eriklgordon

I have an 88 sr5 v6 with a blown motor. I bought a motor from a 91 truck (v6). I have the chilton guide, but I am confused on the wiring... (not sure whats what, which wires do i use the ones from the old motor or new or does it matter? Any links w pictures or diagrams or info would be of great help! Ive noticed there are a few differences in the 2 wiring harnesses. I am a beginner mechanic so REALLY any tips would be awesome, but like I said I am most confused on the wiring other then that Im pretty sure i have all the tools I need. PLEASE HELP

SEAIRESCUE

Put the engine in and lay out the wiring harness. If you did not take photos before stripping down the motor, as well during the process, shame on you.
We can't tell you with text how to connect what you have. Make an honest effort to connect every connector then come back with photos. I found a great site about a year ago on the internet that had tons of wiring information. It was a person's experience like yours. It may have come from this site or Pirate. If I find it I'll post it.

My $0.02

eriklgordon

thanks for the info. I haven't gotten very far at all but I have been taking pictures at every step. Going to go look it over w a buddy ill get back w my progress and pics.

MonsterMaxx

You should be able to just lay the harness in place and wire it up, the connections only go to one thing, it's not like you can mix plugs.

The only 'gotcha' I can think of is that I think there was a change in the knock sensor wire somewhere along the way and you have to pull the lower manifold to change it.

Don't worry if the injector plug latches broke off, just zip tie them in place.

Otherwise, you should be good to go.

Ganoid

There is a change in Fuel injector resistance as well. The Injectors in my 90 are high Imp (10-13ohm) but the injectors in my spare parts motor are low Imp (2-3ohm). Prior to my recent researching of larger injectors for my future snail power addition I had no idea there where different values for the 3vze. Just make sure the resistance values are in the ball park unless your swapping the ECU as well.

eriklgordon

Just to let u know about where i am, I still havent unplugged the old broken motor yet, I think Ive got about 6-8 more to disconnect/ label. I am very SLOWLY but surely locating plugs unplugging and labeling them but one section I cant figure out is how/where to unplug the main wiring harness ( 4 main plugs on new motor) see pics do I have to take my whole dash/ heater off to unplug them?

Elvota

You should be able to access the ECM and related plugs by removing only the lower PS kick panel.

eriklgordon

... where can I find the ps kick panel, inside the cab or behind the wheel well..or?

Vohaul

its under the glove box, inside the cab...in front of the door..i think its just has a plastic thumbscrew like thing holding it in

eriklgordon

Sweet I have made some good progress. I have most of the correct electrical connectors unconnected and labeled, just not the few that follow the transmission and transfer case down, ill get those later. One thing I did notice is the difference between the two motors ecm connectors: The 88 3vze has 6 on the side behind the ps kick panel ( 4 that plug into the ecm itself and 2 that plug in near and they are yellow in color. the ones on the 91 3vze are gray in color and there are only 4 of them. I am guessing I should use the wires from the 88? Thats going to be an issue in the next few days...As for tonight I have moved onto the hoses and I am almost done. Tomorrow Hopefully get the motor out! Again thanks for all the help , any additional info is greatly appreciated!
-Erik

DeathCougar

iTrader: (23)

You have to reuse the harness from your 88. Otherwise your truck will not run, trust me on this one.

You also will need to use the motor mounts from your 88, the injectors, etc etc. The only thing you should be using from the 91 is the long block (valve covers to oil pan) and perhaps the lower intake, if its the same. But be aware of things like sensors, rear water crossover pipe, etc etc. Compare compare compare!

You dont want to put it all together, then have to fix/remove parts once you have the engine in.

eriklgordon

Thanks for the heads up.. but by etc etc what do you mean exactly... is there a thread or site to walk me through the process, pictures and diagrams as well. thank you!

DeathCougar

iTrader: (23)

Just anything on the engines that are not the same.

Oh, and replace the Knock Sensor and wire. You'll thank me later.

eriklgordon

so I have to replace(switch) the injectors..., does that mean i pretty much have to take both engines apart? cylinder head , timing belt etc etc? any other huge obstacles (swaps)i should know of besides the injectors? thanks

Ganoid

Check the resistance across the two terminals on one of the injectors. If you have similar values on each motor then you are fine with the injectors in either motor. If you measure motor "A" and find injectors measuring 10-13 ohms each and motor "B" has them measuring between 2-3 ohms each you need to use what ever injectors match the computer in your truck (ECM). You should be able to check 1 or 2 injectors with out taking anything apart and that should tell you what you need to know.

DeathCougar

iTrader: (23)

no you dont have to take the engines apart. Like i said the long blocks (ie heads, valve covers, intake, timing components, block, internals, pan assuming its a 4x4 to a 4x4, etc) are the same

The plugs will be different between 91 and 88 for the injectors, so resistance wont matter. You cant use the 91 injectors in your 88.

eriklgordon

I get the part about using the 88 injectors, just not sure how to get them out... ,Ill do some reading and get back to you. Thank you.

leiniesred

We've done this the other way. 88 engine into 91 truck.

the sensors are all different too. Wound up swapping everything from the lower intake manifold up. The upper intake, plenum, water lines, etc. and yes, we had to do it all over again to replace the knock sensor wire.

eriklgordon

OK so I ve got a multi meter to check the injectors resistance, but i don't have a clue how to use it or where to check the injectors. Any info would be awesome thank you.

MonsterMaxx

What we are all telling you is to use ALL the electronics from the same year.
Some stuff you can get away with mix & match, others...not so much. Since you are a bit of a newbie on the 3.slow and will already have enough challenges, you might as well make it easy on yourself in the electronics dept.

So if you have an '88, use EVERYTHING electronic from the '88.
Knock sensor (replace the wire)
distributor
TPS
AFM
Injectors
etc.

You have to pull the upper plenum to be able to remove the motor.
DO NOT disconnect it from all the vac lines. Just put a towel up on the cowel and lay it gently up there out of your way.
Once you pull the upper plenum off you'll see the injectors. Undo the crossover lines (the lines that go from one rail to the other), then undo the bolts for the rails (keep these seperate and don't loose the plastic bushings.)
Lift the rails off, then you can change the injectors.

If I were you, I'd take those '88 injectors and ship them off to witchunter. He'll check them out cheap and if anything is wrong he can fix them. Prices are reasonable, he's quick and real nice to talk to on the phone. Highly recommended.

OK, now you can pull your 88 motor.

Before you go throwing the new motor in, you might want to do some stuff to it while it's out like changing the timing belt/pulley.

Also take your radiator down to a radiator shop and have it cleaned. Take the oil cooler off the side of the block and have them do it too.

Put the 88's knock sensor in (you need to pull the lower half of the intake manifold to do this so you'll need some gaskets too.) Don't forget to use a NEW knocksensor wire.

Put it all back together and drop it in. That should be about it.

If you have a clutch, now would be a good time to replace it. Strongly reccomond the Marlin Crawler set. WAY better and very reasonable price. Forget the Centerforce dual friction = overpriced POS.