I'm really starting to wonder if the truck is running properly or not...

It get's good fuel mileage (avg 19mpg) and the power seems decent (for a rating of 185/360). The EGT's and the cold starts are what bother me.

All the fuel stuff is less then 5 months old EXCEPT the IP. Which I think is original (I base this on it's grey in color and the injectors I pulled said "2-91" on them).

On a cold start, even on a full 10 second glow (this system is ALL new and working perfect). The truck will puff white smoke on start up (not sweet at all, 100% fuel) and it'll misfire for just a few seconds, then be purring on all 8. I also noticed on a colder engine the truck idles smoother. If I've been running it all day (or a decent amount of time), when I come to a light you can feel it running a bit rougher.


EGT's are a different story. I can EASILY reach 1100 (probe in the manifold) if I stomp on it from a dead stop. Cruising at 2k, seems to bring around 600 or so. The only intake/exhaust mod's I've done is the Soup Bowl mod. Everything else is factory. I do notice the exhaust is TINY (compared to a factory PSD truck).

Basically, I'm asking what's your EGT? Turbo or N/A? Does mine seem high? Is the IP the issue? Timing? Lemme here what the IDI crowd thinks!

-Mike

 

How are the marks lined up on your IP? Sounds like it might be a bit retarded perhaps. Though it might also be a sign of it's age.

I'm running a 6.9L with the 093 ATS and 3"DP with 4" exhaust. My EGT is right at the back cylinder drivers side. C6 auto with 3.55 gears and 34.5" tires. Approximately 1/16"(if even that much, might be a bit shy of it) between the IP timing mark and the timing cover mark was the difference of ~ 850* full throttle empty and 1200* full throttle empty.

Injectors and the pump sort of wear together in a way. As the injectors age their pop pressure drops. Lower pop pressure means earlier firing (advanced). The injection pumps tend to take longer to build pressure as they age. This would cause the injection event to retard. The two aged together and it'll usually go un-noticed. However throw new injectors on an old pump and it'll have the net effect of retarding your injection event. You may be able to remedy it by adjusting the timing on your pump, but considering it's age, you might be best off replacing it. Look on the bright side... they're cheap compared to most others!


*edit/add
I've got a new set of glow plugs on mine as well as new relay etc. I've still got the old 6.9 controller yet. Over the winter she started up at just shy of -10*F with no block heater (didn't like it much) and it took about 3 glow/crank cycles. It started even better when I replaced the starter with a new one due to the faster cranking speed.

 

Mine was similar and I changed air filter and it did wonders. Warm idle is much smoother now and it was a 15$ fix. May not be ur problem but worth a shot. My egt probe is in manifold and I never floor my truck with my ip turned up. Egts will climb fairly fast. I have to try and get it up past 1000 though. Idles at about 275 normal driving is 400-700. Bogged or getting into it I hit 800-900.
non turbo e4od 4.10s and 37s

 

Thats why Im adding a intercooled. I need my pump to run hot and not have worry about egts.

 

Idle is 350 and driving is around 550-600 at 55mph on pretty flat ground. Though as soon as any decent amount of throttle is given the EGTs start climbing quick.

 

I'm surprised my 6.9 ain't dead from high EGT's. I guess what saved it untill I learned about EGT's is it's always been a high revving engine.



What would be syntoms of a high EGT abused engine though?

 

I think it is the IP, like I said I'm almost sure it's original and betting the timing is retarded too. I'm not sure where the mark's are, I've never looked.

 

Manic, my EGT is the same as yours. My I also have removed the soup bowl