Contour Enthusiasts Group Archives Forums General Troubleshooting Problem on acceleration

Hi,

I have a really irritating problem that has happened to me a few times recently. While accelerating I have had my 2000 SVT sort of stall out until I let off the accelerator comletely. If I try to accelerate too hard after that for a few seconds it will do it again. If I don't give it to much gas for a few seconds it will be fine and I can accelerate like normal. It only seems to happen above 4000 RPM but never at the same level twice. It has happened to me both on the highway while trying to pass somone (embarrassing) and while accelerating from a stop. The incident on the highway actually forced me to pull over due to the fact I was on a hill and it was difficult to keep my speed without giving it the required gas even after gearing down. Again, after giving it a few seconds it seemed fine. I took it to a local shop and they plugged it into thier computer and found only a fuel rail pressure sensor error and replaced it. It seemed to be okay for a day or two, but just yesterday it did it again. I hesitate to take it back to the shop as they had to look hard to even find the sensor problem. Any ideas?

Also, I am not sure if it is related, but as long as I have had the car there is always a hesitation in the RPM band between 3000 and 4000 RPM. Acceleration up to and after that point is great.

Thanks in advance,
Jim

Welcome to CEG!

Hesitation between 3000 and 4000 rpm stands a good chance of being your IMRC. The IMRC box or cable may cause the problem, or crud buildup around the secondary butterflies may be causing them to stick.

Total power loss or bucking on accel is often the fuel pump (if not filter). No gas pressure = no power. This happens of course when fuel demand is highest.

A search on IMRC and fuel pump will turn up loads.

My 2000 CSVT is having a similiar problem. As I approach 5,000 rpms under full throttle, there is a significant power loss. I suspect a dirty fuel filter, so I will change it and let everyone know if it helps.

TR

I left out a little bit of information. On a recommendation of a mechanic friend, I changed the fuel filter. No difference after doing that. Also, when I am having the problem, the car will jolt back and forth. This might support what you are saying about the fuel pump. Maybe under high load, the pump is failing. Another observation I have has is that this most often happens when I have less than a quarter of a tank of gas. Thanks for the ideas so far.

Jim

I second the fuel pump suspicion - the signature is to have the problem pronounced with less than 1/4 tank of gas.

Fuel pump problems on these cars are not unheard of...

I remember finding someone's website through these forums with detailed instructions & pics on FP replacement. It's not necessary to drop the fuel tank, the assembly is accessible by removing the rear seat cushion.

Tiv

i'll put money on it being the imrc. Next time it happens, pull over and see if the secondaries are opening. I just had to buy a new IMRC for my car.. it was $130 from the dealer and I installed it myself rather easily.

Check your maf, mine was shutting down when she got hot, had to change mine and car works okay.

I have had the problem in multiple situations, ranging from from just starting the car (cold) to it happening after I have been driving the car for more than 100 miles.

I will check out my options on both the fuel pump and IMRC. I will report back with what I find.

Thanks for the help,
Jim

Well, turns out it WAS the fuel pump. I had it fixed today and it seems much better. An OEM fuel pump was around $285 from Ford and then $150 in labor for them to drop the tank, replace the pump and do any necessary testing. Thanks for the help with this, I think it took less time to get this fixed since I mentioned to the mechanic that I suspected the fuel pump (with the help of this forum). My next task to to fix the throttle hang issue, but I think I can handle that one on my time rather than the mechanics.

Thanks again,
Jim