When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
You had mentioned your MAF pins were in the wrong place. Can you share some info you learned regarding what pin numbers were in the wrong spot? Perhaps that is my problem as I had to pin these wires in the E7 plug at pins 12, 2, and 8.
You're working with a 97 4Runner 4x4 M/T ECU right? (I think I saw that mentioned somewhere).
For a 97 4Runner 4x4 M/T 5VZ ECU the pins for the MAF are in connector E6 not E7, but are at pins 12, 2, 8 like you mentioned.
Below is a recycled screen shot of a section of that EWD showing the connections to the ECU:
The 3 pins on the bottom of the blue box labeled 'THA', 'VG', and 'E3' are for the MAF. There are 2 circles with a letter in them ('B' or 'F') the upper circle is for M/T ECUs and the lower is for A/T ECUs. Then on the side of the ECU block diagram there's a key that says that connector E6 is abbreviated as 'B' in the diagram. Then the number next to the circle is the pin number.
If you're plugged into the wrong connector, that would certainly cause problems.
If you're plugged into the wrong connector, that would certainly cause problems.
And a LOT of problems for sure. lol Yes, you are correct.. thanks for posting it. I had caught my mistake as when reading the diagram I have at home, I read that the E7 was for the C plug and not the B plug which was the E6 while replying to his post. You must have posted right before I made the edit 45 min after the post as I caught the mistake....or did the edit take hold? hmm. Either way, yes, I have (had) it pinned right, just want to make sure of the connection in the plug to rule the MAF truly defective due to wiring. At last, I can actually read the EWDs!! I'll check the VG (power) wire at the connector for volts of 9-14 and probe the E3 (ground) for continuity tomorrow. If it checks out, it is dead. Oddly the resistance is fine though. hmm
Also, how do you like your Marlin short shifter? My next project after the obvious was to replace my bushings and was considering this shifter. Mine is sloppy as all heck. Does it compare to a regular car MT shift?
Last edited by Oregon'sLoneWolf; 03-05-2015 at 09:20 PM.
I assumed you just read/remembered that EWD wrong vs actually wiring up the wrong connectors, but at times like these, any sort of sanity check is good (just to make sure you didn't do something painfully dumb).
I've been happy with the marlin shifter, it took a couple of weeks for the new bushing to break in (though they claim that isn't needed); all the shifts had much more resistance than I expected. Though now, some 2 years and nearly 20,000 miles I'm still super happy with it, everything still shifts really smooth (except going into 1st when cold, but I suspect that isn't the shifter...either pedal bracket or a tired synchro). Only reason I added the short throw shifter vs just a new bushing was to account for the body lift, the stock shifter with boot wouldn't shift into 2nd or reverse.
I assumed you just read/remembered that EWD wrong vs actually wiring up the wrong connectors, but at times like these, any sort of sanity check is good (just to make sure you didn't do something painfully dumb).
Painfully dumb? There is always chance of that. Living inside my head is one hell of a journey. I just have to laugh at it when it happens. Yes, you are correct. I read it wrong when I was replying. I checked each pin about 4 times last year when I did the plugs. Yeah I could only imagine the functions I could have screwed up had I had made that mistake. lol
Yeah, for the money, I suppose I will just do the bushings. I can have those here in a couple of days as I wait for my Cat, 02 sensors, ICM and MAF to be shipped from Michigan now that the budget allows for it. The MAF was toast after all. Waiting on parts has been killing me!!!!! I don't want to put on the PS pump ect. until I can confirm the timing issues I might be having with the cams. Sure would hate to take it all apart again.................SO...........I patiently wait.........again.
You had mentioned your MAF pins were in the wrong place. Can you share some info you learned regarding what pin numbers were in the wrong spot? Perhaps that is my problem as I had to pin these wires in the E6 plug at pins 12, 2, and 8.
I did not make record of which went to where. Sorry . I just wrote on my arm pin x was actually pin x and etc.
Originally Posted by Oregon'sLoneWolf
Great info. Regarding the ground points. I don't have one in the old battery location as nothing comes off of 97 harness and nothing comes off of the wire loom at the fuse box that I can see. I imagine it would be a ring terminal to a screw. Could this have been an old ground from previous battery location NEG terminal to the sidewall...which would no longer be there? Can you be specific as to where this ground comes from and to where please?
Second, the ground from my alternator to sidewall I didn't add as a part of my 3 big wire upgrades. I put the 8ga wire from the neg to sidewall. Is it necessary that it comes from the ALT? Yes, I would agree this is the better of the two ground points. I did leave the ground from the old ALT harness on the sidewall drivers side with flat large "spade" connector and the ground wire from that to the Manifold bolt on Driver's side. This in addition to the 4ga at the lower engine block seems to work OK. Back of engine to firewall.........CHECK.
The engine harness itself will ground on the intake manifold. Like the 3.0, there should be a ground plug that bolts to the back firewall, located at the top rear of the manifold... Unless it's at a different spot.
The Starter Harness is what has the ground at the battery location. The ground in that harness has the thick wire going down to the frame, and the body ground on the other end that attaches to the side wall next to the battery. Both of these grounds come together to the battery terminal.
Yes the ground off the alternator harness is what I was talking about.
It seems like you got everything in check, just wanted to point that out though. That is why you don't need to ground the ECU box itself. All the grounds coming out of it goes to these spots one way or another and are described in the EWD if you scroll down
Glad to hear the MAF was wired correctly, hope you are having better luck. I have a coolant leak on mine, and have yet to find where it's coming from, and then I was trying to get the idle air valve unstuck, but then I broke the magnet inside lol.
Well, my parts finally came in that include the MAF and ICM. O2 sensors are here and Rock Auto sent the wrong cat back.
I plugged in the MAF and ICM cranked it and got no codes. Not sure why this is happening though.
Still no spark nor start.
The coil connectors show it is getting 12.5 volts.
I checked the crank and cam sensors and coils and they are withing Ohm spec.
The next on the list is to test the IGT signal from the ECU. I pulled the ICU and checked for voltage of the IGF (E5 pin 17) for voltage of 4.5-5.5.................................it was only .705 I think my ECU is TOAST!!!!!!!!!!!!! Seems that every part I got was TRASH! I seem to have the worst luck!
Finding one for my rig is almost impossible!
Anything else I need to check?
Last edited by Oregon'sLoneWolf; 03-18-2015 at 09:28 AM.
I did not make record of which went to where. Sorry . I just wrote on my arm pin x was actually pin x and etc.
The engine harness itself will ground on the intake manifold. Like the 3.0, there should be a ground plug that bolts to the back firewall, located at the top rear of the manifold... Unless it's at a different spot.
The Starter Harness is what has the ground at the battery location. The ground in that harness has the thick wire going down to the frame, and the body ground on the other end that attaches to the side wall next to the battery. Both of these grounds come together to the battery terminal.
Yes the ground off the alternator harness is what I was talking about.
It seems like you got everything in check, just wanted to point that out though. That is why you don't need to ground the ECU box itself. All the grounds coming out of it goes to these spots one way or another and are described in the EWD if you scroll down
Glad to hear the MAF was wired correctly, hope you are having better luck. I have a coolant leak on mine, and have yet to find where it's coming from, and then I was trying to get the idle air valve unstuck, but then I broke the magnet inside lol.
Good to hear you are having better luck than I am......MAF was dead as well as the ICU. Take a peek at my next post......one step forward.......5 steps back it seems...............MY ECU IS DEAD TOO!!! This is killing me man!!
Last edited by Oregon'sLoneWolf; 03-17-2015 at 02:52 PM.
Are you certain you've got the "d12" on your ecu fed with 12v? It's the +B spot and it's most usually overlooked at first. I don't know he plug name on your. E12 on mine.
So get it running on a cheap automatic ECU and then change to a manual transmission computer one day once it's running great. Hate to see you blow $300 and might not fix the problem
Are you certain you've got the "d12" on your ecu fed with 12v? It's the +B spot and it's most usually overlooked at first. I don't know he plug name on your. E12 on mine.
Yeah man, I just checked the pin 12 of the E8 plug for the B+.....12.6 volts.
So get it running on a cheap automatic ECU and then change to a manual transmission computer one day once it's running great. Hate to see you blow $300 and might not fix the problem
I'm really not sure an automatic ECU would work on my rig with the plug pins do you? I think it might have a problem with my 02 sensors as I believe these will have to work with the matching ECU. Since it does come with a warranty, I'll just have to bite the bullet on this one...........thanks for the concern though as it does kinda suck in a huge way. At least I'm able to trouble shoot it......it's learning that just comes at a high cost I guess.
My only question is, why am I getting 12.5 volts on the power wires for the coil connectiors? Or does this IGF have to do with the ignitor sending a signal from and back to the ECU? Hell, doesn't matter as it only has .705 volts.
Last edited by Oregon'sLoneWolf; 03-17-2015 at 03:42 PM.
You got 12V at the Coils because they are getting Power right from the Ignition Switch when the Key is On. The other pin of the Coils is a control wire the controls the coils from the Ignitor. The IGF is probably reading low because the resistors, but like you said it was out of specs.
Like the other guy said, make sure BATT has a constant 12V, and make sure +B has 12V only when the Key is on.
There was another guy on here, that actually took apart his ECU and found a scorch mark on the circuit board which was a burnt out component that caused the truck not to run right. I also checked mine too, just because I got it from Ebay. Only a couple screws and the case comes apart, just be very careful if you do, and try not to touch the circuit board.
Last edited by cr@ves4wheelin; 03-17-2015 at 06:27 PM.
You got 12V at the Coils because they are getting Power right from the Ignition Switch when the Key is On.
Like the other guy said, make sure BATT has a constant 12V, and make sure +B has 12V only when the Key is on.
That makes sense about the coils and the ign switch. I didn't check the BATT for 12v but I guess that would be OK since I am getting 12.5 at the B+ with ign key on. I'll check tomorrow though. After looking at the diagram you are right, must be a resistor. With my luck I would fry it. lol Anyway, I ordered a new used ECU with a 30 day warranty......the project so far is cheaper than a new used truck that would bound to have problems soon after anyway. So far I am into it $3500 with almost new everything.......I can't stop now!
Thanks man!! Well, I had thought I may have aligned the cams with the dots on the sprockets at exhaust at TDC and not compression. Looks like that won't be a future problem as they are lined up on the compression stroke. I'll spend today just putting the rest of the engine together. ECU will be here by Sat I think. I sure would hate to see your coolant leak coming from the H20 pump.
Last edited by Oregon'sLoneWolf; 03-18-2015 at 11:06 AM.
I'll be waiting to see how it goes on Sat.!! Good on you, for taking this project on!! Just remember, be patient, take one step at a time, and you'll get there!
A yr ago I bought my oldest son a $350 car-- to get to work and to teacher him how to maintain a car. I've pulled all the parts he's needed out of the pick n' pull, as it's a waste, buying new parts for a $350 car!! All of the work required I've assisted him, but ensured he's done the lions' share of the work, except for the last electrical problem. He's come a long way.
I'm not sure if it's a great idea to sub an Auto ECU as suggested earlier, more re-pinning would be required!
03-05-2015, 03:26 PM
. I just wrote on my arm pin x was actually pin x and etc.
Well, my parts finally came in that include the MAF and ICM. O2 sensors are here and Rock Auto sent the wrong cat back.
Good on you, for taking this project on!! Just remember, be patient, take one step at a time, and you'll get there!
