Me thinks it's time for a new truck... Seems like no matter what you do that one single issue seems to come out on top everytime...

 

Yeah kinda seems that way doesnt it. The truck had many issues when I first started on it months ago. This bogging down the minute the butterfly opens was just one of them. As it was way overdue for any sort of maint and did have vaccum leaks, as well as many sensors that were bad, I figured one of those fixes might also fix this one. All other problems have been fixed but this one still exists.


Ive replaced All items that in any way should be causing such a problem....should be....obviously I'm missing or have overlooked something....something that is way out of the norm.


If it had terrible compression issues, or did not run as great as it does (when it does do so) I would have abandoned it long ago.

 

Just for ****s n giggles have you tested the pressure coming out of the exhaust? We know you've tried everything other than buying a new engine but if it's fluttering your compression gauge may be faulty. Hold a piece of paper about 1/2" away from the pipe and see hat it does.

 

I'm game.

Aside from the fact I removed the cat to check for clogging there, Ive also ran it with no exhaust same issue. Piece of paper on the tailpipe shows a good steady flow.

As for pressure readings Ive use 2 separate compression gauges and 2 separate fuel pressure gauges. MY older craftsman gauges and my newer Snap-on gauges.

 

I seem to be at the same crossroad. My truck will drive around the farm all day with no issues, but get it on the road and it dies when going fast. Arkansas truck with faded paint and no rust....a shame

 

I read through this post, but I did not see where you were checking fuel pressure under a load.
I think dodge would be the same as chevy on this, but with a chevy, if the pressure is 45 at idle, under a load it will go up a little 48-50 psi. It should never go down.

 

Well, in the case of mine...when I first started working on it it would die every time you stopped (along with other issues). Ends out that was a major vaccum leak which has been fixed. As for now no it will not die at all, idles great, and will go down the road fair, but when you step on the gas just bogs down the second the throttle body butterfly begins to open. Eventually if gently pushing it will take off as it should. If you push down on the throttle heavy, it just bogs down like losing fuel or way too much air, but all fuel system checks show great psi on the fuel system either idling or revved up. New injectors and repaird ecm show good injector cycling. And no vacuum leaks.
Very frustrating to troubleshoot.

 

revving up is not enough. run a fuel pressure guage out the back of the hood and tape it to the windshield. Test it under a load going down the road. If it is 45 at idle, it should not drop. If anything it will increase a few lbs. under a load.

 

He just said it... right there... can you see it?...

 

Suzonda, thanks.


Maybe my reply to 93ragtop was a bad choice of words at the moment. Revving up I meant when running, not just goosing the the throttle while sitting still. I have run it more than once down the road, with a fuel PSI guage installed at the testing "T" on teh injector fuel rail. (Ive tried using both of my guages craftsman/Snapon to eliminate bad guage theory). Whether at idle, goosing sitting still, or full throttle at 70 mph, it holds a pretty consistent 40-42 psi. Now mind you, when I say full throttle, I do not get a full throttle response back from teh engine, instead it just bogs down like it running out of fuel or some other issue.


This bogging/lack of acceleration happens even at the most basic slow opening of the butterfly, but if you gently ease it through sometimes it revs up just fine. If you just all of a sudden push it down hard all you get is a deep gulp of nothing often followed by a slight backfire....but all this going on it never dies it just goes back to a nice normal idle once butterfly is released.