 and 90 engine harnesses are different.

carry on