I just replaced the intake gasket on my 2001 Blazer. When I pulled the distributor I didn't mark its position so it took me awhile to get it to start. It now starts fine.

It idles a little bit rough, doesn't have the same power as usual, and the CEL is blinking. The CEL was on before I replaced the intake gasket and it was showing MAF, O2, EVAP and fuel level sensor codes, but it never was blinking until now. It seems like a miss-fire, but the plugs are new, and I checked to make sure all the wires are correct. I don't notice any exhaust/fuel smells.

I'd like to try to get an idea of what the problem might be before I waste my time and money. Thanks for any help.

 

make sure rotor is pointed at the little 6 on dist... it could be off some if ur still setting off engine code...

 

A blinking CEL indicates a misfire as you have surmised.

I would go through the EDI engine timing thread in the Tech Article (DIY) Index link in my signature. As stated above, make sure the rotor tip is lined up with the '6' in the distributor base after you have properly aligned the two timing marks on the crank balancer.

 

I just went back and made sure it was timed correctly, timing marks lined up and distributor on 6. I replaced the plugs about a month ago, and the wires seem ok. Is there any way to check compression without taking it in to a shop? I don't know what else could cause a missfire besides bad plugs or wires.

Also, is it possible for a loose distributor cap to cause this problem? At some point I over tightened one of the bolts and the plastic threads cracked. I can still tighten the other bolt, but the cap can move slightly.

 

You just need to get a compression tester and remove the spark plugs.

As far as the distributor cap goes, if it were not properly seated, it would have the same effect as the distributor cap being mis-timed.

 

Well I am kind of beyond my mechanical skills when it comes to things like cylinder compression and diagnostics. Is it possible for something to clog a cylinder and cause a missfire? I'm thinking it has to have something to do with the intake gasket repair I did, it was running perfect before that (besides leaking coolant) but no missfire. Its pretty bad too, visible and audible knock at idle, seems to be worse at low rpms.

I just went over the whole engine and made sure everything that got taken apart is put back together and connected. I tried to cover all open ports with rags when I had the intake off, but the only thing I can think of is that some piece of dirt or grime got down where it shouldn't be. Kind of a scary thought. I would like to go and get the engine error codes checked but I'm not sure if I could even drive it to the auto parts store. I don't really know where to go from here.

 

You didn't happen to leave a rag in the intake port did you?

 

Oh jeez I hope not. I'm pretty positive I would of caught that but I've done worse before. After reading a few other threads I'm thinking it may be a fuel injector. The noise at idle seems to be coming from one side (hopefully just one consistent cylinder, not a P0300), the spider was pretty covered in carbon when I pulled it off. From what I gather, I can pull the coil and turn the engine over, the wet plugs are ok, the dry plugs are bad injectors. Am I getting that right?

 

Depends. An injector may not be opening in which case your description is correct. An injector could also be not spraying properly which will put fuel into the cylinder, but not have it atomized for proper combustion.

I would go through and pull the wires one at a time with the engine running listening for a change. If you do not notice a change in the engine at one or more cylinders, then you have found the problem cylinder(s).

One other thing to check. Pull the connector off of the top of the spider and check that all of the pins are still nice and straight and that none are bent over.

 

BINGO! Bent pin. Two days of worrying about this truck comes down to a 1 minute repair. Thank you!