Help needed: Hesitation Problem

Tony Montana · Feb 27, 2007

Hey guys,

I have been having a problem with my car hesitating while cold ever since I got it.

The car has 88000 miles. the problem occurs, first thing in the morning when the car is cold. I will let it warm up a bit (sometimes not) either way, when i press the gas, it bogs and kinda feels like it cuts out for a couple of seconds. Like it isnt getting fuel. After driving and accelerating it is normal for the rest of the day.

I have done a full tune up, plugs, wires, cap rotor, fuel filter etc. I recently cleaned the maf as well. the problem is still occuring, i think my fuel pump might be on its way out?

Any other suggestions opinions would be appreciated.

purplehaze · Feb 27, 2007

i have that exaect same problem, and did everything you did. still have my problem.

ryclef331 · Feb 27, 2007

Its not your fuel pump. It sounds like your car is having a problem while its in closed loop mode (i.e reading from all the sensors).

You need to verify all your sensors are in good working order. You've cleaned the maf. Thats the first step. Now, check the TPS voltage. Should be .96-.99v key on/engine off. I'd also look into a new coolant temp sensor (there are two of them...you want to replace the one on the passenger side screw into the heater tubing. This is the one for the ECU) and an air inlet temp sensor. They are cheap but can wreak HAVOC on tuning issues. How old are your O2 sensors? Try popping them out and LIGHTLY cleaning them off with a wire brush. Its a sensor issue somewhere causing the car to not "warm" up properly. What is your MAF / Cold Air Intake setup?

Tony Montana · Feb 27, 2007

ryclef331 said:
Its not your fuel pump. It sounds like your car is having a problem while its in closed loop mode (i.e reading from all the sensors).

You need to verify all your sensors are in good working order. You've cleaned the maf. Thats the first step. Now, check the TPS voltage. Should be .96-.99v key on/engine off. I'd also look into a new coolant temp sensor (there are two of them...you want to replace the one on the passenger side screw into the heater tubing. This is the one for the ECU) and an air inlet temp sensor. They are cheap but can wreak HAVOC on tuning issues. How old are your O2 sensors? Try popping them out and LIGHTLY cleaning them off with a wire brush. Its a sensor issue somewhere causing the car to not "warm" up properly. What is your MAF / Cold Air Intake setup?

I need to check TPS
Coolant temp sensor hasnt been replaced
Im pretty sure my o2s are original, (gonna replace them soon asi can, as gas mileage isnt the best)
I have a stock air inlet(i had a bbk cold air but had the same issue)

I think it maybe the o2's

Im gonna check this stuff thanks for the help

97blackgt · Feb 27, 2007

you should make a trip to ford and have them pull some codes and look at live data

ryclef331 · Feb 27, 2007

the only thing ford could do that he can't do himself is monitor the sensors while the car is running. You can pull codes yourself with just a test light and a piece of wire. Not worth the money.