Hi everyone, this is going to be a long post so please bear with me.

I have a 93 F150 XLT 5.0L/E4OD 2wd.

I recently swapped the exhaust manifolds for BBK Shorty headers, removed/cleaned the upper air intake, rebuilt all the injectors, new cap, rotor, spark plug wires and replaced some of the old vacuum lines with new ones.

When I first got the truck back together it was running horribly and had a terrible exhaust leak. Turns out the EGR tube to the intake manifold had a crack in it so I fixed that and hoped for the best. The exhaust leak is gone but the truck doesn't want to run right when I am driving it.

It starts and idles fine but as soon as it is in gear and I start moving it bucks/sputters/bogs really bad almost as if I am down a cylinder. Prior to my "upgrades" the truck was running fine other than the exhaust gasket on the one side being blown.

When I was taking it apart there was a ground strap from the passenger side firewall to the passengers side of the engine block. I broke this strap when I was removing it and haven't replaced it yet, could this be causing my issues?

If I messed up one of the fuel injector o-rings during re-assembly would it cause a vacuum or fuel leak? There is NO raw fuel smell with the truck running and everything appears dry.

I have double checked my spark plug wire routing and it is correct so crossfire isn't the problem.

I am at my wits end and the wife isn't too pleased with the amount of time I have spent working on the truck this weekend, so any help/suggestions you guys can provide will be a HUGE help.

Thanks,

Grant

 

It certainly isn't helping them. Depending on the quality/integrity of the main ground at the engine block, that ground may be necessary.


It will result in a fuel leak if it is one of the upper o-rings. A lower o-ring will result in a vacuum leak.


I'd advise doing a smoke test for vacuum leaks first. Then we can proceed from there.

 

Yes you need that ground strap.
If that doesn't fix it, check your fuel pressure at the rail, and see if you have any fault codes in the computer.

 

ok so last night I unhooked the battery to clear any codes that may have been stored and re-connected the ground strap. The strap originally connected to one of the exhaust manifold bolts but it wouldn't reach so I attached it to the side of the upper intake manifold, will this work as a ground point?

I drove the truck to work today and it is running really bad, I am going to see if I can get it scanned for codes and go from there. I will let you guys know what codes are found.

 

Sounds like you have the plug wires routed incorrectly. Are you new to Fords perhaps? See the diagram below and double check against what you have done..

 

Well sometimes it is the simplest of things, I feel like an idiot now

The number 8 cylinder spark plug had a crack in it, new set of plugs and it runs like a top again.