Engine/Transmission (1994 - 1998) Lope And Know Harder Start

[MarsHill]

Hey fellas, heres my problem. My truck has suffered from a slight lope sense I have owned it. I have sense installed 5" exhaust, bhaf, gauges, ats 3 piece manifold, 3kgsk, afc springs, 16cm non-wastegated e. h. , and today 370 injectors. I thought it had a weak injector but guess I was wrong. This is what its doing. Slight haze at idle cold, lope still there and more noticable at lower rpms, when you romp on it cold or hot its alittle rough with black and white smoke? , cruising it runs strong with egt around 500 and wot only about 700 but 40+ pounds of boost? sorry for long post but please help.

 

[Vaughn MacKenzie]

Sounds like the timing isn't advanced enough. I would have it set to 15. 75 - 16. 0 degrees and it should run a lot better.



Another possiblility is you're drawing air into the sytem. If you have more than 200k I would definitely pull the prefilter all apart and replace the gaskets and I recommend a new heater element since these often short out (which causes an air leak around the electrial connector). Read more about it here--> http://www.nwbombers.com/forum/index.php?showtopic=15869

 

[Cooker]

I agree with Vaughn.



Also does it lope when the engine is cold only or both cold and warm?



With the engine cold and you rev it up some does the engine smooth out or does the lope get worse?

 

[MarsHill]

It lopes all the time, hot or cold and it seems to smooth out when you rev it up. If you rev slowly you really fill it between 1000 and 1600 rpms. If you romp it, its a little rough with gray smoke but if you go slow shes very smooth after about 1600 rpms.

 

[Vaughn MacKenzie]

Yep try the timing first, fuel system stuff second, then if you have a miss still try another set of injectors (although it's not likely they're the problem if it missed before the 370s).



Vaughn

 

[MarsHill]

Thanks for the help, I'll keep you posted

 

[Vaughn MacKenzie]

Good luck MarsHill, just hope your problem won't take you as far as mine (I doubt it will). My story in a nutshell: Timing, injectors, fuel system, injectors, total new fuel line, injection pump calibration, injection pump replacement, finally pulled the head to find a leaky valve

 

[MarsHill]

Do you think you could have found it earlier with a compression test ? If so, I will do that first.