Engine Swap problems

D

dbole

New member
Ok, So I finally got my 98 engine into my 97 4runner, bith are v6 3400 engines. I got it all together and wouldnt start over. Changed the starter as we found out it was bad, but still no joy. I am wondering, could the computer need to be swapped with the engine? Should I put the computer that was in my 98 into the 97 since the 98 engine is now in the 97? The fuole pump runs constantly with power on and the poower windows dont work. Any other suggestions?
Thanks.
 
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Is there any noise or does the engine do anything? the wiring is the same, I'm 98% sure that the computer doesnt matter. I just swapped out my second engine into my runner yesterday and its running just fine.
where did you get the engine? Junk yard or Rebuilt engine?
What kind of test do they do before they sell it?
 
engine swap

jmt2404 said:
Is there any noise or does the engine do anything? the wiring is the same, I'm 98% sure that the computer doesnt matter. I just swapped out my second engine into my runner yesterday and its running just fine.
where did you get the engine? Junk yard or Rebuilt engine?
What kind of test do they do before they sell it?
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The engine came out of my wrecked 98 4runner. The wiring harness and all looks the same to me also. When you turn the key it will make noise and the starter will whine but nothing will turn over. WE jumped the lead from the starter to the battery and it turned over but wouldnt start.
 
Did the engine run before the it was pulled out of the wrecked runner?

You check all the fuses? Do you have spark?
 
yes the engine ran, I drove it from wrecking yard were it was after accident to home , no problems, and drove it into garage before i did the swap
 
ok, what wire connector down by the crank pulley? Maybe if I know the name of it, or where it suppoesed to go, I can check. Its in garage right now and snowing, so going to go out tomorrow look at it. I am sure I did all wire connectors, but... you kno whow it is, look over one thing..
 
Are the '97 and '98 both 4wds? Both SR5 or Limiteds? If not, I believe the computers may be different since some models have push-button 4wd and some don't. If they are the same trim, then I don't think there should be any differences with the ECU or sensors, but I'm not 100% sure because I haven't swapped a 3.4 yet.

I do know that if one is 4wd and one is 2wd, then the computers are definitely different. If I was doing the swap I would have replaced all the sensors on the '98 donor motor with the '97's sensors (along with keeping the '97's ECU) just to be safe. Then there really shouldn't be any issues if it's just a long block swap.
 
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The trim shouldnt matter. I just put a 2000 sr5 motor in my 97 limited and it runs fine. It was 4wd also so I can't vouch for the 4wd and 2wd wiring harness.

Lets start eliminating options.

Did you do anything to the engine prior to putting it in your truck? Timing belt, water pump, change any sensors?
 
both engines came from 4wd sr5 4runners. Both engines are the same and I changed the timing belt and water pump on the 98 engine 6 months before it was wrecked, but no new sensors were put in. I think possibly when the starter arched the battery it may have shorted the ECU. is that possible? the door locks work, but the power windows and heater controls dont. Only thing I can think is either there is short in wiring harness from battery to the starter, or the ECU is fried.
 
my bosses wife has a 4th gen, her batt died, and some "nice guy" decided to give her a jump. he reversed the cables, and caused 3000 worth of damage. they now have a brand new ECU.

maybe that could be the case.
 
noneckrex said:
JMT2404, your like the sherlock holmes of engine issues. (just watched the new one this weekend.)

interesting thread. subscribed!
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That's funny. I just try to help out where I can since I've been in his shoes before and it sucks.

dbole said:
both engines came from 4wd sr5 4runners. Both engines are the same and I changed the timing belt and water pump on the 98 engine 6 months before it was wrecked, but no new sensors were put in. I think possibly when the starter arched the battery it may have shorted the ECU. is that possible? the door locks work, but the power windows and heater controls dont. Only thing I can think is either there is short in wiring harness from battery to the starter, or the ECU is fried.
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Anything is possible. Check the fuse box underneath the hood, there is a big fuse 100 amp i think. It's one of the box type fuses. I had blown that one before and made it not start. BTW its a bolt in fuse so don't just rip it out.

Other than that idk of a way to check the ecu to see if its bad. Put the one out of the wrecked one in there and try it. But I would triple check fuses and connections before you go through the trouble of digging out the ecu and changing it out.
 
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i will recheck all the fuses. I know the ones in the engine block fuse panel are ok, but will also check the big one you talked about. Wil let you know what I find. Im really close to getting this one on the road and want to get it out of my garage, need to work on the wifes Ford escape, which, never get one, they are junk.
 
Also check your grounds on the main wiring harness. I can't remember offhand where the grounds were at, been like 8 months since I did my last 3.4L. I think there was one at the back of the intake, and then maybe one around the oil filter area. There isn't many, I do remember that. Double check each one, to make sure its Tight and making a good ground (clean).
Might try getting the old wiring harness (easier to examine?) and finding each ground location on it first, then double checking each one on the installed wiring harness. I just checked alldata, and it doesn't show squat for ground locations.
If the ECU isn't getting ground, it will not fire. Easy to forget to attach 1 ground.
Then I would start with the basics, check for spark and fuel pressure. Process of elimination.
 
Thats a food point.. Those are the only ones I can think of. The one that goes from the passenger side head on the back to the firewall and then right underneath the oil filter to the wiring harness. There are the other ones on the drivers side intake as well.
 
thnx bigsky, thats one of the first things I am going to check. I know the one on the firewall is hooked up and there is one down by the oil filter that is hooked up also, but will recheck to make sure they are getting good clean contact. The gas cap was not on tight as I undid it when I was replacing engine, and just remembered that, so wonder if that would cause the problem. Will let you all know what I find and post picture of the new beast when I get her running.
 
ok, update. I checked the 2 ground wires and they are good and tight. I checked all fues in the drivers side and in the engine, and all are good. WhenI turn the key I can hear the fuel pump turn on, and there is a hissing noise inside the intake manifold area, not sure what is causing that. Any ideas?
 
Do you have a scanner available? It might of set a code by now, like no crank signal.
Do you have spark?
Hissing noise, key on only? or while cranking only?
 
hissing is with key on and I dont have a scanner. Going to see if I can loan one from the local auto store to see what codes come up.
 
Ok, here is something that I think may be the problem. The fuse box in the engine is different than then 97 in that the 98 has a fuse location marked STA 7.5. Is this for the starter? I thin it is, and if so, how can i go around this without having to replace the whole fuse box. I have the 98 engine and ECU in the 97 body.
 
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