Truck completely dying at WOT and kicking back on afterwards???

[jdyates]

Life span of a fuel pump you ask? Well that would be the amount of time between when the pump is made and when it stops pumping.

It honestly isn't something you can put a number on.

First, change your filter. I'm assuming since you haven't mentioned it, you haven't done it since you've owned it. After you change the filter, check the fuel pressure. Checking fuel pressure is the only way check that problem off of your list.
-Via Mobile-

I changed the fuel filter maybe two months ago max. The old one was full of crap, but really no difference between old and new.

 

[Mean Green]

You are going to want to check your fuel pressure. It wouldn't be a bad idea to pull the outlet line off of the fuel filter and let some gas run out into a drain pan and see if the gas is clean. If the old filter was really full of junk, it wouldn't be a bad idea to check the new filter and make sure it isn't full of rust or debris again if there is bad line or dirt in the tank. A fuel pump could very well be the issue, they will cause some strange issues when they are getting tired.

 

[jdyates]

You are going to want to check your fuel pressure. It wouldn't be a bad idea to pull the outlet line off of the fuel filter and let some gas run out into a drain pan and see if the gas is clean. If the old filter was really full of junk, it wouldn't be a bad idea to check the new filter and make sure it isn't full of rust or debris again if there is bad line or dirt in the tank. A fuel pump could very well be the issue, they will cause some strange issues when they are getting tired.

When i get some free time i'll bring her to the shop and test pressure. I have a feeling it's the pump. The old filter was in there for YEARS (a few rust spot on the outside, the nuts were borderline seized on), and there was no rust, just dirt.

 

[96-1500]

It wouldn't be a bad idea to pull the outlet line off of the fuel filter and let some gas run out into a drain pan and see if the gas is clean. If the old filter was really full of junk, it wouldn't be a bad idea to check the new filter and make sure it isn't full of rust or debris again if there is bad line or dirt in the tank.

^ x2. If the first one was full of gunk, it got in there for a reason. That reason is, there was gunk in the tank. Would definitely be a starting point to check.

I'll be interested to see what kind of fuel pressure you've got. If it's low and your lines/filter are in good shape...you know what the problem is.

 

[jdyates]

UPDATE: Found the problem.
The

Motherf*cking

Ignition

Coil.

My dad gave me the idea. He told me his Porsche (1983 944) had the same problem where it seemed like it just couldn't keep up at high revs, and that his ignition coil was bad. So I decided "what the hell, I'll replace one last part before I resort to the fuel pump." Low and behold, after looking at the old one, it was riveted onto the mount. I'm guessing original GM. An hour and $21 later, the problem is GONE. 100% running like a gotdamn champ. Haha. Occum's razor.

 

[bow61509]

glad to hear ya got her fixed man!

Sent from my static android

 

[jdyates]

glad to hear ya got her fixed man!

Sent from my static android

Thanks, man! It was killing me seeing my baby all sick. I'm gonna treat her by putting her little black dress back on. (Tinted lights).

 

[jdyates]

Dammit guys, I'm stumped. Every time i put a new part on it, the problem goes away, then comes right back full force after a few miles. Here is a list of what i have replaced so far:

-full TBI rebuilt, all gaskets and O-rings, injectors soaked in cleaner, new injector screens
-FPR rebuilt, new spring and diaphragm, pressure set to stock.
-new TPS
-new ignition coil

And i did a full tune-up recently as well. Plugs, wires, cap rotor, fuel filter, and the oil in the engine is fairly new (irrelevant, but noteworthy).

Here's what went down yesterday. I pulled the injectors, and noticed an O-ring MISSING, with little chunks of rubber around the TBI. Damn. Poured some cleaner through the injectors, re-installed them, and they completely clogged up. Tried to start her and gave her too much gas, and the high-pressure blew another O-ring and sent fuel EVERYWHERE. Not even a drop out of the injector bottoms. So i called my buddy to bring me some spare injectors and o-rings we had at the shop. Got her running again, but it still dies if i give her maybe 50% throttle. Nothing new.

What the hell is going on? I asked a buddy if it could be the fuel pump or timing, he said the timing shouldn't have to be adjusted, and if it was off, the Snap-on scanner would have picked up a misfire. And the TBI fuel pump should be at a constant pressure, so if it was going out, it would be dying at idle as well, which it doesn't.

I'm stumped. Any ideas?

 

[bow61509]

you seriously might go ahead and check the timing it's easy and the timing chains are known to stretch also have you replaced the little ignition module under the dist cap? I can't think.of what it's called but they are cheap and are known to cause alot of problems, usually they quit altogether but sometimes they can cause problems. that's all I can think of man



Sent from my static android

 

[bambam78]

Just gonna throw this out there because my truck was doing about the same thing, when your truck warms up, unplug your CTS on your intake, and see if it doesn't fix your problem, if it does its your fuel pump

i found that when i uplugged the cts it'd smooth out after it warmed up, (thought i had a bad cts sensor or connection) and you could drive it anywhere, turns out my fuel pump was getting weak, and unplugging the cts was making the computer send more gas, making it run better lol