I have an 1995 S10 Blazer 4.3L with 103k. The engine was runing very rough. I had replaced the spark plugs (Autolite APP25) at 102K. So I removed the plugs and found that all of them were fouled (Pretty Black, but not oily). So I installed new Autolite APP25 plugs again, distributor cap and rotor, and spark plug wires, the old ones were all original from when I bought the truck at 50K. It runs much better, but I suspect that the ingintion is not the problem and that maybe the fuel filter and fuel pressure regulator may be at fault. So what do you think? I purchased an Dorman 55162 Fuel pressure regulatorand Fuel Filter from Parts America. Should I install them? Any helpful hints on replacing the Fuel Pressure Regulator? Also if the spark plugs were that black I would imagine the injectors probably look the same. So what would be the best way to clean them. Thank you in advance for any advice.

 

Best advice is replace those Autolite plugs which are only good in Fords,and getsome AC Delcos. Then run some 'Sea Foam' through the throttle body, in the gas, and in the oil 100 miles before the next oil change. This should take care of a lot. Fuel filter replacement was a good idea as well.

Good Luck

 

I just did the fuel pressure regulator and it improved the rich running condition on my Blazer but I still have a ignition related misfire to track down. The instructions on this site made doing the FPR pretty easy. I took off the small circular valve on top of the plenum first and looked in there with a flashlight, and sure enough, the passenger side was washed clean from the fuel leaking.

I'm not sure what else would cause the fouling of the plugs, though...

 

Thank you for replying. When your FPR was bad did you also have the same problem with the spark plugs fouling out? Thanks

*Combining Consecutive Posts*

Sorry lowbucktruck forgot to ask what brand of FPR did you use? I purchased a Dorman 55162 from Parts America. Any problems installing it?


*EDIT by swartlkk* - Combining Consecutive Posts - Please use the EDIT feature to add additional information to your post if another member has yet to reply. If you have any questions, comments, or concerns, please do not hesitate to PM me. Thanks!

 

I just bought the Blazer and never did check the plugs before getting right to work on the FPR. It smelled rich right from the begining.

I used the Dorman 55162 as well...no problems installing it, and it was the first time I had ever done one.