oh ok so it enters through the intake runners then. well im gonna put in a remanufactured spider assembly with regulator in the lower intake and i want to replace the lower intake gaskets too since im there because i smell antifreeze when its hot. but i was figuring to expoxy the holes that are in the lower intake manifold omly so that the gas would never go into the lifter valley should the fuel regulator fail in the future... but if its not a good idea and may affect the way the engine runs, then i wont do that. i just was thinking of a safety measure. this is the second motor in the truck because the first one spun a rod bearing because the motor oil got thined out because the regulator went bad and leaked to much fuel into the oil thinning out the oil way to much. what else should i replace while im doing this repair? is a reman spider from rock auto a good idea? thanks

 

im running Bosch platium +2 plugs and Jegs brand cap and rotor. the cap is a brass terminal type unlike the Aluminun Delco type. and my wires are jegs brand 8.5mm super conductor wires... should i remove the plugs?

 

i think you should try another leak down test again to confirm that lapping the valve there is good now for sure 100%. then you should start the truck at night and look for arcing between the wire and anything else. and also take a clean spary bottle with clean water and mist the wire there all over to see if it arcs. if it does then you know thats your misfire

 

The bosch +2 plugs are known to cause misfires on these engines. I would drop in a set of delco plugs. The same can be said for non delco caps for some years of these engines.

 

ok just got some ac delco plugs that the emission sticker calls for under the hood. should i change the cap back to the aluminun ac delco too? i have a 95 s 10 vortec "W" vin crab type dist...

 

Update:

Trying to summarize the situation I have. This thread has gotten confusing.

Have a misfire at idle, predominantly cylinder #5, although others will misfire as well. Even the even bank cylinders.

Have replaced Cap, Rotor, Plugs (now AC Delco - no difference), Wires, Coil, PCV valve. Moved parts around and #5 stays the worse. Just replaced the spider to teh MFI. Really didn't impact the misfire on #5 at all. Pulled the Bank 1 cylinder head and lapped valves. Brought compression up to 150 to 160 psi range.

Looking for next steps. Since predominantly on #5, I am thinking electrical. I don't understand how the ICM works and whether that could cause this sort of problem, or something specific to the distributor. At this point, the problem is not very heat sensitive. A bit better when cold, but I think that is just due to the higher idle speed.

New development. I went out to try and see if I was getting and kind of cross-fire of erratic spark and all of the wires and plugs were clean. Nothing around the ICM and coil area. When I sprayed the distributor with water however, I notcied quite a bit of sparking that looked as though it was actually coming through the distributor it self. I woud see the sparking at various places around the cap all at the me time. This is a new cap and rotor, but maybe I am onto something here. Have never done this before so I don't know if some level of sparking is normal or not. I suspect not, but looking for some advice.

 

arcing in the cap is no good and will cause misfires,aftermarket caps are junk i went through 3 (from advance) in one week before i got a good one lol

 

Hey, I thought I would chime in here. I just went through a terrible ordeal with a 2000 blazer "w" code engine. It had a miss on #2 primarily but some misses on other cylinders at a lower volume according to the counter on the tech II. This miss only occured after it ran for 10-15 minutes and then only under load. I looked at compression (good), replaced all the ignition components including a coil that looked like it got hot, checked the distributor which looked good but I shimmed it up so it only had .035" clearance. Vacuum looked good and steady and you could not see the misfire when using a spark light. I switched the injectors around on the spider even though the injector balance test showed within tolerance, still no resolution. No leaks through the intake or EGR either.
I ran across an aritcle where a very experienced tech found the solution with a crank position sensor. I was hesitant because there was no code so I convinced the chevy dealer to loan me a crank sensor since they couldn't find the problem either. Long story short...the crank position sensor caused the problem. She runs great now.

 

Thanks for the hint. A bit of an update since my last post. I ended up putting a new cap and rotor on from Napa as well as swapping out plugs again (Delco) and it is running much better. I am getting an occassional miss on cylinders 1 and 6 now. Still mostly at idle, but I do see it under load as well. Going to monitor it for a while and see how it goes. Not setting a light in the last 2 days. I may try your idea of crankshaft sensor to see if tat may clear it up. I also have no codes for that, but you never know. I also gave the MAF sensor a second cleaning. Cylinder 5 which was my big culprit is now running quite clean. Still have a feeling that 1 and 6 being intermittent are something electrical.