gmfan76

Hello all,

Need some help from those in the know or who may have dealt with a similar issue. I blew out the lower intake gasket on my truck. Replaced the gasket and intake (don't mix coolants!). Replaced the spider with a less used one. Now my truck has a miss on cylinders 4 and 7 i believe. Actually had the miss before replacing the spider. Also did cap, rotor, plugs, and wires. Any suggestions to causes or solutions would be greatly appreciated

OtherCarASaab

Have you done injector cleaner? Also, have you tried moving the injectors to confirm that it's related to the cylinder location, and not the injector?
If you haven't done those 2 steps, that's what I would check next. Moving an injector and seeing the problem move with it is a nice piece of hard evidence

I don't yet have a success story with my 5.3 misfire (cyls 8 and 1), but those are the next items I'd pursue in your troubleshooting (Beyond injector cleaner, plugs, wires, coil pack, and intake manifold, I've also done compression and leakdown tests, repl knock sensors and cam sensor, still missing, so I know your pain)
Best of luck!

shamrock246

How did the distributor gear look?was the cam retard set?whats the fuel pressure?might be time for a spider upgrade amazon has them for about $280

gmfan76

Thank you both for the responses. I'm actually going to dig into the truck this evening. What I can tell you: dist. gear looked great ( I've replaced that before), the same two cylinders we're missing before the spider swap.

I will update later when I've done your other sugg. and haveore info

gmfan76

Small update: we got the missing somewhat smoothed out. Dist. was loose and out of time. My exhaust is in terrible shape. I've got a factory system w/ 33,xxx on it and the O2's, going to hang it early this week. Will update soon

gmfan76

Update: hung the exhaust, replaced distributor, timed it (cam retard -1)tried a new mass air flow sensor(no change), new temp sensor. It's still giving me a p0300. The specific cylinder misfire was a mistake. It wasn't running like this before the intake gasket went. I don't get it

gmfan76

Put in a new egr valve as well, still stumbling. I had taken the old one off and gave it a quick cleaning. When I put it back on, it seemed to help. Very frustrated here. Currently have the neg cable off to reset the ltft. Does anyone know if the new dist. would've come with a new cam sensor?

shamrock246

Was that replacement spider the new or the old style?my#5 popppet stuck closed when i did my lower intake gaskets and i didnt even touch the spider,did you do a compression check ?