ronnielwebb74

Hello people,
First off I have a 97 f150 4x4 with a 4.6 in it.
The runs rough while idling. But, when the engine reaches about 2500 rpm's it feels as tho it smooths out.
Anyway, I have access to a 99 Mercury Grand Marques with a 4.6L engine that runs good.
My engine is a Windsor and the cars is a Romeo.
Would it be worth it and can it be done to replace the truck engine with the car engine?

Marc D

The two motors are just built at different plants, Windsor and Romeo plants. There are possible differences however since Ford has a 2 valve and 3 valve at that time. The motor will bolt in fine but there will be wire harness modifications that will need to be made and some computer flashing (reprograming).
I would spend $100 and have complete detailed diagnostic report done first on your truck. You may only need some minor work, even if it has high miles.
BTW try some SeaFoam in your gas to help clear your fuel system.

ronnielwebb74

I have tried sea foam both ways.
In the gas tank and through the vacuum lines.
New coil packs, plug wires, plugs and a fuel injector on #8 cylinder where must error codes is coming from.
Cleaned all carbon out of the throttle body.
Tested gas pressure.
Tried compression check. But, can't get the threads to start in the head on #8 cyl. of the compression tester hose.
Many different fuel injector cleaners.
If I could just get a compression test on #8 it would help diagnose most of the problem.

Chromeshadow

I have a rubber plug adapter for my compression tester-it's a little harder to use- I have to hold it pretty tight, but I can get a pretty good reading with it.

Marc D

As crazy as it sounds I have pulled the front wheel and the wheel well off the truck to access the rear plugs. It's not difficult and takes about 45 minutes. You are correct in assuming you need the #8 cyl. comp. test data for the total diagnostic picture.