Low rough idle 5.0L 1994 F150
01-08-2019, 08:59 AM
#11
The decal does not spec out idle; only 10DBTDC with spark plug, oil, etc. I set the timing about a year ago, so I will try that first before I dig any deeper. RPM's have always been consistent right around that 700rpm mark give or take when at idle at stop.
How did you figure out the cracked exhaust manifold? Visual? or???
How did you figure out the cracked exhaust manifold? Visual? or???
01-08-2019, 09:25 AM
#12
The decal does not spec out idle; only 10DBTDC with spark plug, oil, etc. I set the timing about a year ago, so I will try that first before I dig any deeper. RPM's have always been consistent right around that 700rpm mark give or take when at idle at stop.
How did you figure out the cracked exhaust manifold? Visual? or???
How did you figure out the cracked exhaust manifold? Visual? or???
So, I either pay a large amount of money and do a set of Torque Monster headers, or I replace the passengers side manifold again, this time taking time to make sure that the surfaces are flat relative to each other and that the middle where they commonly break is reinforced. I'll likely do that and use the TM headers for my engine in the stand.
01-08-2019, 12:22 PM
#13
Senior Member
Well, after chasing everything down, replacing some items on my "to do" list like ignition coil packs and a good tune up, that stumble was still present. I could hear a faint ticking noise from the passengers side that seemed to get a bit louder this last year. Using a automotive stethoscope, I figured out that it wasnt valve train like I originally thought. Confirmation was pulling off the manifold and having it fall into two pieces.... by the burn marks on it it was leaking for a while. I had a spare manifold off of a spare engine, and I replaced it with that for now. After replacing it, the stumble was gone, and my short and long term fuel trims evened out with the bank 2 readings. In the last 2 weeks the ticking has started again, and the stumble is back. So, I either pay a large amount of money and do a set of Torque Monster headers, or I replace the passengers side manifold again, this time taking time to make sure that the surfaces are flat relative to each other and that the middle where they commonly break is reinforced. I'll likely do that and use the TM headers for my engine in the stand.
So, I either pay a large amount of money and do a set of Torque Monster headers, or I replace the passengers side manifold again, this time taking time to make sure that the surfaces are flat relative to each other and that the middle where they commonly break is reinforced. I'll likely do that and use the TM headers for my engine in the stand.
01-08-2019, 12:28 PM
#14
01-08-2019, 04:04 PM
#15
I think I will check my exhaust as well. I noticed a tick of sorts at some time depending on warm or cool engine. Someone asked me one time if I had a bad valve. So, I will try to see if I can find anything as well......probably some visual at this time. I do have an old exhaust pipe cat-back and maybe at some time that has to be replaced; maybe do it all of there is something that I can find now....