Engine Swap

[Puremuscle]

I found a 4.0 motor to swapp into my 93 ex. the issue is the engine came out of a manual shift and i think it has all the california stuff on it and the harness is different. have and auto with black injectors and this one has red injectors. i know i have to change flywheel flexplate but will the other differences affect anything.

thanks guys for any help.

 

[natenkiki2004]

From the tidbits I've read, you'll probably have to swap stuff on the engines before you pop the new motor in. The red injectors are the newer style but same specs.

The computers will be vastly different so I think everything electrical from your old engine will have to be moved to the new one.

 

[vq5speed]

Do you know the year of the motor is it a OHV 4.0.

If its a OHV motor you should be able to just strip it down to a long block and put all your stuff from your motor onto it. That includes the senders and sensors so everything hooks right up to your harness.

 

[Puremuscle]

i don't know the year, but it is a OHV 4.0 from a first gen explorer. I had to remove the upper intake because it had something hooked into the exhaust man. which was not on mind, in addition to a few other hook ups. I got it in but it won't start. If i spray starting fluid in the TB it runs. Fuel is getting to the rail but i think the injectors may not be functioning. i didn't switch harnesses because it appeared that the connectors and wiring were the same. Guess i'll put the harness from my engine on it and see what happens. Thanks.

 

[Turdle]

There are 2 types of fuel injection systems in 1st gen . You are on the right track by using the original harness.

 

[Puremuscle]

i kida figured it would be more than one in one out. It's just that the harness on my engine was cut, hacked and spliced (and had to be in the right position or all kinds of idle issues would occur) before i got it, and the other one looked so neat and clean thought i'd be able to plug and play. Now going back to the different color injectors, natenkiki2004 said the red are the newer style. so i assume there is no electrical difference between the two and shouldn't give me any trouble, right.

 

[Turdle]

The harness is the issue.

Batch fire injection has 2 common voltage switches to the injectors, while sequential injection has separate channels for each injector. The wire harness cannot cross over to the old PCM either way. If you care to click into the 1993 vitamin d link in my signature you can see how I fought this same thing. You need the correct harness for your PCM.

 

[natenkiki2004]

The injectors are definitely the same specs and connection and will work when swapping them in/out. I've talked to a major injector rebuilder and verified this. The difference between the two lies in the end, one has a pintle (older) and the other has a more sophisticated tip with 4 holes that injects fuel in a finer mist and should yield a better/more even burn.

But yea, the harness is what you need. Ford switched a bunch of little stuff mid-generation and that's one of them.

 

[Puremuscle]

yeah, i should have known. I am a ford person and i have worked on my fox body mustangs of the same year, but depending on the month it was built will determine which part number to use for the same part - drives me crazy. but thanks for the help. guess i'll try to go to the pick pull and get a better harness like the one i have and go from there. Knew i'd get the answers i needed here. Again thanks a lot. let you know how it goes.

 

[vq5speed]

I don't think its a harness issue. I swapped a 95 long block into my 91. I didn't change my harness I just put everything from my 91 onto the 95 motor. There are a lot of other things that would keep the motor from firing. What was the reason for swapping your old motor out?

 

[Puremuscle]

Son ran it so hot that it blew head gaskets and melted number one piston. it started out being a head gasket/head work repair, but turned out to be much worst when i took it down. the truck ran fine other than the butchered harness that had to be in the right place or the idle would go crazy or it would not start due to the Crank Position Sensor wire being cut so short and repair at the connector.
Turdle, i read the link and i think i may have the same issue except in reverse. The symptoms sound the same. My engine had one connector for the O2 sensor this one has two- my harness had one square and a smaller round black connector that hooks to the main harness the other one has two square one grey one black and all that other stuff on driver side upper intake and a thing one the back of the engine I think its the Cam PS. I remove upper intake replace with mine removed CPS and replaced it with the pump drive that was in mine. So, i think the harness my be the issue. i'll see. Sorry didn't know how to do all that quote stuff i see you all do.

 

[Turdle]

I don't think its a harness issue. I swapped a 95 long block into my 91. I didn't change my harness I just put everything from my 91 onto the 95 motor. There are a lot of other things that would keep the motor from firing. What was the reason for swapping your old motor out?

Yes but you used the 95 harness. His "original " harness had issues so he tried using a different one. The harness is the issue. I am certain without even seeing it.

 

[vq5speed]

No I used my harness I didn't switch any harness. The only thing I used from the 95 was the long block.

I'm just a little confused.. I thought he said originally he didn't switch harness's then he said he had to use his harness. If you didn't switch harness then you were using your harness.. what did you switch to
But if his original harness was missed up before he swapped motors then that's what I was trying to find out.

 

[Puremuscle]

Update: I want to thank everyone that gave me some input, but especailly to turdle and the vitamine d thread. a few minutes of reading your pain no dought saved me days of head scratching, part chasing and discouragement; but instead, 45 min with the air wrench - remove harness and replace with the one from the old engine turn the key spruttered - shut off, turn the key again and nothing but smiles on my face. hope the next person who does a swap finds this forum and read these threads.... Oh yeah gonig to pick-pull to find a decent harness. thanks again guys.

 

[Turdle]

Make sure you keep us updated with the newer harness. Pay close attention to the soldered junction for the common line to the fuel injectors. If you follow it into the harness you will find where it all ties together, I found several harnesses had tuned into copper verdigris there. Maybe it could be repaired?

 

[vq5speed]

That what I was saying I didn't switch harness's in my swap. If you had not cut out your original harness it would of started.

 

[Puremuscle]

I will pick one up this weekend, but will be sure to pull one exactly like mine with automatic trans, one O2 hookup, non cali emission and in good shape. I'll report back.
Side bar. where do i find the instruction to show how to put a quote from someone else in a reply.

 

[mr cribb]

Your build date must be mid 92 for your truck.

I'm on my 3rd first gen (91, 92, 93) The 91 had one O2 build date 4/91. The 92 build date 12/91 had one O2, now my 93 has two O2s no EGR build date 10/92.

I have a harness with one O2, but it is from a manual trans truck. I know nothing about the automatics, and I refuse to own one because I like to shift.

If you can use the harness let me know.

 

[Puremuscle]

went this weekend and pulled a harness from same year and modle with automatic tranny. Same 4.0 EFI logo. had no issues. removed the old beat-up one plugged the other up - ran like a champ. Harnes was definitely the problem i had in the beginning. FYI to everyone. Make sure you have the correct harness when doing a swap. Until the next issue...

 

[larrydd999]

Puremuscle, the answer to your quote question is - below the message window there's the 'quote message in reply?' box.