2001 Limited. Wouldn't start after running with no known issues. Was told fuel pump not working so changed it. Cranked and run but then started running very rough (idle), very poor power, and poor gas mileage. Had it coded and came back intermittent missing on all cylinders. Was told to change Crank Shaft sensor. Did that, no change. Then replaced plugs and wires. No change. Had new catalytic converter installed. Change both O2 sensors on exhaust. Had it coded again and came back Mass Air Senor. Changed that, no change. (Took that back and got my $$ back). I'm down to the EMC. I found an exact one (used) and ordered it but now I've been told it won't work without getting new keys. Is that true??? Also, is there anything else on this darn thing I need to check. This 4 Runner has 180k and has been a thing of beauty as far as running great. Just went to heck in a hand basket over night (since the fuel pump). But even someone told me if the EMC is bad or going bad, it could effect the fuel pump so that may not have even been the issue. At my wits end other than taking it to a dealer. Would very much appreciate input and suggestions.
Engine Control Module - Last Hope!
- Thread starter randy5810
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I don't see why you would need a new key. Your ECM part # must match the other ECM your getting. And lets say you got 5vzfe, 4x4 auto. It should say on it, 5vzfe, 4x4 A/T. And I believe it's plug and play. Unless you might need to bring it to delaee to get it flashed to your VIN. Bit I doubt it.
Thanks for the input. Since I already had the glove box and other parts removed to get to the ECM, I went and changed it out. All the numbers on the one I just ordered matched so I'm 100% sure I have the right replacement. However, engine will not crank with the one I just installed. I think it must have something to do with the security system (factory) in the vehicle. So how would this work...can't drive the 4 Runner to dealer with the newly installed ECM. I can drive it with the original one in but will they let me swap it while at dealer? I have no idea of what the "flash" does but I assume it (new ECM) has to be installed in the vehicle? Or is it something they plug into the ECM without it being in the 4 Runner? (I can crank the vehicle with the original ECM, it just runs like crap. But when I put the newer ECM in, it will not crank. Just wanted to clarify the newly purchased ECM is now in the vehicle). From what I've been told, the "Limited" is different from the SR5 and how they are set up with their ECMs. Thanks.
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regardless of what key you are using, it should still crank. It just wont start and run if you dont have it matched up. where did you get the ecu from? Sounds like the one you have isnt compatible. You have to match ECU by production dates as well as model and trim packages ie limited or SR5 4wd or 2wd etc. Also are you using toyota/denso parts? Seems like you are just throwing parts at it from an unreliable source. It sounds like you are probably better off taking it to a mechanic with a good rep or dealer if you dont know of one.
Doc2012
Senior Member
I see a couple things you're missing, and it's not the ECU.
RARELY do the ECUs on these go bad. Trust me. I know.
If I can hose my ECU off, and it run just fine, and AND STILL BE RUNNING, your ECU is fine.
You haven't mentioned changing the coil packs, injectors, or doing any trouble shooting at all, trying to figure this issue out.
Just throwing parts at it hoping it fixes it.
Here's my suggestion.
STOP JUST THROWING PARTS AT IT!
Get down to the nitty gritty.
If you're misfiring, check your injectors, plugs, wires, coil packs.
If you're getting random CELs or codes, search for what they are. Trouble shoot. Just throwing parts isn't going to fix it.
Start from the beginning, anything that MIGHT HAVE happened to your truck to make you think it's the ECU. Hook up the terminals backwards for too long? Get water into it?
RARELY do the ECUs on these go bad. Trust me. I know.
If I can hose my ECU off, and it run just fine, and AND STILL BE RUNNING, your ECU is fine.
You haven't mentioned changing the coil packs, injectors, or doing any trouble shooting at all, trying to figure this issue out.
Just throwing parts at it hoping it fixes it.
Here's my suggestion.
STOP JUST THROWING PARTS AT IT!
Get down to the nitty gritty.
If you're misfiring, check your injectors, plugs, wires, coil packs.
If you're getting random CELs or codes, search for what they are. Trouble shoot. Just throwing parts isn't going to fix it.
Start from the beginning, anything that MIGHT HAVE happened to your truck to make you think it's the ECU. Hook up the terminals backwards for too long? Get water into it?
I pulled the original ECM out of the T4R so when I ordered the newer one, it would be an exact match...and it is. I got it out of CA from a salvage yard. Vehicle it came out of had 59k miles. It could be bad as well, but from what I am told, they don't back all that often. The code print out from the parts dealer showed the ECM as a possible problem so after everything else, I went in that direction.
Well your definition of trouble shooting must be a heck of a lot different from mine. I've been at this for 3 weeks now. Everything I've done has been based on the codes. You are correct...haven't changed the coils. Reason why....Intermittent misfire. Doesn't occur all of the time. I would assume a bad coil would be sending no spark to two cylinders. Two things I forgot I've also done...replaced the battery and check for vacuum leaks. When you get the truck up to top end speed of say 60-70, cruses perfect. Go up a slight incline, you can feel it struggling. Stop at a light...have to put one foot on brake and other on gas as it wants to die. I've trouble shot every imaginable idea someone has given me. I can take it to a dealer...I'm just too hardheaded at this point to give in. Not too many things I can't fix. This one is a little testy. So...what would you do at this point?
Doc2012
Senior Member
Test your injectors.
If you've got an intermittent misfire, good chance it's an injector or two Going bad.
I've got a video somewhere, I'll see if I can find it to show you how to test the injector.
I went for MONTHS battling the same thing, a P0303, P0305, ect ect. Plugs, wires, coil packs.
Turned out two injectors were bad.
I also battled a P0171, and it turned out I had the wrong harness. That was a fun one to try to figure out.....
Give me a call in an hour, and we'll talk through this stuff.
If you've got an intermittent misfire, good chance it's an injector or two Going bad.
I've got a video somewhere, I'll see if I can find it to show you how to test the injector.
I went for MONTHS battling the same thing, a P0303, P0305, ect ect. Plugs, wires, coil packs.
Turned out two injectors were bad.
I also battled a P0171, and it turned out I had the wrong harness. That was a fun one to try to figure out.....
Give me a call in an hour, and we'll talk through this stuff.
Sorry, I'm just seeing your message at 10:00 CST on Tuesday. My DSL went down last night so catching up. Would you have a chance to speak today? I've not taken on the injector as possible cause as I'm not that familiar with testing, cleaning or replacing. So any help would be most welcome. Let me know and thanks for the offer to help.
Injectors for sure.had same issue with a 99 limited,pulled injectors sent out
For rebuild problem solved. ( Conestoga diesel injection lancaster pa) if u mail yours to them they will rebuild and Mail back out same day they get them in,just
Had a set done last week for a 1zzfe rebuild I did for a guy 120.00 bucks for them if I remember correctly it was around 150.00 for 6 injectors, I have 6 injectors out of a 98 sitting in shop with 98 thou miles if you want 25.00 plus ship
For rebuild problem solved. ( Conestoga diesel injection lancaster pa) if u mail yours to them they will rebuild and Mail back out same day they get them in,just
Had a set done last week for a 1zzfe rebuild I did for a guy 120.00 bucks for them if I remember correctly it was around 150.00 for 6 injectors, I have 6 injectors out of a 98 sitting in shop with 98 thou miles if you want 25.00 plus ship
Doc2012
Senior Member
Your '98 injectors are different that the '01 injectors.
Doc2012
Senior Member
They are.
'96-'98 used one set
'99-'00 used a different set
'01-'02 used a different set again.
I know for a FACT that a '98 harness WILL NOT plug into '99 injectors, and, IIRC the '01 harness won't plug into the '99 injectors as well.
Small changes they made to the top end of the motor.
