Okay. I've asked this in there multipul times, and its the same crap over and over again, and my fuel issue never gets solved.

Truck is having a hard time figuring out how much fuel to dump, and its giving me a bad idle.
The FPR controlls this, but the FPR is new, and it shouldn't be a vacuum issue. I have lots of vacuum. I wish things were more electronic then vacuum controlled.
Anyways.
I've replaced everything that has to do with the fuel delivery numbers and I've had no luck getting this idle down problem solved.

You basically let off the pedal and it will stay idling high in neutral, then it will eventually rev down. If it was a vacuum issue, I would think it would be to much vacuum because it's letting TOO much fuel into the rails.

TPS, IAC, CTS and the FPR have all been replaced. These all deal with fuel delivery.

Have i asked this on here before?
I probably have all sorts of codes, but have never had any luck pulling them, and a burnt out CEL doesn't help (but it doesn't annoy me being on hehe) So pulling codes is pretty tough. I tried with 2 volt meters and a light gauge. I had no luck, I got codes that were all over the place and not even applicable to my truck.

The guy over there (gasser forum), who I usually trust and is not helping much, said that any left over codes in the computer wont effect the way the truck runs.
Which makes no sense to me, because I think if the truck hits a code, that it will try and correct itself by adjusting fuel or something else.

Anyone have any idea's?
This fuel issue kills my gas mileage. It's very spiratic as well, sometimes it just will work fine. But i have really bad backfire issues while downshifting, and the high rev thing is eating up my clutch and causing problems while trying to slow down.
it's wierd to let off the gass and have the truck slow down in 2 or 3 different steps, you can litterally feel when the engine kicks down.
It's kinda like the choke is stuck on at all times, but remembers to turn itself off after 30 seconds, or sometimes not at all.

 

I think i just accidentally clicked on the yield sign. Ooops.

 

Have you checked to see if you have a vacuum leak? You can spray ether around where the vacuum lines are and if it revs that is where the leak is. That is what it kind of sounds like to me. I will think on this and get back if I come up with something.

 

I will report this post! Its in the wrong forum!! I do know how to fix your truck though.....BUY A PSD!! I will have to come back to help with your truck though. Heading out to do some errands. I would look into getting a scanner on it though to get the codes. That will be a big help. Though you may need to clear them then drive it then check them again.

 

Congrats on 3000 posts you got it on Tim's forum. So enjoy the new found HP.

Maybe that will fix the idle.
Oops it only gives you HP and not fixes. Sorry

Oops the HP only comes on trucks equipped with a PSD.
Sorry again.






LMAO

 

I need to clear them period.

It already rev's high, so I dont think it will change if I spray anything.
What should I spray?
I'm sure water wont change it. *shrugs*

Tell your dad to buy my motorcycle tim.
That way I CAN get a PSD.
I mean, he's all about the bettering of people, right? And helping others, right?
=) haha

 

Pull the EGR & clean out the tube (or the hole on the intake , which ever you have ) & sand blast the tip on the EGR ,,,,Pull a vacuum on it to see if the diaphram holds ...

 

thats cause you still buy that crap at the wrong pump.....or is this the thread where in the middle you say its solved and throw up a pic af a PSD?

 

EGR? Thats emissions return.

Isn't that in the back of the motor?
The exhaust return is gone on my truck, cut off by P/O, not that I owudln't do it myself.

or are you talking about the piece on the side by the TB?
I could pull that and clean it.
I checked for a vacuum on the line that goes to that before and there is no vacuum going to that, ever, even when the truck did idle properly.

 

hahaha, good one ron.

 

I had a 1985 F150 302 that did that. Delivering to much fuel, some black smoke and took me a couple months to find the problem. Anyway it turned out to be the MAP sensor not detecting enough vacuum. There was a crack in the vacuum line going to the manifold way .. way down in a bundle somewhere. I found it by putting a vacuum gauge on the MAP sensor hose and had little to no vacuum at idle.

 

Its on the front of the motor (usually )on the TB ,,,it is controlled( IIRC) ,by a temp controlled vac switch ,,At idle ,,the vacuum signal will be off ...

 

If the EGR is hanging open for a short time ,,the ECM will try to match the extra air volume with more fuel ...

 

Where is the MAP sensor at? I will check it.

Good idea with the EGR, that sounds like what the problem is!!!!
Damn gasser forum is useless compared to guys who are supposto be diesel nuts. laf!

 

When I said spray ether I meant to say spray ether. LOL

Anyway if you get some ether (starting fluid) and just squirt it around the hoses it will find the leak. What it is doing if there is a vacuum leak it will suck the ether in there and rev the motor.

I have had a few vehicles that have had problems coming back down to idle ie. revving and it was vacuum leaks.
Good call on the MAP also. Have you checked the timing? That will cause this issue also.