About a month ago, my 97 began having power issues. When accelerating, the truck would fall on it's face, set a 1211 code, then I could feel the truck revert to a pre-set icp signal. I would clear the code while driving and it would just happen again. This went on for a few weeks, then I put in my spare IPR valve. It did not make a difference. A day later, it SUDDENLY cleared up 100%. Now it started doing it again. When I think back, I remember this happening years ago on my 96, and I never figured it out.

 

Has this happened to anyone else? Anyone care to speculate?

 

Possable injector issue, possable ICP sensor issue... Need to get a scanner and watch it while driving.

 

Assuming a problem with an injector and assuming o-rings are good because oil level has remained constant after @ 1000 miles, What should I look for in the absence of a scan tool? Would it/could it be a broken intensifier spring? Does this happen? If this was the case, would the exhausted oil be flowing from the injector rather than pulsing?

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By the way, I have not looked yet to see if this is happening.

 

Cleaned the IPR valve and fixed it.

I had some piston damage that I decided to live with from a screw getting sucked in. (had to replace a head). Since each piece of debris (aluminum) either goes to the engine filter and is removed OR goes directly to the HPOP, my HPOP system was acting as a filter for the larger pieces. The HPOP oil reservoir was extremely contaminated!

 

HPOP oil was contaminated? What do you mean by that?