I have a 2002 GMC D\A with 53000 miles. Under hard acceleration, at the end of 4th gear, around 70-75 mph, 2800 plus rpm's, it starts spuppering or like a hard mis. The egt's will jump very fast from 1100 to 1300.

It does it with the juice or without. It will repeat this almost at will. Any help would be appreciated.

:help:

Injector? (s)?

Ben

hmmmmm. I though it was just an edge thing. maybe so injectors, heh?

Have you changed your fuel filter lately?
How's the temp's there, any chance of the fuel gelling and restricting fuel flow thru the filter?

Temps are in the 60's. I have about 18000 miles on my primary fuel filter and a secondary post racor. But if it was the fuel filter, why wouldn't it starve for fuel all the time?

Could this be a sign of injector failure?:confused:

Mine did the same thing without mods. And come to find out it was the injectors.

It could be a leaky or sticky injector thats screwing up timing and effective injection length. That would explain the jump in temps.

I would change the fuel filter and see what happens. I think you'll be surprised.

Temps are in the 60's. I have about 18000 miles on my primary fuel filter and a secondary post racor. But if it was the fuel filter, why wouldn't it starve for fuel all the time?

Could this be a sign of injector failure?:confused: You have 18000 miles on your fuel filter? Change it first before you get to worried about anything else.:grd:

check for fuel in the oil, if none found, change the filter and run an lubricating additive. well thats what would do.....

Ya with 18,000 miles on your factory filter which is a primary according to your post, there's a good chance it's partially plugged, espically if the fuel in your area is not that good.

The reason it dosen't starve all the time is that the greatest demand for fuel is in the upper rpm's with a big load on the engine, like in a upper gear.
Lower rpm's and loads = less fuel needed

So your filter may just be starting to get clogged but would eventually start to effect lower rpm operation as well.

Same thing happen's in winter time with waxing of the filter, enuf fuel might get thru the filter to idle and maybe drive the truck slowly but when you try to get a larger quanity of fuel to speed up the truck or pull a hill it just won't go.

So as others have said start by replacing the factory filter, cut open the old one to see what it looks like inside, if the pleats are all black then it was clogged. Also change your Racor and cut it open to see what that looks like inside so you will have a refrence for your next filter change's .

2 factory filter change's = 1 Racor change Maybe.

:grd:

Good Luck.

DD

Thanks guys, I'll change them both this weekend and get back to you.

Changed both filters yesterday. The factory filter was black as coal, 100%. The post Racor was 30% dark, I would guess. I can definately say the post filter is good, I just hope that it doesn't prolong my injector life to say 205000 miles.

Truck runs great.....

Thanks all.