Sam hain

Finally got the miss fixed (in thread below), now I've got an ongoing issue with the knock sensor setting the CEL. I've kinda narrowed it down to coming on when the truck has been lugged for several miles. Reason I say that is because the last two times I've taken the truck the mtns for about 90mins or so the knock sensor will set a CEL. Granted I'm not talking mud holes and things like that, this is a national forest with gravel roads and the occasional rough spot where I have to crawl in 1st gear (in 2wd). The last two times I've been through the mtns that dang knock sensor has come on. The sensor itself is new (about 4months ago). I have a spare engine computer for my truck and I've had the knock sensor come on with both computers. I'm just not sure what to check for, the cause seems to stem from lugging the engine for long periods of time. Other than that the truck runs out fine and the CEL will stay off driving hwy speeds to work and back etc. I'm lost!

vasinvictor

iTrader: (3)

A guy in the 3.4 swap section had a knock sensor problems and ended up finding his cam timings off a couple teeth. Might pull your timing cover off the inspect the cam marks when the crank is on 0* tdc.

Sam hain

If that was the problem would the timing itself be off? Reason I ask is because I checked the timing when I replaced the distributor with a timing light and it was between 8 and 10* which I was told was good.

vasinvictor

iTrader: (3)

I wouldn't think that correlation can quite be made. The ECU has the ability to retard or advance the spark based on the information from the crank and cam sensors. Your ECU may be adjusting out to the max one way or another because your base timing marks are off.

vasinvictor

iTrader: (3)

Ah crap, I keep forgetting we're dealing with the 2.7! My knowledge is on the 5vz, so YMMV.

Sam hain

I thought maybe its a random miss the ECM isn't picking up so I did the seafoam treatment thru the brake booster last night. Also added some to the oil and the fuel. Going to change oil tonight and see if any crud comes out.