2001 4.0

[amp1956]

This is actually my sons but I fix it for him about 8 months ago some how he ran it out of water and destroyed the 1st 4.0 I found a good used one out of a wrecked 2000 with very low mileage during installation we broke coil pack so I got a new borg warner( I think is a good one ) and then had to put new crank sensor on it 1st was cheap now have B W the thing ran great till the cheap sensor went out now we have a miss on number 1 its getting fuel I replaced Injector swapped plugs #1 was wet but seems like no fire on #1 what send spark to each cylinder ? its so bag has no power to run hardly have not tried to drive on the road :pray: Thanks for any help its driving me crazy . Alan

[4.3LXJ]

Since you have a new to you motor that was used, consider a few things. A bad injector can cause those symptoms too. Try some sea foam in the gas and run it for awhile. Also I have cured a miss on a 98 4.0 by running premium, again an injector issue

[amp1956]

I change the injector but thanks also I run Lucas in all my vehicles to prevent stuff like that and it works great I even run it in my 4 wheeler and lawn mower because the gas we get these days sucks

[4.3LXJ]

OK, just a thought

[slvmart]

Have you actually checked for spark at the #1 cyl ? If not, I would. Just to be sure you aren't chasing a gremlin.

[amp1956]

no way to check has coil rail goes over all plugs at once

[4.3LXJ]

Pull all the plugs and attach to the rail and turn the engine over and see if all plugs spark

[amp1956]

how am I going to ground it ???

[4.3LXJ]

You really only have to check one. But just make sure the metal of the plug touches metal on the engine and it will fire

[amp1956]

Can't hurt never thought about trying that way

[4.3LXJ]

You can narrow it down to spark or fuel injector that way

[slvmart]

You should also be able to put either a old spark plug cable hooked up to the coil pack, for the #1, and any old plug into the cable. Or if you have a inductive timing light, that should tell you if it's firing, or not. But thanks to everyone else for jumping in, while I was offline.

[amp1956]

Thanks for all the good info Ill try it but I still would like to know what sends signal to each plug ??????????

[4.3LXJ]

It is the PCM

[amp1956]

I know that but what triggers each separate cylinder ? is it the cps? I think I may have a short in my wiring harness but not sure where to start looking

[4.3LXJ]

Yes, on that one the CPS triggers each individual coil to fire