I have a 97 ford expedition we put a 99 5.4 engine in it. There are 2 sensors on the 97. 1 being the coolant temp. The other is one I'm not sure of but its under the intake manifold and behind the altinator. These 2 sensors are not plugged in because the new engine does not have these plugs on the wiring harness. The 99 engine runs fine at an idle but misfires and runs rough when rpm's are raised and underload. ? Should I put the wiring harness from the 97 onto the new engine and the coolant temp sensor in that engine as well? Sensor behind the altinator on the front bottom part of the intake manifold...what is that sensor? There is no place for it on the 99 engine? Please help.

 

ECT = EngineCoolantTemp Sensor. This is the sensor that was plumbed into the intake on the 97. Here's what you do, -

Use the 97 harness. With a brass "T" tap the coolant line "hose". Thread the sensor into the brass T, - Plug it in. It's a pipe thread, easy to find at the hardware.
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CHT = CylinderHeadTemp Sensor. Drivers side right front of head.

Both 97 & 99 have this sensor. That shouldn't be an issue with either harness.

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Unless someone knows a better way ?

 

once you figure out how many threads you need, I'll know where to post up to help out....

 

Your other two threads have been removed as crossposting is not allowed. One thread per subject so there is no confusion and members are not posting answers multiple times. Thanks

 

The brass "t" to put the coolant sensor in was already an idea but the wiring harness has no where to plug it in unless I am missing something. And I don't think I inderstand the other sensor. Its behind the altenator towards the bottom in the valley and the other motor didn't have it and there is no place to "t" it in if it can even be "t" in. I can put the coolant sensor in if I knew where to put it in at cause there's no place for it on the 99 harness.

 

Ok use the 97 harness. That will take care of the coolent sensor. The other one still. Stupps me. The one in the valley behind the altinator

 

IMTV (IntakeManifoldTunningValve) Right behind the Alternator.

Knock Sensor is below that.

 

Can I just do away with it? I mean can I. Just ignore it and not worry about it and just deal with a check engine light or is it required for my suv to run properly?

 

My guess is you are talking about the knock sensor, I swapped an '02 in and the knock sensor plug was different for some reason so I used my '97 knock sensor on the '02 engine with my '97 harness. I also took the temp sensor and just screwed it into the front crossover on the intake, there was already a hole with a plug in it and the sensor simply screwed right in. One problem I am having is with the two grey plugs on each head, I have one on the front P. side that is going to need a few inches added to the single wire to make it to the plug, the other is at the back of the D. side head but my harness has a plug for it at the front IIRC.

 

Converted. The 99 engine. It is. All. 97 now. Every ything is right . At a idle. It runs good all 8. Run it up hard and fast it miss fires and misses bad. Run the rpms up slow it hits on all 8 nice. Put it in gear and run it up it misses bad. But in gear run rpms up really slow it hits all 8 and lights them 33s up? What is worng now

 

Do you have a CEL and/or did it blink 4 or 5 times and shut off, while missing? If it idles fine, I would say coils or plugs.

Under normal acceleration and right after the shift into OD (about 45-50 mph), will it start missing ?

 

Ya any kind of heavy load. It misses and bucks. Its got new egr. Throttle positioning sensor. And new fuel filter

 

When I swapped the 5.4 into my 98- My coil packs and wires were running the 4six fine... but as soon as i swapped for whatever reason it would cause the 5four to miss under load. Swap them out and problem solved. Also when you swapped did you clean the throttle body and above prior to installing?

 

Ya. I cleaned. All that. So I got to. Put all of just one or the other. 97 or 99 coil packs. In it not miss mach them?

 

Your talking about coil on plugs (cop) not coil packs. As far as you mixing up cop's from your old motor to new, It won't matter as they are the same. But why not use the ones you know were good? Did your old motor have any misfire issues? If not, use your old ones and keep the others for spares. Sounds like you have a fuel delivery issue, but could be a misfire. Keep pushing it to misfire and hope that a CEL comes on to indicate what that issue is. Just one cylinder misfire can make it run like a dog