Hey guys, got a question. Durind acceleration, my truck had a lot of power and feels real strong if I only give it 1/4 to 1/2 throttle. Whenever I give it more than that, it feels like it has lots its power. And the exhaust sounds almost like a v8 gas motor not running on all cylinders. The acceleration is very sluggish. It really feels like the motor isn't being fueled enough. Anyone ever experience this, if so what fixed the problem. I may add that I have:
TS 6 position chip
banks quick spool housing
banks downpipe
K&N open element air filter kit
10k mod
No Cat
4" exhaust
E4od w trans command

 

sounds like the same thing my truck did at one time, put a feul pressure gauge on the scrader valve see what the pressure is at idle, then drive the truck with the gauge and see if it drops if so needs a fuel pump, my truck had 65lbs at idle but when i drove it ,it drop to 15lbs

 

A little experiment for you. Set the cruise control up around 85-90 mph then tap the brakes to disengage it. Now let it drift down to 55 or so and hit the resume botton. Is it sluggish returning to speed or run like a scalded dog?

 

Hey actually, thats interesting? Where are you going with that, because I never would have thought to check that. I will try it tomorrow and let you know what I find.

 

If when you reapply the cruise it takes off harder that it does when you mash the pedal manually, your problem may be the output voltage of your throttle position switch.

 

Okay guys, it seems to be an intermittent thing. As far as the cruise control theory, it seems to act the same as always. Now sometimes, depending on your speed. when you stomp on it, it will run pretty good. But for the most part, it's seeming underfueled. Almost like a V8 running lean. What should my fuel pressure be at? Ok, picture taking off very midly, and the truck running like a bat out of hell, but when you mash it, you cann actually feel the power crap out on you. It's kind of embarrasing actually! hahaha

 

vwman80,

I am having a very similar problem. My mechanic has changed my fuel pump and injector pressure regulator as well as removed the fuel tank and cleaned the screens. At this point, the truck will idle fine and run at low speeds pretty well, however when you "mash on it" it begins to miss and looses power to the point of almost stopping. Mechanic put pressure gauage on to check fuel pressure and pressure drops way down on acceleration. He now thinks that the new fuel pump is defective and is going to replace it a second time. I will let you know if this helps.

Does anyone know any other reason this drop in pressure could be occuring?

Thanks,
bigvic

 

did you ever get the problem fixed, what was it?

 

How about you?

 

The only thing that seems to affect the problem is my oil. I run Rotella 15w40 and change it no later than 5000 miles. Every time I change the oil its like a new beast. Obviously the injectors really like fresh thick oil. But every once in a while its still a terd on acceleration. I wonder if it could have to do with converter stall??? anyone???

 

Could be injector o-rings. have you ever had them changed? how many miles on the truck.

To test the o-rings witht he truck in park rev it to the redline quickly. does it hesitate or smoke at all? if it does you probably need o-rings. if it smoothly and quickly goes to redline then it not o-rings.

 

Ok Tim, I would like some thoughts on this one... Getting ready to replace my fuel pump because of a leak... But first I had to go to DEQ and get tested... So I re-programmed the EDGE to stock... and went to test... when the asked me to accelerate FAST she took off to about 2300 rpm and then was VERY sluggish to the 3k mark and then seemed fine, she never got better! Could be the fuel pump right? I don't want to do O Rings yet cause I want Stage 1's and the TW chip.... Just checking with the pro's to get a concensus...

 

I agree with Cookie88-check your throttle position voltage- If you are going out of range at WOT it could be as simple as an adjustment. Too easy to fix it, you should verify it before you spend any big $$. Is there any chance that it is defueling due to a faulty boost reading or MAP sensor, or from a plugged or malfunctioning EBP sensor?

 

This is interesting,when I read this I too went outside and tried to rev my truck,it also reved to 2300rpm or so ,sputtered a bit then jumped up to 3200 or so rpm,I did this 2or3 times same thing every time and no smoke out the pipe,so I checked my oil it,s ok,but I noticed fuel under the fuel pump GREAT,I started it again and did the same thing but this time I eased the fuel pedal and it went to 3200rpm no problem so Im thinking fuel pump is on it,s way out

 

To both WALJON and Mcdavidson from what Coon says that a symptom of bad o-rings many times. I have not used that test and replaced the o-rings to verify its the cause but its very possible. Best way to check the fuel pressure is to do the same thing with a fuel pressure gauge installed to make sure fuel pressure doesn't drop too far.