Idle issues 1995 ford f 150 5.0 to 5.8 swap
#1
02-25-2018, 02:51 PM
Idle issues 1995 ford f 150 5.0 to 5.8 swap
I recently had my 351 rebuilt to complete stock specifications. The motor was originally out of a 1995 ford e250 van. I’ve replaced every single sensor, solenoid, etc etc. I did remove the smog pump and eliminate all emissions components. Plugged all necessary vac lines and so on. I’m also using 19 lb injectors all brand new.
The truck is together and running great except for 2 things.
1 my idle at an initial startup is lumpy. The truck almost sounds like it’s growling. It will try to level itself off then it goes back to lumpy. My Toms are at about 850 900. If I press the throttle to about 2000 rpm for about 30 seconds you will feel the motor stop shaking and level off then idles fine then it will go back to the lumpy growl.
2 when I’m driving there are no issues it drives great when I come to a stop at a light it will idle fine. Now if I’m in 3rd or 4th and need to pass or accelerate if I press the throttle to about 3/4 it seams to flatline but will still slowly accelerate if I let off a little it will suddenly find power.
I’m thinking a fuel issue might be at hand or I need to swap in a f250 computer that’s for a 5.8l.
I did a fuel pressure test and my numbers seam ok. After 2 key primes it gets to about 35 psi. I start the truck pressure stays between 28 to 30 psi I hit the gas it goes up to almost 40 psi. I unplug the vac line it jumps up to almost 40. Now when in idle and it’s lumpy the fuel needle barely moves. It feels like it’s not providing air or fuel when it needs it.
The only codes which I had to check with a jumper are for insufficient egr air flow. And a code that says fuel pump inoperative. But the truck runs. Also when I hook up a scanner it says vehicle not responding even though it will start the test.
So do I need the bigger injectors and a computer swap.
Any input or thoughts would be greatly appreciated
The truck is together and running great except for 2 things.
1 my idle at an initial startup is lumpy. The truck almost sounds like it’s growling. It will try to level itself off then it goes back to lumpy. My Toms are at about 850 900. If I press the throttle to about 2000 rpm for about 30 seconds you will feel the motor stop shaking and level off then idles fine then it will go back to the lumpy growl.
2 when I’m driving there are no issues it drives great when I come to a stop at a light it will idle fine. Now if I’m in 3rd or 4th and need to pass or accelerate if I press the throttle to about 3/4 it seams to flatline but will still slowly accelerate if I let off a little it will suddenly find power.
I’m thinking a fuel issue might be at hand or I need to swap in a f250 computer that’s for a 5.8l.
I did a fuel pressure test and my numbers seam ok. After 2 key primes it gets to about 35 psi. I start the truck pressure stays between 28 to 30 psi I hit the gas it goes up to almost 40 psi. I unplug the vac line it jumps up to almost 40. Now when in idle and it’s lumpy the fuel needle barely moves. It feels like it’s not providing air or fuel when it needs it.
The only codes which I had to check with a jumper are for insufficient egr air flow. And a code that says fuel pump inoperative. But the truck runs. Also when I hook up a scanner it says vehicle not responding even though it will start the test.
So do I need the bigger injectors and a computer swap.
Any input or thoughts would be greatly appreciated
Last edited by drtyjrzy; 02-25-2018 at 02:52 PM. Reason: Notifications
#2
03-21-2018, 03:50 PM
I will say that I have had my 94' F150 with the 5.8L since it was new and it always idled rough. I can remember taking it back under warranty several times to address it but nothing ever worked. Other than the idle though it always ran well. Of course if you have an air idle solenoid or the idle control going bad it can get really crazy but it doesn't sound like you are having that big a problem?