White Smoke @ WOT

[Hunter4x4]

Quick question: At WOT (like standing all the way on the throttle WOT!) I get a pretty good cloud white smoke. If I'm on the e-way running 75 MPH and stand on it to pass, or I pull into traffic at 5 MPH and stand on it, I get the white smoke.



I searched the forums and noted that it might have something to do with pulling air into the system someplace but I'm not sure where to start.



Here's some truck history: I'm currently at 163k. The powerplant is stock except for Power Wagon injectors, a Baldwin BHAF, and straight pipe exhaust (4"). Absolutely no tweaks to the pump, turbo, or anything else.



I installed the injectors in June, and I love them - a noticable increase in performance since that date.



I'm experiencing no out of range gage readings anywhere (and I have a full set of gages).



And the problem might be intermittent - I can't tell if it is intermittent or if I can't always pick up the smoke in my mirror because the light isn't exactly right.



Mileage is around 17MPG for highway/rural driving.



Finally, I just changed my fuel filter last week - and what I honestly do not know is if I noticed the smoke before I made the fuel filter change.



And I mention again, the only time it smokes is when I am totally on the throttle - right up to the point just before I mat it - no smoke!



For the record I occaisionally got the white smoke puff at startup - but I think my search of the forums answered that question for me.



Thanks in advance for any input!!!



Mike

 

[Greenleaf]

Retarded timing and/or air



My P-pumped engines do this like all the time. Even in hot weather w/hot engine. It's due to retarded timing in my case.



Also I will notice this if I start a p-pumped engine in cold weather and try to give it some fuel. Won't work. Only white smoke and rough idle.



And as Columbo would say, "Just,one more thing"

It's possible to have the pump pull more fuel than the supply system can generate. This is associated w/ the white smoke and cutting out. Does your engine cut out/run rough whenyou see the smoke?



I have not seen white smoke from my VE pumped truck. Cold or hot/slow or fast speeds.



GL

 

[guava]

Mine has white smoke at start up and and I'm pretty sure its behind the timing curve do to age. I've also got air getting into the system from somewhere.



If I let it sit for a few days, it won't start right off because the pump has lost enough of its prime. Turning it over several times will do the trick. I've seen an occasional leak from the area directly under the throttle position sensor (if you have an auto).

 

[Hunter4x4]

Thanks for the comebacks! Greanleaf, there's no stumble or missing after it's warmed up. Runs real strong, just lays a nice 'mosquito fog' when I'm all the way on it!!!

 

[Hunter4x4]

OK, Here's my 'oOne more thing'!



Dumb question, but my inter-cooled '91 runs a VE pump, doesn't it?



Second question, then: Is there chance my lift pump might be weak at WOT? How do I check that? Or is white smoke at WOT OK?

 

["Mad Max"]

nawww, it's all good amigo - yer just a'seein' lots n lots of tire smoke!! :-laf

 

[Greenleaf]

Yep VE



You can install a pressure sensor fitting and connect a gauge to it. Keep it on there and use it as a test port. Installed where the bleeder screw is located .



-S

 

[BushWakr - RIP]

The smoke is nearly always timing related. . not ALL the time but quite often. .

The injectors need a bit of advance to help cope with the higher pop-off pressure (which has the effect of timing retarding due to the longer pressurizing time needed), so advance the timing and go from there.....

Yes the pump is a VE.

Don't be surprised if you fuel pressure at idle runs around 5-8 psi and at WOT it drops to near or on zero psi. If the pump is stock it may not go right down to "0" but it will likely get close.

Normally we want about 8-10 psi at idle and it would be ideal if we could have that at WOT too but unfortunately the stock lift pump won't keep up that well.



Hope that helps...



pastor bob...

 

[Hunter4x4]

Helps a ton - thanks PB!!