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Misfire

wagonproject

By wagonproject
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wagonproject Enthusiast

wagonproject

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My 1996 runs like shit. It sat for 10 years and am I am trying to get it running right. It runs like shit. I've replaced the gastank, fuel pump, fuel filter, spider injector, plugs, wires, cap, and rotor. And it still misfires. The check engine light stays on when you first fire the truck but as soon as you go it starts flashing. A buddy took it today and put his code reader on it and said it has a misfire code and that it said it could screw up the converter which I read on here also. It said #1 cylinder is misfiring, like it misfired 110 times since the last key cycle. He took a compression test on the #1 and it was like 55 or 60, tried the one next to it and it was the same. Tried one on the other side and it was 55 or 60 also. Hes not sure if hes tester is bad or what so hes going to have NAPA switch it out tomorrow. And he had to go so he couldn't do much more. When I got it back tonight I pulled the plug on the #1 cylinder and it is getting spark. Any ideas?

Jsdirt Senior Enthusiast

Jsdirt

Posted
Posted

I'm thinking you'd have more than just #1 misfiring if the compression is indeed that low. An engine wouldn't even run with comp that low.

 

Could be the gauge, or you could have a bunch of lifters that collapsed from sitting. Could try changing the oil & throwing in some 0W-20 or other real thin oil to try & see if that pumps them back up. OR you have some valves stuck.

wagonproject Enthusiast

wagonproject

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I'm thinking you'd have more than just #1 misfiring if the compression is indeed that low. An engine wouldn't even run with comp that low.

 

Could be the gauge, or you could have a bunch of lifters that collapsed from sitting. Could try changing the oil & throwing in some 0W-20 or other real thin oil to try & see if that pumps them back up. OR you have some valves stuck.

 

Thanks for the response. The gauge might not work, im not sure. Hes going to trade it out later today.

 

If a valve was stuck wouldn't it backfire?

Jsdirt Senior Enthusiast

Jsdirt

Posted
Posted

I would think it would .... but you never know.

wagonproject Enthusiast

wagonproject

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Fuel pressure is 40 when the truck is running. Is that to low?

 

The codes it comes up with are.

 

P0102 - MAF or VAF a circuit low input

P0301 - Cylinder 1 misfire detected

 

I am going to try to do a compression test tonight.

wagonproject Enthusiast

wagonproject

Posted
  • Author
Posted
Fuel pressure is 40 when the truck is running. Is that to low?

 

The codes it comes up with are.

 

P0102 - MAF or VAF a circuit low input

P0301 - Cylinder 1 misfire detected

 

I am going to try to do a compression test tonight.

 

I had one of my old timers from my shop come look at it tonight. Compression is about 110-115 on all cylinders including #1. The spark plug on #1 is dry so its not getting fuel. Though when you first start the truck it sounds like it runs on all 8, then a couple seconds later it sounds like it drops one. He said since it did that he doesn't think its a messed up injector (though it could be), or the camshaft. Its most likely something inside the comp. is messed up or a wire.

 

Does anyone know what year comp. will work in the 1996 with the 305? Also would a comp. for a 350 work or no? See if I can swap a comp. to see if that does anything.

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