Random issues

[black97xlt]

I have a 97 xlt with 5.4. I have changed the plugs and installed new Accell cop's. I still have a random miss and stutters occasionally. It sorta misses while in park at 1,500. then it pretty much misses here and there while driving but not often and not at any particular rpm. When under load or going up hill at wot it misses alot more. The reason for buying the new cop's was because the 45 degree elbow that broke and leaked all over the place. apparently had been leaking for a while because it had been dripping on the exhaust mani and caused a bunch of rust. I even broke an exhaust stud off trying to remove it. (now another issue I have to address. it broke off inside the head! Weld a nut?) anyways, trying to get this thing running better then it used to and I need any ideas as to why this thing is still missing and acting up. it only has 120,000 and has been maintaned all except for this issue. thanks in advance.

 

[Bowesmobile]

I would start checking for vacuum leaks around the intake. Look at all your hoses. In-particularly the ones at the back of the intake. I dont want to send you in the wrong direction on the exhaust stud. Also, what 45 degree elbow?

 

[black97xlt]

the one on the backside of the intake mani on the right side. I have looked all over for vacuum leaks. actually just replaced a few.

 

[Bowesmobile]

You could have a gasket issue. Use intake cleaner and spray it along the gasket area between the intake and head. If the engine RPM changes, then you've found it!

 

[Mediamonkey11]

You idle at 1500rpm??

 

[IMINYOURCHAIR]

You idle at 1500rpm??

He may mean in P with the throttle held to 1500 revs.. at least I hope. going from P to D at that rev would be...harsh.. to say the least

 

[BAD RONALD]

You could have a gasket issue. Use intake cleaner and spray it along the gasket area between the intake and head. If the engine RPM changes, then you've found it!

This is good advice, here is some more: DO NOT spray cleaner on a hot engine...this check is OK when things are warm only. It is WAY safer to use bottled propane to do the same check. Attach a hose to the end of a plumbers torch, turn on the gas but do not ignite. Introduce the propane to the area between the intake and the head and listen for RPM change.

If this doesn't work for you have a smoke test done.

 

[tonydiv]

You didn't mention if you had any codes popping up.

Also, I use the propane method for finding leaks. It allows you to get motor warmed up and test without any worries of fire.

 

[black97xlt]

I already fixed the leaking issue. just have to fix the damage it caused and no it dosn't idle at 1,500. that's in park and revved and that's the only rpm it will miss at when in park and only if you hold it there for a few seconds. so far as I can tell there are no more vacuum leaks. new intake mani gasket and new hoses. no codes.

 

[black97xlt]

tonydiv, that is a bad ass truck!

 

[black97xlt]

What else could I look for? I've gotta get this thing running like a champ.

 

[DF5.4]

When was the last time the fuel filter was changed?

 

[bedrck46]

sent you a PM

 

[black97xlt]

changed the fuel filter a month ago.