What swap to do?

[lil_Blue_Ford]

Should be a pretty straightforward swap, but you will have to swap engine wiring harnesses. Not all that hard, I could just about do it blindfolded at this point. Label and save the harness you take off though, someone may need it. I don’t think the 87 had EGR, that would be the only real issue I can think of.

I would also take the opportunity to do new head gaskets and a new water pump plus whatever I might want to do to the motor before dropping it in. overheating kills these motors so it’s cheap insurance to give it a little overhaul in my opinion.

 

[EasternNC]

Should be a pretty straightforward swap, but you will have to swap engine wiring harnesses. Not all that hard, I could just about do it blindfolded at this point. Label and save the harness you take off though, someone may need it. I don’t think the 87 had EGR, that would be the only real issue I can think of.

I would also take the opportunity to do new head gaskets and a new water pump plus whatever I might want to do to the motor before dropping it in. overheating kills these motors so it’s cheap insurance to give it a little overhaul in my opinion.

Thanks! My plan is a complete tear down, hot dip, and rebuild. Plus all new everything on it. Also I want to do any upgrades there are. Know of any good rebuild kit sources?

 

[rusty ol ranger]

The 89 will be plug and play.

The 86/87 2.9s had a knock sensor and an EGR valve, the 89-92s do not. Your 87 ECM will toss a code looking for these things but itll run it just fine. Or use the 89 ECM assuming both are the same type of trans.

As a bonus the 89 has the slightly less crackable heads.

 

[EasternNC]

The 89 has an automatic and the 87 has a manual. So, with that being the case, should I import the 89 harness and computer to the 87 truck?

 

[Rick W]

I got my ‘87 free from a buddy with a rod through the 2.9 block. I had to hunt around a lot to find a good used motor. Most of the motors I found were around $500 and high mileage. I lucked out and found a truck that had been wrecked, where the engine has been rebuilt with the updated heads 40,000 miles before the wreck. It cost me $900 delivered and it cost me $500 with a shade tree to put it in. That engine came with all the bolt on stuff, so now I have spares for everything.

One of the reasons I had a hard time finding one is because over the years as the trucks went to the scrap yard and folks with trucks on the road wanted to replace the engine, all the 2.9‘s got gobbled up, everyone wanted the biggest bolt-in engine.

I would also take the opportunity to do new head gaskets and a new water pump plus whatever I might want to do to the motor before dropping it in. overheating kills these motors so it’s cheap insurance to give it a little overhaul in my opinion.

& I agree with @lil_Blue_Ford on updating the cooling, but one step further. I’m not sure the difference, but the “early heads” cracked easily if overheated, and there are updated “later heads” that are apparently much more sturdy/tolerant. I also picked up an aluminum two-core performance radiator delivered for $139. It’s about a 30-minute swap.

Hope it helps!

 

[Curious Hound]

over the years as the trucks went to the scrap yard and folks with trucks on the road wanted to replace the engine, all the 2.9‘s got gobbled up.

Oh. How rude!

 

[EasternNC]

Upgrading the radiator is no big deal and cheap insurance. I will do that. I'm pulling the engine from the parts truck today and need to know if I need the wire harness and computer?

 

[Curious Hound]

I believe I would keep the engine, harness and ecu as a matching set.

 

[scotts90ranger]

I don't think much changed on the 2.9L over the years, but a WHOLE LOT changed under the hood in '89 wiring wise with the power distribution box and such, I would keep the wiring with the truck not with the engine, sensors should be the same, both have TFI distributors, the throttle position sensor might be different but you could bolt on the old throttle body...

 

[rusty ol ranger]

His 87 harness will be fine with the 89 engine. Just wont have anywhere to plug the EGR sensor wire or knock sensor wire into.

The 89 ECM will directly replace the 87 ECM, and id recommend swapping them as long as both have the same trans.

 

[lil_Blue_Ford]

Yup, definitely have to use the 87 harness. Unless you want to do a whole lot of wire splicing. I ran into this problem years ago trying to swap a 4.0 into an 88. Everything was fine until I tried to deal with connecting all of the wires on the drivers side. It ended up sitting unfinished until my Choptop needed more power than the 2.9 would give and since that wiring harness was a pretty close match, the 2.9 went in my 88.

The 83-88 trucks (Ranger, Bronco II) used multiple plugs on the drivers side to connect to the chassis harness and dash harness. 89 and up used an entirely different setup for that. At some point the computer also moved from the passenger kick panel to under the cowl.

 

[scotts90ranger]

Yup, definitely have to use the 87 harness. Unless you want to do a whole lot of wire splicing. I ran into this problem years ago trying to swap a 4.0 into an 88. Everything was fine until I tried to deal with connecting all of the wires on the drivers side. It ended up sitting unfinished until my Choptop needed more power than the 2.9 would give and since that wiring harness was a pretty close match, the 2.9 went in my 88.

The 83-88 trucks (Ranger, Bronco II) used multiple plugs on the drivers side to connect to the chassis harness and dash harness. 89 and up used an entirely different setup for that. At some point the computer also moved from the passenger kick panel to under the cowl.

The computer moved in either '93 or '95 I believe. I don't remember looking on the '91 or '92 Explorer I had...

 

[EasternNC]

Alright so im in the process of plucking the engine. I had to take the heat shielding off the passenger exhaust and don't know how I feel about putting it back on. I see it is a warm air supply for the engine, but we know cold air is better for volumetric efficiency. Any reason I need to put it back on?

 

[RonD]

Its actually there for faster warm ups, only used for first few minutes after cold start, so up to you really

It can lower Cold Start emissions, because of faster warm up, so if you have to pass emissions test they may look for it, but real longshot on that one

When engine is cold started computer sets Choke Mode so there is no "efficiency" until engine gets coolant to 140-150degF
These air pre-heaters have been used since the 1950's at least, and often missing after DIY repairs, lol

 

[EasternNC]

So I got the engine out and its now home. Problem is, I didn't know it before hand and my wire harness was cut by the previous owner when he took the top end of the engine apart. Guy was a real idiot. So, I found lots of the harness, maybe I can splice it back but man what a mess. I think a new harness would be better. Can a new one be ordered or do I need to find one from another donor truck?