Late 80s crown vic EFI harness in a 88 bronco

junkyardjeff · February 18, 2018, 04:23:33 PM

I got this 88 full size bronco I swapped over to 2 wheel drive and since the gas tank is in the rear it could get a true dual exhaust very easy,since the late 80s crown vics could get a true dual exhaust they have dual O2 sensors so I got this ideal of using the EFI harness from a crown vic and installing it in the bronco so the EFI will work right when it gets a dual exhaust. Does it sound like it could work,I could switch to a carb and it would be much easier but would like to keep the EFI.

enjenjo · February 18, 2018, 07:42:21 PM

It should work. Hollander says the engine interchanges.

junkyardjeff · February 18, 2018, 08:17:03 PM

They both have the all the same sensors except the cv has 2 O2s but are in different locations,I might grab both harnesses at the junkyard and lay them out on a table and go from there.

kb426 · February 18, 2018, 10:15:32 PM

Are they both mass air or speed density? The Bronco maybe hydraulic flat tappet and the vic might be roller cam. The reason I ask is one is sequential and the other is bank fire on the injectors. If both efi systems are the same, I'd check the pinout on the connectors just to be sure before swapping.

junkyardjeff · February 18, 2018, 10:40:06 PM

I think both are speed density and I do think the CV motor is roller and not sure with the bronco,the body is about shot on the CV and might drop the motor with the car EFI in the bronco when the frame goes.

kb426 · February 19, 2018, 08:31:22 AM

I believe all speed density versions will work with 1 o2 sensor. The 91 f150 engine I used in my clean out the garage project had 1. I have it in the right bank as the original was. It has duals but I can't say that I just went on e 1000 mile trip and checked gas mileage to be sure everything is as good as it should be. Because speed density is bank fire and both banks receive the same signals, I think 1 is all that was required. What I don't know is if the crown vics ecu is different and required the 2 sensors. I'm not much help.

junkyardjeff · February 19, 2018, 08:48:49 AM

If I do put duals on the bronco I do not want one side of the motor running rich or leaner then the other side.

kb426 · February 19, 2018, 08:55:23 AM

I understand. What I was trying to say is that the ecu sends the same signals to both banks based upon the o2 sensors input. If the crown vics ecu uses both signals, it should be more accurate. To the best of my knowledge, all the 5.0's in the pickups before mass air all have 1 o2 sensor. The f150 I used had had duals for most of it's life. The internals of the engine looked the same for both banks.

junkyardjeff · February 19, 2018, 05:20:40 PM

Maybe I am thinking too much.

wayne petty · February 19, 2018, 05:48:45 PM

there are 2 different 5.0 EFI motors..

the EFI 5.0 on the top of the intake plenum.. is a batch fired fuel injected motor. the left injectors then the right injectors fire.. this uses a conventional 302/5.0 firing order..

the HO 5.0 engine with the id plate on top of the plenum. these are sequential fired fuel injectors and have the 351W firing order that has the 4/7 swap if i recall.

the computers.. main harness, engine harness are different between the motors. i am not saying it can't be made to work.

another thing just lately.. i have been running into a bunch of bad PIP pickups. in the TFI distributors.. the pickup coil assembly.. its a hall effect unit.. the distributor gear is pressed on and has to be pressed off and back on with care to not damage the shaft or upper mounting plate.. or by a reman distributor. lately AZ has killer pricing on them.

will the harness swap from the pickup body from the car body? any thing is possible. i thought you should know there may be differences..

ps.. the real unrebuilt 5.0HO motors from 88 to 92 or 93 actually came with a roller cam, and real forged pistons.