Greetings all,
I am a new guy here, been sort of lurking about for a month now but have not seen a problem quite like mine here so will ask the experts.

I have a '98 Blazer with the 4.3, 200K on the clock. Have owned it for just over a year now with no real driveline problems. About a month ago it started to develop a slight miss, only after startup before it went into closed loop operation. As soon as it went into closed loop it ran great. This progressed to a more noticeable miss and then into a miss after closed loop. About two weeks ago the miss got bad enough that it started backfireing, power loss became noticable. The only code shown was the P0300.

I did an ignition tuneup consisting of new cap, rotor, wires and plugs. This made no discernable difference at all. While doing the above I did notice that with the #1 cylinder @ tdc on the compression stroke the rotor was not quite aligned with #1 on the cap. This led me to think that perhaps the timing chain was the culprit. I checked and found that although it had not jumped it was badly stretched so I replaced it. On reasembly I installed a new (composite) timing cover.

Yesterday I got it all back together and it would not start at all. On checking I got a P0335 code. Upon closer investigation I see that the CKP lacks about 1/16 to 1/8" of being seated completely into the new cover. Retrying to seat it by pulling it out and relubing it and reinstalling it did not get it clear in. Further inspection shows nothing I can see that is preventing it from seating. Even tapping lightly on the edges will not make it go in further and I am reasonably certain that this is what is causing the last code.

This leads me to two questions. Am I on the right track to repair the original problem and has anyone else had a problem seating the sensor into a new cover???

Any light that could be shed on these would be highly appreciated, thank you in advance.

 

Oh, I forgot to mention that during cranking it will commonly "kick back" and bring the starter to a brief halt. If it was my old Harley I would be laying over the handlebars.

 

Did you wreck the old cover? If not use that one?

 

The old cover, despite great care, was cracked at removal. I had been told that it would most likely happen and it did.

 

Since you replaced the timing cover, you have to do a CASE relearn. I know the tech 2 can do it. Before you do that check the CMP retard, it should be 0 degrees, plus or minus 2.

 

take a look at this maybe it needs to be shimmed out https://www.youtube.com/watch?v=KLC0E7N47Lw

 

That of course is possible but won't be of any use to me until I can get the sensor seated in the housing as I am sure that it will not start until I do so. I am at this point disinclined to dismantle the whole thing again. If I cannot find a reason why the sensor won't seat I will most likely just junk the unit as it sits and get something that runs without giving me all the grief. I have put enough time and money in it already for something that is only half a usable vehicle anyway.

 

The problem is NOT that it is hitting the reluctor, it won't even come close to it!