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Car bogs down above 15% throttle??? Fuel Pump?

timboku

timboku

New member
Car bogs down when you give it gas while in drive. If I keep throttle under 15% it runs fine. Give it some gas and it bogs down and is very sluggish. When the car is in nuetral or park you can rev it and it runs fine. No SES light on or anything. New plugs, wires, and O2 sensor recently installed. I think fuel pump is original and it has over 200k on it so that whay I am thinking. Thoughts before I get a new one??
Fuel Trims are fine at idle but when you gas it they go crazy as well.
 


Only way to really tell is to hook up a pressure gauge, tape it to the windshield, and take a drive to make sure the pressure stays where it should. Could be a few other things as well but I think you may be on the right path on a fuel issue whether it be the pump or regulator. Could always pull the vacuum line on the FPR and see if it smells like gas as a super quick check. Could be leaking past and bogging it with too much gas (very bad)

Also just read what scotty said, I just have a question as I really don't know, if the cat is clogged wouldn't that make it hard to rev in park and neutral too?
 
No cat installed so thats not it. Pulled FPR already no smell. Its just weired that it does not bog down or stumble in park. Just under a load. Do they rent fuel pressure testers??? No CES light on or flashing either.
 
also, what pressure should the pump be at idle and under load? Also, whats a good pump? Was looking at the zzp one for 100 bucks.
 


I think 45 psi at idle is good. Key on engine off should be the same and stay there, and not drop off. Not sure about under load, probably still in that area.
 
So turned car around to back it in to garage figured I would change the fuel filter just to make rule that out. I hit the schraeder valve on the fuel rail to release the presure and a baby drop came out not under pressure. Bad sign right that should be under pressure so thinking its the pump even more now.
 
try again with the key to run,car off. if nothing comes out the pump could be bad.

what year you have? the high speed relay trick may work. if its got a bad resistor. 97-01 that trick works fot iirc.
 
02 gtp...only single stage pump....it starts right up no problem. Gonna change filter now and see what that does.
 
buy a pump while your there getting the filter. if the filter clogged to the point the pump stopped, it killed the pump probably.

do you hear the [ump whine at all when the key is first turned to run?

and then theres my fav. bang on the tank bottom with your palm a few times, this can shock it back to life sometimes. if it fires up and runs well the pump is bad

if it comes down to a new pump, look on line for just a replacement pump, you take your old one out of the sender bucket and install the new one. it comes with a new sock filter hose zip ties and a plug sometimes to power it.

just replacing the pump is like 30 bucks or less. whole bucket with sender and new pump up to 300.00.
 


I have high flow filter from zzp that i will put in. The pump works the car starts and drives no problems. It is when you give it over 20% throttle it bogs down. Who sells the walbro pumps? I have 42lb injectors and a rewire kit to put in so looking for a good pump to go along with it.
 
Ordered my pump which will be changed out. But any thoughts of this being a MAF issue? When i unplug the maf it doest really change how the car drives. Trims are perfect though and no CES light. gonna try to locate one in the garage and swap them?
 


Well, the MAF being bad isn't going to cause 0 fuel pressure at the rails. If you have next to no fuel going to the engine, unplugging the MAF isn't going to make a lick of difference, cause the PCM cant get more fuel to the motor.
 
I have pressure at the rail when its running. I still need to the store and rent one to check and i will regaurdless be changing the pump as it has 200k on it already. Its just weried that it runs perfect when you dont go above quarter throttle.
 
Quick update...So changed pump and that helped alot..there is pressure in the lines and starts right up now! but still was sluggish in higher rpms...changed maf..no change..finally changed coil pack module and bingo all fixed..runs sweet....fuel pump rewire tomorrow.

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