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Discussion Starter #1
My 1987 Mr2 mk1b (auto) was sitting for a long while. Finally bought a parts car to do a manual coversion, I successfully converted it with no problems.
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I also bought an engine for it that is from a previously running mr2, i do not know what year it was but the engine is a 7 rib with an unknown (to me) ecu. (Lets just assume im mr2-retarded, i dont know sh*?)
What i do know is that after doing the manual conversion, and installing this engine it wont start. (Huge bummer)
All of my relays are good (multimeter tested) as well as my coil pack and any other electrical component you can think of in the starting circuit and fuel circuit. I can jump the starter and it will turn over, but there is no fuel and no fire. I have checked the fuel pump, it is good, i can jump a wire to the blue wire and it will manually prime the system.

The engine came from a running car with an ecu and engine harness, all i did was installed and plug & play. Everything hooked up properly.
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All of the lights and accessories work properly as well. My Mk1b is in excellent shape.

Its like something is just simply telling the car not to run and i dont know where to even begin. I dont know how to chase wires from the ecu and looking at diagrams is dead a*$ exhausting.. especially since all the components are good but nothing is doing its job. Ive even tried the jumper wire between E1 and T on the diagnostic but the engine light doesnt give me anything, doesn't event blink constantly. Im so lost, seriously need help.

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Discussion Starter #3
I needs parts from the auto trans shifter. You still have?

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I bought the car as a shell without an engine, trans, engine harness or ecu. Only 2 things i have left of the auto is the shift line and driveaxles. (Shifter was removed before i purchased)
 

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Hey, so are you using the engine harness from the donor car?

From what I know of the MR2 Mk1, they had two different neutral safeties. The manual trans uses a sensor in the clutch pedal, while the auto used a computer switch tied to the auto trans. I've never seen an auto myself though, so I can't vouch for that.

If you still have the donor car, I'd try to follow the button for the clutch sensor and make sure you pulled everything from that. If I remember, I'll look up the electrical manual in my garage and see how the auto does it.
 

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Discussion Starter #8
Have you tried starting the car with the fuel pump jumped?
Yes, the fuel pump works but that still doesnt fix my no fire problem. Wont start but it does throw the check engine light when i jump the fuel pump.
 

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Discussion Starter #9
Hey, so are you using the engine harness from the donor car?

From what I know of the MR2 Mk1, they had two different neutral safeties. The manual trans uses a sensor in the clutch pedal, while the auto used a computer switch tied to the auto trans. I've never seen an auto myself though, so I can't vouch for that.

If you still have the donor car, I'd try to follow the button for the clutch sensor and make sure you pulled everything from that. If I remember, I'll look up the electrical manual in my garage and see how the auto does it.
I have a donor car (1985mt n/a) but thats where i swapped in the transmission from. The engine and ecu i bought together seperately (which did come out of a running mr2, PO upgraded to supercharged engine.) Nuetral safety switch for auto is part of the engine harness. Clutch safety switch is part of the body harness on manual.
If your suggesting that my car wont send the signals to fire up because it doesnt think its in park then please elaborate on how to bypass it at the efi computer because i do not have the original engine harness for the auto so i cant use the NSS to tell the efi computer its in nuetral because those pins no longer exist in this car due to it having an manual transmission engine harness.
 

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...the fuel pump works but that still doesnt fix my no fire problem...

... Wont start but it does throw the check engine light when i jump the fuel pump...

...please elaborate on how to bypass it at the efi computer ...

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The reason that I asked is that your fuel pump won't start if you are jumping the starter. It uses the start signal to bypass the crash interlock.

That is very strange. There is no connection between the fuel pump and the ECU. This may indicate a bad connection in the power distribution. For example, the fuel pump may be overloading its circuit.

The ECU is not involved in starter operation either. The start signal is hard wired through the safety switches, whether they are on the clutch or the transmission. Also keep in mind that an 85 harness is not compatible with an 87 car. The wiring layout was significantly changed for the 87+ models, including the body penetrations that it passes through.
 

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Are you getting a spark?

NSW comes from the ignition switch on an A/T car, and it actually branches off before the neutral switch.

STA comes from the starter side of the starter relay, and should be present even if you are jumping the solenoid.

Both signals do connect to the ECU, but shouldn't prevent it from starting if not present.
 

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Are you getting a spark?

NSW comes from the ignition switch on an A/T car, and it actually branches off before the neutral switch.

STA comes from the starter side of the starter relay, and should be present even if you are jumping the solenoid.

Both signals do connect to the ECU, but shouldn't prevent it from starting if not present.
 

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Discussion Starter #13
The reason that I asked is that your fuel pump won't start if you are jumping the starter. It uses the start signal to bypass the crash interlock.

That is very strange. There is no connection between the fuel pump and the ECU. This may indicate a bad connection in the power distribution. For example, the fuel pump may be overloading its circuit.

The ECU is not involved in starter operation either. The start signal is hard wired through the safety switches, whether they are on the clutch or the transmission. Also keep in mind that an 85 harness is not compatible with an 87 car. The wiring layout was significantly changed for the 87+ models, including the body penetrations that it passes through.
I beleive this is an 87+ model engine (but*) i also beleive the mr2 it came from was an 85.
IMG_20200107_191746246.jpg

Yet having said that, im not certain of the "looks" or differences of an ecu but i beleive this may be mk1b enging harnes and ecu that was molested to work with an 85. Either that or its and 85 harness and ecu on an 87+ 7rib engine. (Engine Harness does not have a/c connection? Upper tan by finger)
15797584010915806901063806412434.jpg

Regardless of which, i wont be able to run start the car without an mk1b harness? (Or do some pinning changes?)
Ive done research but theres si much to take in, this is my first mr2. Heres a pic of my injectors.
15797586395645076491342653623585.jpg


Thank you men so much for your help, please stick with me until we figure this out, im in love with this car and my wife is ready to see my dreams come true as well. (Shes gonna kill me if i dont figure it out, weve put money in it she wasnt happy about ?)
 

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I seem to remember that the fuel injectors were changed between 86 and 87. The 85-86 fuel injectors used ballast resistors, and I think that the 87+ did not. I don't know if the late fuel injectors will work with the resistors in the circuit. It looks like you have the late fuel injectors on your engine.
 

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Have we tried using the diagnostic port to activate things?

And in regards to neutral, here is a picture of the wiring for the manual vs auto ignition. Pardon the tainted coolant stains, the previous owner used the bgb to hold the blown head.
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So there is an actual automatic neutral safety switch in the car somewhere between M1 and M1.

M1 is the plug you're pointing to in your previous picture. So one of the wires should run off to a unit and just end there. From the mr2.com forum I found a thread that said this:

"Basically, run 2 wires from the clutch safety switch to the auto shifter switch, and 2 wires from the reverse light switch on the manual transmission to the auto shifter switch. "
I don't know if you did that step or not, but it is important to ensuring the car turns on, and has tripped up other swaps I saw on the internet. You COULD short out the switch and be done with it, but if you ever started in gear you'd have some big problems and your dream would end pretty fast.
 

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Discussion Starter #17
Have we tried using the diagnostic port to activate things?

And in regards to neutral, here is a picture of the wiring for the manual vs auto ignition. Pardon the tainted coolant stains, the previous owner used the bgb to hold the blown head.
View attachment 68978

So there is an actual automatic neutral safety switch in the car somewhere between M1 and M1.

M1 is the plug you're pointing to in your previous picture. So one of the wires should run off to a unit and just end there. From the mr2.com forum I found a thread that said this:



I don't know if you did that step or not, but it is important to ensuring the car turns on, and has tripped up other swaps I saw on the internet. You COULD short out the switch and be done with it, but if you ever started in gear you'd have some big problems and your dream would end pretty fast.
Jumping wires on the diagnostic port does NOT work. I cant make the fuel pump kick in through it (as previously stated i can run direct power to it and make it work) and i couldnt get check engine light codes to throw on its on-board system by jumping the E1 and T, it didnt even make the check engine light come on at all.
I will figure out what wire is supposed to be what on the M1 and try jumping them.
ive driven standard vehicles my whole life, i have the "wiggle stick" neutral check hard wired into my system ??
Ill send an update when i can, ive been at it for weeks, if this doesnt change things for me then im just going to wait until i can get an unmolested 87 engine loom to put on it then go from there.
 

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I know I'm following a different thought train than the other parts of this discussion, but hopefully attacking it from different angles will narrow down the problem. Looking up bits about the swap, people have said the M1 plug needs to be bypassed or tied into the new manual harness, which is why I'm following that path.

Here are two threads discussing it: One, and Two.

The M1/M2 plug is that unit that used to have two connectors on it. One should be empty now (M1) but had 10-12 wires on it, and the other should have four wires coming out of it (M2).

M2's wires are Black/White, Black, White, Blue/Black.

M1's wires are in order:
Row 1: 4 Green/Red (Neutral Start to ECU), 3 Green (Neutral Start to ECU), 2 Black (Neutral Start to Starter), 1 Black/White (Neutral Start to Ignition)
Row 2: 8 Blue/Yellow, 7 Brown/Yellow, 6 Purple, 5 Green (entire row is ECT Solenoid)
Row 3: 12 Red/Black (Backup lights), 10 Black/White (Cruise Control to Neutral Start)

From looking at the wiring diagram, you could try jumping the black and black/white wires on the top row of the M1 plug together (Pins 1 and 2), and see if you get a pulse that way. Make sure it's the black wires that have two green wires next to them.

If you have your old Auto harness, cut the M1 plug from there (If you're willing to cut), solder those two together and cap off or de-pin the others, then plug it into the M1 female on the body.
 

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Interesting, that diagram doesn't show the STA signal branch off to the COR to run the fuel pump while cranking.
 
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