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1992 Ford Explorer XLT Runs Incredibly Rough After Flexplate Changeout

I have a 1992 for Explorer XLT 4.0 Fuel injected. About 6 months ago, I drove home after some erands, parked it, and came out the next morning to find out the flex-plate was shot. It sat for 6 months before being replaced and was running great–very smooth prior to this. New flex-plate installed and now when it’s started, it runs really rough, loping on some occassions, and not even idling on others. When I drive it and step into the accelerator, there’s a delay–like it’s either not getting fuel or air. . I’ve changed the plugs and fuel filter. I had just filled the tank when I parked it and been told the gas seperated while sitting. I’m at 5000 feet altitude and was wondering if that’s feasible and if not, what’s the next step? It is possible there’s a bad fuel/oxygen mix? It’s just been sitting and was running great prior to this. Checked hoses for a vacuum leak.

I suspect that the shop got the engine out of time when they R&R’d the transmission and never took the time to reset it correctly.

i never took the timing chain off so how can it be out of time? Can rotating the pully cause it jumpe timinmg by spining the fly wheel to align the studs of the tranny.

Did by spinning my pully with the surpentine belt off did that mess up my timing?

I believe that your distributor is at the rear of the engine nearly touching the firewall and when removing the transmission it is advisable to remove the distributor and replace it and re-time the engine fo finish the job. If the distributor is not removed it can get knocked out of time when it is pressed against the firewall.

Thank Rod. My neighbor is actually doing the work (he’s buying the car from me.) Would it be feasible to just resent the timing without changing out the distributer? We’ve already made the deal and I like to to avoid his extra cost, keeping expenses as reasonable for him as possible.
Thank You

I believe this truck does not have a distributor but a cam position sensor instead. http://fortuneelevatorconsultants.com/95explorer/newflywheel.jpg If it was damaged during the repair it can cause the issue you are describing.

I tend to think this problem is coincidental rather than being related to the flex plate replacement if the transmission was dropped to do this instead of removing the engine.

Six months is plenty of time for gasoline to go stale and especially so if it’s Ethanol.

You might check the fuel pressure and also take a gasoline sample in a clear jar to make sure the gas hasn’t gone sour on you.
If there’s any doubt about the gasoline, pour a spoonful on the driveway and toss a match on it.
If it flashes up quickly it’s good; it’s it’s sluggish to get going that may be the problem.

And of course make sure there’s no other gasoline or combustibles around while doing this.

Please let me correct myself. the 94 Explorer does not have a distributor. Instead it uses a coil pack that is timed from crank and cam position sensors and the cam sensor is in a housing much like the distributor and like the distributor it replaced it is located at the rear of the engine and against the fire wall.

https://www.google.com/search?q=timing+1992+Ford+4.0+Explorer+cam+angle+firewall&client=firefox-a&hs=1E8

-----look under images for timing------------

A drawing and several photographs of the sensor are in the link. It is difficult to get to the device without removing the upper intake and timing it can be a big problem. Hopefully my “best guess” is not correct. Reach behind the engine to check that the piece is not broken or loose and post back.

If there are no apparent problems with the cam sensor take the truck to one of the chain parts stores and have them check for codes.

And I had missed your post @SteveC76. I really should have confirmed the engines ignition system prior to shooting from the hip. But I recall the distributor on those engines being a pain and jumped to the conclusion that it was the problem here.