Question: Low speed drivability

[jcorey408]

I have had the clutch slave and clutch cylinder both replaced. I have had the rear brakes replaced. I have had the shifting linkage lubed. There is still hesitation and vibration off the line, the car really struggles and I have to give it way more clutch than I should.


I have read on many forums that replacing the in tank fuel pump fixes a lot of supposed gremlins. Many people have used the tpi pumps for the crossfire with success. I found the following link through one of these forum posts.


Racetronix - C469 Fuel Pump Assembly, Factory Upgrade - Kit Configuration Page


Let me know what you guys think, I appreciate any and all help.

 

[muddywaters]

How about the clutch itself???

 

[jcorey408]

The clutch is supposedly just fine. Or so says the shop I took it to. And I doubt they would skip an opportunity to charge me more money. :L

 

[boomdriver]

I have had the clutch slave and clutch cylinder both replaced. I have had the rear brakes replaced. I have had the shifting linkage lubed. There is still hesitation and vibration off the line, the car really struggles and I have to give it way more clutch than I should.


I have read on many forums that replacing the in tank fuel pump fixes a lot of supposed gremlins. Many people have used the tpi pumps for the crossfire with success. I found the following link through one of these forum posts.


Racetronix - C469 Fuel Pump Assembly, Factory Upgrade - Kit Configuration Page


Let me know what you guys think, I appreciate any and all help.

Have you done all the appropiate test?

By struggle, I assume that you mean it lacks the power to pull away from a standstill?

"using wayore clutch..." Does that mean you have to 'feather the clutch' or slip the clutch to get it rolling?

Is this a 4+3 being driven in high range?
IIRC the 4+3 bottom gear was so low that you could start the car in gear and it would creep along without using the gas pedal.....If your engine won;t pull that gear.....somethins wayyyyyyy wrong. Something more than fuel GPM. A bigger fuel pump won;t do much for low rpm run problems. ALL the bigger pump does is to supply enough fuel at higher so it can maintain 15 psi of tension on the fuel system at high rpm. How fast it gets used is the job of the injectors. The CFI system only needs 15 psi...pretty easy to provide. It CAN use more GPM at high rpm though...

Throwing parts at problems usually does not solve the problem. Discovering what the problem really IS and then approaching it with the correct parts (if needed) and the correct adjustments is the proper way to get the car to run right.

Test the fuel system and follow the trouble tree charts in the FSM. That will lead you to the only possible solution to your problem. The cost of a FSM is 10% of what you will spend just buying parts without a clear diagnosis.

 

[jcorey408]

Decided to go with an 85 to 87 intake pump, replace seal on rear fuel door, a new chip, replace iac, tps, have the throttle bodies reworked by Dynamic Crossfire Solutions. Not sure yet if I am going to bore the tb's yet or not as I am not sure if I want to wait on a Renegade manifold or not. Would I have to bore the intake though to match the new throttle body bore?

Also, how do you run the tb's in parallel? I know this is a lot of things to throw at the car at once but I am okay with that. I want to see how the Crossfire should drive not how it does currently.