Contour Enthusiasts Group Archives Forums General Troubleshooting 2.5L cold hesitation prob

Gentelmen (and ladies if aplies),
I have been reading the posts for several months since I bought my 1995 SE ford contour. The information is great, I have learned a lot and found a new hobby. Lets get the basics out of the way:
2.5L, automatic tran. Following parts new: tires, brakes, rotors, calipers, starter, EGR valve, IAC valve , EGR vacume regulator, MAF sensor, fuel filter, 90% of vacume lines (accesable in engine bay), upper and lower intakes cleaned with new gaskets (torqued with my new torque wrench), O2 sensors, fuel injectors sent out of state for bench testing and ultrasonic cleaning, spark plug wires, motorcraft platinum plugs, fuel pressure regulator, high flow air intake (from BAT motorsports), new fuel charging wiring harness (over $500 from dealership), fuel pump changed three weeks ago, and coil pack.
Ok, to the problem. I live in Phoenix so it dosen't get to cold. But the car is very hesitant if the engine is not at operating temp. It dosen't stall but acts like it wants to. With the new air intake on I can also hear a slight popping while the engine is hesitating. Once warmed up the engine pulls strong at WOT, but while cruising at high speed I can feel a slight miss in the engine. Now the new fuel pump is makeing what seems like an unusualy lound (and not steady nois) from under the back seat. Again, I have a shop manual and am learning but I believe I installed it correctly. I am running out of possible causes. Any possible suggestions would be appreciated.
Adam

Welcome to CEG!

Have you checked for codes?


Test fuel pressure at idle and under load.

Test or replace the TPS.

Check operation of the secondaries. On a 95 they should both rotate 90 degrees when the engine is started.

Check operation of EGR system.

Check operation of PCV system, and double check the rubber elbow from PCV valve to UIM.

Test or replace the ECT.

Make sure wires are snapped onto the plugs.


The usual stuff!

Welcome .

Thanks for the great info! I will try some of these ideas next weekend. I have to put the cylinder head back on my other car before taking the contour out of comission again.

"I can also hear a slight popping while the engine is hesitating"

I've been having what sounds to be a very similar problem with my '95 SE.

What struck me what the part you mentioned about the popping noises! I have no idea what the noises are or what's causing them....but I'll be monitoring your progress CAREFULLY since you seem to be way more on top of the situation than me.

Chris

I believe I had fuel burning in the intake manifold, making a popping sound. It was very aparrent because I have an open-element filter that doesn't muffle the sound much.