1993 Chevy Suburban Misfire issue

[gmcchamp99]

i have a 1993 Chevy Suburban K1500. When i got it, ran fine no but needed a tune up which i have already completed. When i did it i noticed the ignition pickup was cracked so i replaced the whole distributor. Since then i notice a skip / misfire. The timing is correctly set at 0 degrees TDC. I have since replaced the Distributor, Rotor Button, Distributor Cap, Wires, Plugs, Ignition module, IAC Valve, EGR Modulator and air filter. I have also cleaned the EGR valve thinking there would be a considerable amount of carbon buildup but it really wasn't that bad. I checked the intake gasket to ensure they weren't leaking as well as the Throttle Body Injection system gasket thinking perhaps that was leaking as well but both check out fine with a can of brake clean.... Only thing i could think is perhaps the distributor is defective or the ignition coil is? It mainly skips at low idle to about 1500 rpm and doesn't do it consistently, its more or so intermittent. I really notice is while stopped at a stop sign or red light or slightly can feel it when going up a hill at around the same RPM range.

Any ideas?

 

[zora]

how many miles on the engine and have you done a compression test?

 

[gmcchamp99]

284k. 51k on the rebuild. I have not done a compression test. i have noticed that when you stand in front of the truck when running w/ the air cleaner off, the driver side injector looks as if it sprays a lot less fuel than the passenger side injector. I'm thinking that the injector is possibly the culprit. Im open to ideas though. I will be changing the fuel filter tomorrow and the injector just to see for giggles if that's it.

 

[gmcchamp99]

I did a compression test today. Lowest cylinder was 3 @145ish. everything else was over 150. i ran a seafoam treatment through it and it helped the skip the slightest bit which leads me to think it's fuel related, more specifically the throttle body. possibly the one thing they didn't rebuild.

 

[zora]

compression sounds good and from your other comments looking into the TB injector would be the next thing