Acceleration problem - Not gaining speed (1 Viewer)

[mydogsmonkey]

Hi all, I have an interesting issue that perhaps you guys can solve easier than I can just randomly replacing parts.

Its an intermitttent problem that occurs when I press the accelerator down. I can press on the accelerator at a position that normally would cause me to slowly gain speed, but it feells like the fuel is cutting out a bit and will instead keep me at the same RPM and not gain speed. This occurs at high rpm, low rpm, full throttle, half throttle. Any ideas? I'm trying to avoid completely replacing every part in the fuel system as I have limited time for Turf N Surf this coming weekend.

 

[john nannemann]

throttle position sensor maybe

 

[mydogsmonkey]

I'm currently thinking TPS seems unlikely. Fuel mileage appears to be the same as its been, and no CEL. Good suggestion though. Is there a way to check for sure its bad other than to replace with a known good one?

 

[bajaphile]

Have you looked into it being the in-tank fuel sock ?

 

[mydogsmonkey]

Have you looked into it being the in-tank fuel sock ?

seems like its a possisble culprit. I may try to open it up Monday if I have a chance and take a look, being that I suspect the fuel pump anyway. Anyone have an idea for how to test the fuel pump? Just run straight 12V to see if its a constant flow of gas?

 

[bajaphile]

From factory service manual...

 

[tominboise]

How long since the fuel filter under the manifold has been replaced?

You can pull the return line off the fuel rail and see if there is fuel there. If there is, it's an easy way to eliminate everything upstream from the rail.

 

[mydogsmonkey]

fuel filter under the manifold has never been replaced but it seems doubtful. If it were constantly surging at full throttle and giving me an intermitten issue at half or normal use, I would likely suspect the fuel filter but it seems like it should be something else. The fuel pump appears to be in spec with impedence, the inside of the gas tank looked clean and the fuel sock looked to be in good shape.

 

[tominboise]

Have the injectors ever been out and serviced?

 

[mydogsmonkey]

Have the injectors ever been out and serviced?

No. what reason would make the injectors a likely culprit?

 

[how900]

I have been chasing a running problem for about two years, it felt like a fuel problem, replaced fuel pump, TPS, fuel filter, distributor cap and leads..... didn't think it was electrical but they looked old.....plugs.....maf, air intake pipe, air filter, .....finally the o2 sensor fixed the problem, ....I had checked the ohms reading on the o2 sensor about a year ago, .....it seemed to be giving correct reading from cold and as the engine warmed up, but it's was the problem........my car was miserable some morning,....worse if it had stood a week or 2 without being used, .....o2 sensor was making it run lean, sometimes it would kick down but had no power due to how lean the o2 sensor was making the engine run,,,,,,, fuel consumption has got a bit worse but the power is back, it drives like a different car now.

 

[jonheld]

First thing I would do is reset the ECU by removing the 15 amp EFI fuse in the fuse box under the bonnet for about 10 minutes.
That will clear any stored codes and force the ECU to relearn all of the sensors.
I don't understand your reluctance to change out a 20 year old fuel filter. That sure seems like it would be prudent on all accounts, but it's not my truck. You had the fuel pump assembly out and didn't replace the pre-filter while it was all apart. That makes no sense to me either.

 

[mydogsmonkey]

First thing I would do is reset the ECU by removing the 15 amp EFI fuse in the fuse box under the bonnet for about 10 minutes.
That will clear any stored codes and force the ECU to relearn all of the sensors.
I don't understand your reluctance to change out a 20 year old fuel filter. That sure seems like it would be prudent on all accounts, but it's not my truck. You had the fuel pump assembly out and didn't replace the pre-filter while it was all apart. That makes no sense to me either.

Because the prefilter sock is clearly not the problem and i dont have 2 weeks to leave the car apart as there is a trip coming this weekend. id rather fix the problem now and tackle maintenance at some later time. i just dont have the hours to waste replacing a fuel filter that is likely not the culprit. ill tackle PM after January with all my major trips out of the way.

 

[mydogsmonkey]

First thing I would do is reset the ECU by removing the 15 amp EFI fuse in the fuse box under the bonnet for about 10 minutes.
That will clear any stored codes and force the ECU to relearn all of the sensors.
I don't understand your reluctance to change out a 20 year old fuel filter. That sure seems like it would be prudent on all accounts, but it's not my truck. You had the fuel pump assembly out and didn't replace the pre-filter while it was all apart. That makes no sense to me either.

My previous reply plus previous info from toyota claiming its a lifelong part, with an extremely clean gas tank, and prefilter sock lead me to believe its likely not the fuel filter.

 

[FJP971]

I'm not sure how many miles you have on your rig and I'm not sure what Mr. T was estimating as a lifetime of mileage but a filter change is a good start. I changed mine recently with just under 200k and it was dirty. May not fix your problem but then again it might. It's not as difficult as some make it out to be.

 

[richardlillard1]

Why is it that every time these threads pop up, people suggest fuel filters, then the poor sap swaps one, only to comment that it made no change?

And yet, here we are.

 

[mydogsmonkey]

I'm not sure how many miles you have on your rig and I'm not sure what Mr. T was estimating as a lifetime of mileage but a filter change is a good start. I changed mine recently with just under 200k and it was dirty. May not fix your problem but then again it might. It's not as difficult as some make it out to be.

How many hours would you estimate with two 3ish banana cruiserheads?

 

[mydogsmonkey]

Why is it that every time these threads pop up, people suggest fuel filters, then the poor sap swaps one, only to comment that it made no change?

And yet, here we are.

I swapped none. im on a time crunch and trying to determine if that investment of tine will net me the fix given the limited amount of time i have between now and friday. i realisticly have 3 nights to work on this.

 

[mydogsmonkey]

Im under the assumption that if the fuel filter is clogged I would see more surging issues under Full Throttle. I am experiencing surging issues at all Throttle positions regardless of the gas demand

 

[FJP971]

Why is it that every time these threads pop up, people suggest fuel filters, then the poor sap swaps one, only to comment that it made no change?

And yet, here we are.

I stated that it may or may NOT fix the issue but it is a fairly easy thing to do and it should be done with regular maintenance anyway.

How many hours would you estimate with two 3ish banana cruiserheads?

It took me about an hour or so. Remove the tire and plastic covers and access is not so bad. Fuel Filter Replacement
How the &^%$& do you change the fuel filter?