Greetings everyone. I fixed my CYLINDER # 5 misfire ( see thread titled the same ) by changing out the spk plug and wire. I installed a new set this weekend after now getting codes of " MULTIPLE CYCLINDER MISFIRE, CYCLINDER 5 MISFIRE, AND CYCLINDER 6 MISFIRE ". When I pulled them my best friend who is a mechanic stated that the plugs looks like the engine is running lean. Just prior to this mishap I accelerated to get on the highway and the truck started cutting out like a rev limiter was kicking in. When got off of it no problem and I tried it again and no problem. When I got to my destination and parked the truck it sat for a few hrs. When I started it to go home t had a bad "MISS" then the CEL came on. When I pulled the codes the ones mentioned above came out. I went ahead and bought new wires, cap, and rotor ( not installed yet ) but my previous set of plugs were only a yr old and had only30K miles on them. Any suggestions?

 

Check your fuel pressure too.

 

Yeah that was 1 of the suggestions he said as well. I recently replaced the stock fuel pump with 1 from O'Reilly's last summer Airtex is the brand that most carry. He stated that I should have went back with a stock 1. Is there an area on this site that has those for sale?

 

Well, if that Airtex is O'Reilly's stock replacement, then I guess it should be ok if it can maintain the proper amount of pressure. Was the replacement pump shorter than the original? I think the only things listed on DF is used stuff.

 

Well that's the issue at hand. I don't remember if it was shorter or not but the entire assy looked exactly like the stock one. I guess I'm going to try the pick up coil, cap, rotor, and plug wires replacement to try and solve the "MISS" and then save some more money and try to re-replace the fuel pump.

 

It's a 98 and I see no mention of the lower intake gasket being replaced(plenum).(if the plugs look like it's running lean, odds are the plenum is ok, but shoould be checked) And has the cat been checked? And there is also a TSB on spark plug routing. And I would get a fuel pressure tester or have a shop check it.

 

It wouldnt be a bad idea to check the injectors as well. I made over 3 grand in guesswork repairs for what turned out to be rust that had accumulated in the injectors, dont want anyone to have the same experience.

 

yes we did the plenum work last summer due to oil being present when looking into the T.B. blades. The cat is what I really want to replace because it has never been changed and the truck has about 135K on it 90% highway driving and it was rattling a while back. I found out about the spk plug wiring rout the hard way and if you have a pic of it I could use it again when I install the new ones. I was told these trucks are notorious for rust in the fuel rail causing the injectors to become clogged. I have been trying to find a rail by itself but having a tough time. Would the fuel pressure tester be installed on the Schrader valve located on the driver side of the fuel rail? What should the pressure be?

 

I heard about the fuel rail causing rust to accumulate at the injectors. When we pulled the #5 injector last yr I noticed a screen on it. Would you suggest me pulling all of them and checking for rust on the screen or just replacing the fuel rail?