[SEG388]

Ok here's a another game. Figure out the problem. A :cookie: to whoever wins.

Ok...been going on for a little while. If low on fuel (3 gals) left which should still be plenty for it to run smooth the Dak starts hesitating and getting sluggish. Sometimes if it has even less but still like a gallon or two then it gets extremely sluggish to the point it barley moves. Sometimes, even with a lot fuller tank, it still hesitaes a bit here and there but generally runs a lot better. Maybe I shouldn't run in low first of all but I'm sure everyone has done it here and there. Only have done it here and there. However, that's besides the point. Even if low on fuel, it shouldn't do this.

The cat had to be replaced recently (broken up inside) so doubt that was ever it but if it was, guess it helped some. However, it's still doing it. I'm thinking clogged fuel filter? The check engine light does come on every once in a while though if driving for extended periods. That ain't often though. Far less since the Cat, EGR, and O2 was replaced. Yup, were all bad. My luck.

Needs to be smogged but wanna fix this first in case it's affecting the emissions which I am sure it is.:rant: Just wanna get some opinions before I start ripping her apart.

Thanks.

 

[6shooter]

sounds like fuel pump/filter. ive never done one on any of my daks, but my buddies 95 ram had a non-serviceable fuel filter, if i do recall. the whole assembly, pump and filter and everything, are down in the tank, so its a bit of a chore. some people, if they got the tools or a few extra buddies, just take the bed right off the truck to get at it instead of laying on your back to drop the fuel tank out. which wont come out from under your truck unless its way up on jack stands. and they're usually pretty expensive.

 

[Guest]

I saw this same problem several times when I owned my muffler shop, especially after a cat had broke up inside. Pieces of the cat would be blown back thru the exhaust pipe and get stuck in the muffler basically choking the exhaust off. When that happened, it was like riding around with the brakes on. Not saying this is defintely your problem, but may be something to consider.

 

[l1tech]

So if the check engine light is still coming on what is the code?? Has anyone bothered to do a fuel pump pressure and volume test or better yet checked the amp draw to the fuel pump?

 

[SEG388]

I saw this same problem several times when I owned my muffler shop, especially after a cat had broke up inside. Pieces of the cat would be blown back thru the exhaust pipe and get stuck in the muffler basically choking the exhaust off. When that happened, it was like riding around with the brakes on. Not saying this is defintely your problem, but may be something to consider.

Hmm...that does make sense. I'll have to check that out. Haven't got the engine code yet. I'm doing all of this Thursday and Friday at a Navy base. Got family down there and for about $ 3-5 (can't remember) you can rent a stall at the hobby shop for the day and they got loads of equipment there and lifts too, so that'll help. Oh, and if that's the case, the muffler would have to be replaced huh? No way to clean it out?

I'll let you guys know what happens. Thanks!

 

[Guest]

Hmm...that does make sense. I'll have to check that out. Haven't got the engine code yet. I'm doing all of this Thursday and Friday at a Navy base. Got family down there and for about $ 3-5 (can't remember) you can rent a stall at the hobby shop for the day and they got loads of equipment there and lifts too, so that'll help. Oh, and if that's the case, the muffler would have to be replaced huh? No way to clean it out?

I'll let you guys know what happens. Thanks!

Sorry, no way to clean it out. The cat crap gets clogged up inside the baffles in the muffler and kind of stops everything up. Before you replace the muffler, have someone rev the engine while you hold your hand a little ways from the tail pipe and see what kind of pressure you have. Another way to check it is to rev the engine and if seems like it's a little slow about revving up, then the exhaust pressure is building up inside the engine. It will rev up faster if the engine is cold than it will after it's been running for a while.

 

[Doom4life]

I had a similar problem on my '02 Dakota with the 4.7L engine. The symptoms I had occurred whenever the fuel gauge was showing 1/4 tank or less. Whenever I would try and floor it, the engine would rev up, but start hesitating and the RPM's would drop severely resulting in a weak ass attempt to accelerate.

It ended up being the fuel pump, and luckily it was still under warranty. At the time, I made it a bad habit of letting the fuel level get too low on a continuous basis and I think the fuel pump kept overheating and eventually got damaged.

I now make it a habit to always fill up before the low fuel light comes on as I'm sure this would have avoided the problem entirely.

 

[SEG388]

I had a similar problem on my '02 Dakota with the 4.7L engine. The symptoms I had occurred whenever the fuel gauge was showing 1/4 tank or less. Whenever I would try and floor it, the engine would rev up, but start hesitating and the RPM's would drop severely resulting in a weak ass attempt to accelerate.

It ended up being the fuel pump, and luckily it was still under warranty. At the time, I made it a bad habit of letting the fuel level get too low on a continuous basis and I think the fuel pump kept overheating and eventually got damaged.

I now make it a habit to always fill up before the low fuel light comes on as I'm sure this would have avoided the problem entirely.

I'm sure that's quite possible. But I am still leaning towards the muffler. Makes sense if the cat was broken up inside so likely the crap clogged it up. But, we'll find out for sure when I get it looked at this Thursday. Not gonna guess and just replace something. Bad idea. :jester: I'm having a buddy come along that knows this stuff too. So, he'll help me inspect it.

Thanks again for the pointers!

 

[SEG388]

Well in Lemoore right now with family. Sadly, couldn't get to her today haha but will tomorrow, place on base is open Fridays as well. Here's hoping it's just the muffler. I forgot to mention it backfires too when this happens so I am really thinking it is the muffler rather than the fuel pump. Find it hard to think a fuel pump/filter would do that but we'll find out.

 

[l1tech]

I forgot to mention it backfires too when this happens so I am really thinking it is the muffler rather than the fuel pump. Find it hard to think a fuel pump/filter would do that but we'll find out.

Don't count on it. You have the symptons of a lean running engine not that of an engine with a plugged exhaust.

Back in the day when cats still had pellets in them the plugged muffler was common when the cat let go. The cats today are of a honeycomb design and while they do break apart they usually stay in larger pieces that don't even get out of the exit of the cat, more often than not they just come loose form the inside of the cat and melt into one large chunk instead of breaking up.

Do yourself a favor and use an exhaust backpressure gauge to test the exhaust system for restriction. If you just try to feel for exhaust flow with your hand you won't have much luck.

 

[Guest]

Don't count on it. You have the symptons of a lean running engine not that of an engine with a plugged exhaust.

Back in the day when cats still had pellets in them the plugged muffler was common when the cat let go. The cats today are of a honeycomb design and while they do break apart they usually stay in larger pieces that don't even get out of the exit of the cat, more often than not they just come loose form the inside of the cat and melt into one large chunk instead of breaking up.

Do yourself a favor and use an exhaust backpressure gauge to test the exhaust system for restriction. If you just try to feel for exhaust flow with your hand you won't have much luck.

In '74 when the first cats became mandatory by the EPA, GM was the only and always has been, vehicle that had the pellets. Ford and Chrysler has always had the honeycomb ceramic guts inside from day one. Once a cat starts breaking up inside and the pieces start getting bounced around by the exhaust pressure, you would be surprised how large the chunks can be that make their way to the muffler. I've cut a lot of mufflers apart and found them to be packed tight with that crap.

Not saying this IS his problem, but a very good possibilty.

 

[caulk04]

I had to cut a cat out of a 94 Blazer...it broke apart and plugged the cat's exit. Nothing in the muffler. It was the honeycomb type.

This sounds nothing like an exhaust issue to me. Problem occurs more often with low fuel and is sporadic. If the cat junk was plugging something, it would be rather constant and likely not effect idle and low speed so much but it would struggle to gain RPM and get worse with more throttle.

 

[jnjinfla]

I know on my 92 there is two fuel filters. One inline on the drivers side framerail under the drivers door and another one on the fuel pump. When I removed the pump and replaced it the pump filter was packed full of crap. I never drove the truck before replacing the pump so I cannot tell you if I experienced the same symptoms. My guess is before pulling the pump replace the inline filter. If the problem goes away good! If not pull the pump and replace that filter. Just an idea.........

 

[ThisOldDak]

backfires are a fuel issue as far as I knew.

and unless you feel the exact same issue all the time, or atleast every time the engine/exhaust warms up, it's probably not the exhaust.

Just by reason of what you have explained it sounds like the fuel filter and/or pump is about done. Got 15 years of gunk in the tank, so when low on fuel it starts sucking more of it in. The light hesitation is probably because the filter is still mostly clogged all the time.

 

[SEG388]

Sure enough, it's something with EGR system. We didn't have the resources to really check it out. Gonna get it checked out at shop here for more info anyhow.

Always something...

 

[jnjinfla]

Sure enough, it's something with EGR system. We didn't have the resources to really check it out. Gonna get it checked out at shop here for more info anyhow.

Always something...

Tis the reason my egr system is completely removed. I just have the solenoid plugged in to avoid a code.

 

[l1tech]

What is making you think that it is something to do with the egr system. Only thing that really comes to mind with the egr would be if it is stuck open. If it were stuck open then you would have a very rough idle, if it idled at all, but as soon as you gave it gas the problem would be gone. AN egr system is so basic in it's operation yet people think it is this huge power robbing system. Most people don't realize that a properly functioning egr system has the ability to actually have the engine produce more power in some instances