Random misfire

[Ranger-Justice]

Ok have 89 ranger with 2.9 everything was going good replaced spark plugs, wires, distributor and cap about a 3 months ago. Been driving it for 3 months been having a pretty bad exhaust leak so I decide to fix it. Put a ne flange gasket on it and it stopped the leak but now the truck misfires and will not idle. I can make the truck run my holding the gas but is running very bad. When I did the gasket I didn't touch the engine at all so not real sure whats going on. I replaced the spark plugs again just to be safe and still no the same. hooked a OBD1 reader up and it says cant connect to truck. Could it just have jumped timing for no reason??

 

[hoosier1104]

A misfire is caused by a couple things; bad plugs/wires/coil, cat clogged or a grounding issue. Check the firing order on your wires and continue on down the list.

 

[Ranger-Justice]

firing order is correct checked it twice and have been driving it this way for at least 3 months

 

[hoosier1104]

Move on down the list then.

 

[Ranger-Justice]

just put a new coil on it and the same problem. I have done everything on your list but grounding. what would I be looking for exactly?

 

[Andy D]

You want to see a heavy duty strap or cable between the engine and the frame and from the engine to the firewall. I would look at the left motor mount area. A wonky charging system might do it too. On an old truck, wires get very delicate., You might have nudged it and that was enough. It was enough to part the cable at the starter when I first took it off.

 

[Ranger-Justice]

oh the actual ground cable I thought he meant look for the spark plug wires grounding some how. I will check that in the morning!

 

[Ranger-Justice]

I checked the grounding cable no issue with it. Any other ideas. I'm at a loss. new plugs, wires, cap & rotor, coil, grounding good.......

 

[hoosier1104]

Drop the cat, shine a flash light or light source through it. Cannot see the light, you found the problem.

 

[hoosier1104]

Could also be a fuel delivery issue as well.