I have a 2000 blazer that is having major issues. We have tried replacing a large number of sensors and engine parts and still cant fix the problem. It cuts in and out at 3k rpm's and won't throw any codes. The only code its given was crankshaft position sensor fault that was replaced and the problem still exists and recently the crankshaft position sensor fault code came up again. We have tried literally everything possible short of replacing the ECM, the engine and the transmission. So we were thinking it could possibly be the rev limiter. Is that a valid thought? The transmission was replaced with a junkyard one about 4 years ago so thats why we are thinking the rev limiter. If so where in the transmission is the rev limiter located and where is the best place to buy a replacement for it. I checked rock auto and they dont have it. Thanks for any help

 

Come on guys any help would be appreciated

 

Where you ever able to fix it I'm having the same problem with my 95

 

I thought once you change the crankshaft position sensor you have to bring somewhere to do a CPS relearn or it will run like crap or not at all.

 

^^^ iian is correct for the most part. When the crankshaft position sensor disturbed, it will not send correct signals to fire the spark plug exactly when the cylinder is in optimum position. A relearn must be done with a capable scan tool. The ones you get from the auto parts stores cannot do it. You will need to find a shop or a buddy with the correct scan tool and the know-how to do Crank Variation Relearn. What code are you seeing? Is it P1345? If so, have you done anything with your distributor prior to the problem happening?

There is another adjustment that must be done when the bolt on the distributor is disturbed in any way. It is to adjust the Camshaft Retard. That would need to be doe prior to the Crank Variation Relearn. Do them at the same time.

If you answers are 'No' to the question above (though you will still need to do the Crank Variation Relearn), you need to start with a fuel leakdown test. Get a fuel test gauge (parts stores loan them out), and hook it up to the service valve on the fuel pipe heading into the plenum (it's a Schrader valve).

Turn your key to the 'On' position but do not start the engine (KOEO (Key On Engine Off)). In the first ~2 seconds while the fuel pump is priming the gauge must read between 60-66 psi. Far at least 10 minutes after that the reading should not drop below 55 psi. Post your results on this thread and there are folks here that can help you troubleshoot your problem before you keep throwing money at it.

 

So you cant go past 3k in park or even when in drive? does it misfire when you have it there? is it in limp mode? did you CLEAR all codes, even the hard codes? with a crank sensor issue if you dont clear the hardcores and perform a relearn i think it might be in a limp mode using cam sensor postion MAbey this is mainly an idea.
is you distruibtor drive gear worn?