1G Cranks But Doesn't Start

[Bloodman324]

Hello all! I recently picked up two First Gens, a 91 with no motor or transmission, and a 92 with motor and transmission. The plan is to transplant the motor and transmission from the 92 into the 91 for my son to have as his first car. But before we do that I want to get the 92 running so I can drive it over to my dads were the other car is.

I'll start this thread with laying out everything I have done and tested so far and then i'll finish up with the few major questions I have.

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The 92 last ran when it was parked 6 years ago, the bell housing on the transmission cracked so they replaced it with another manual from an Eagle Talon, and after that it got parked and forgotten about since the previous owner got more into trucks. The previous owner also said that there was a fuse inside under the driver dash that you had to do something with to get it to start. He couldn't remember since it was a while ago.

Before I made the purchase I made sure that the car with the motor would run. With a fresh battery and starting fluid it purred to life for a second or two. So it will run on starting fluid. After inspecting the under dash fuse panel, I found that there were three fuses that were so loose they wouldn't stay in the slots. The bad slots are for the door locks (which doesn't make sense because this car has manual windows and door locks), the far bottom left slot which is blank in the diagram in the owners manual, and the far bottom right slot which is for the room lights. I tried to bend the tabs back in place on the room slot and the door lock slot and they both broke off on me, so I'm hoping I'm not fighting the antitheft stuff because of that. I also noticed after I broke those two slots the radio doesn't turn on anymore, but it still cranks and everything else seems to work. Below is what I have done so far to try and get it going again:

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• Fuel Tank has been dropped and rust and gunk have been thoroughly cleaned out
• New Fuel Pump Installed
• Fuel Line has been blown out
• New Fuel Filter Installed
• Fuel Pump works and fuel line and filter have been primed, fuel is getting to the fuel rail
• New Battery Installed
• Checked all fuses and they were good

This car came with three extra ECU's on top of the one that was already plugged into the car. I tested all three ECU's as follows:

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The ECU that was plugged into the car when we got it
MD166262
E2T36578
1410 M
6262

• Fuel pump works
• No Spark
• No CEL w/ Key ON
• No power to injector connector with key ON and cranking - both wires

Extra ECU's
MD166262
E2T36578
0Y21 M
6262

• Fuel pump works
• No Spark
• CEL Light ON w/ Key ON
• Injector connector get 12v on both wires with key ON, voltage drops to 11v on one wire and 10.9v on the other while cranking

MD159561
E2T33674
3Y11 M
9561

• Fuel pump works
• No Spark
• No CEL w/ Key ON
• No power to injector connector with key ON, but while cranking one wire gets .7v and the other gets .8v

MD166255
E2T36572
0Y29 M
6255

• Fuel pump works
• Has Spark!
• CEL Light ON w/ Key ON
• Injectors gets 12.1v on one wire and 9.3v on the other w/ key ON and while cranking voltages drop to 10.9v on one wire and 8.3v on the other

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This last ECU i think is the winner out of them all to get it going, but I am no expert when it comes to ECU's.

So my questions are:

• I've read on here that all 1G's have the antitheft feature, if that's true, is the Door Lock Fuse (even though I have manual locks) and/or Room Fuse on the panel under the driver dash be part of that circuit and therefore I am fighting that because I broke the receiving pins for the fuse on both of those slots?
• If I fix those slots on the fuse panel to get them working properly again, will that allow the ECU to pulse the injectors? I may have power to the injectors with the one ECU but I have no way in knowing if its pulsing or not. I also cannot hear the injectors clicking while cranking with any of the ECU's
• Am I just fighting bad ECU's?
• I also read that the Engine Coolant sensor would cause issues? I think this is the coolant light according to the owners manual, it has been on constant with all the ECU's and testing even though there is coolant in the system:

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• Am I fighting a Crank Positioning Sensor or the CAS? If this is the CAS it looks like the previous owner changed it out along with the coil packs and this piece that I'm not sure of:

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• Would I be better off doing the motor swap into the 91 and then try to get it to run? The fuse panel under the driver side dash is in great shape (as well as the rest of the car). I was going to swap the panel into the 92 temporarily but it had one different connector and the pins were all different on the others so I nixed that idea.
• If I need to do the swap to get it running will I need to transfer over this Black and Grey box under the radio by the ECU? The 91 has the connectors hanging in that area but no boxes or metal brace for the black box.

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I'm not quite sure were to go from here so any help would be much appreciated! Also sorry for the long post!

 

[92AWDHX40]

How To Diagnose A No-Start

Diagnosing a No-StartI've been seeing a lot of No-Start related threads popping up lately, and I figured a basic Tech Article for diagnosing a few of the most common No-Start problems might be in order. Any images posted are courtesy of my 1990 GSX your setup may differ slightly; refer to...

www.dsmtuners.com

 

[luv2rallye]

The fusebox lower right (#19) 10A fuse is both the room and ECU backup power which must be there for the ECU to work.

 

[steve]

Assuming both the 91 and 92 are/were manual turbo federal cars the MD166262 ECU's are the right ones. The other two are not, the MD159561 is for a 1G 1.8L car and the MD166255 is for a 91-93 NA 4G63 MT federal car.

Not all 1G's came with anti-theft.

The infamous "carousel" coolant light is only connected to the sensor in the overflow bottle. The get stuck from all the crud in there over the years and usually need a good cleaning to free them up.

The CEL next to it is the key light right now. It needs to turn on for about 5 seconds after you turn the key on and then go out. If it doesn't you have an issue with the ECU or the circuits powering it. Nothing very interesting will happen until that's sorted.

The car will crank even without an ECU because the starter circuit is independent from it. The ECU gets signals telling it the engine is being cranked but doesn't drive the starter.

If you remove the four screws from the ECU cover the boards for the MD166262 ECU's should look like this. Note that the numbers on the white connector match the last 4 in the E2T number on the cover.

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[TerminalTalon]

I appreciate the long post. It means you’re dedicated to actually figuring it out instead just “why no run?”. We’ll get it sorted. I can try and take some pics of the wiring diagram tomorrow for you.

 

[Bloodman324]

How To Diagnose A No-Start

Diagnosing a No-StartI've been seeing a lot of No-Start related threads popping up lately, and I figured a basic Tech Article for diagnosing a few of the most common No-Start problems might be in order. Any images posted are courtesy of my 1990 GSX your setup may differ slightly; refer to...

www.dsmtuners.com

Thanks 92AWDHX40! This thread had alot of good info!

The fusebox lower right (#19) 10A fuse is both the room and ECU backup power which must be there for the ECU to work.

Thank you luv2rallye! I was figuring that would be the case from the research I've done, but I'm happy to have a solid answer for that. And in regards to that I went ahead and did some backyard mechanics and got the fuse panel fixed and functioning:

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And fun side note, the radio comes on again
Still no start though, but with all this help I feel like I'm closing in on the source.

Assuming both the 91 and 92 are/were manual turbo federal cars the MD166262 ECU's are the right ones. The other two are not, the MD159561 is for a 1G 1.8L car and the MD166255 is for a 91-93 NA 4G63 MT federal car.

Not all 1G's came with anti-theft.

The infamous "carousel" coolant light is only connected to the sensor in the overflow bottle. The get stuck from all the crud in there over the years and usually need a good cleaning to free them up.

The CEL next to it is the key light right now. It needs to turn on for about 5 seconds after you turn the key on and then go out. If it doesn't you have an issue with the ECU or the circuits powering it. Nothing very interesting will happen until that's sorted.

The car will crank even without an ECU because the starter circuit is independent from it. The ECU gets signals telling it the engine is being cranked but doesn't drive the starter.

If you remove the four screws from the ECU cover the boards for the MD166262 ECU's should look like this. Note that the numbers on the white connector match the last 4 in the E2T number on the cover.

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And thank you Steve! I could not for the life of me find any of that info on the ECU's. But knowing all that now it makes sense why all the other ECU's weren't working with the car.

Both cars are 5 speed manuals from the factory and both are non-turbo cars. I'll have to check both VINs to verify that but just from looking at everything it doesn't look like they were swapped or had turbos.

Moving on to the CEL, I can tell you for sure that it does not go out. Key on, it stays on and even while cranking. If it's staying on I'm guessing it has a code stored, possibly keeping it from firing the injectors? If that's a possibility how would I go about clearing the codes without having a reader?

I've tried the key on key off sequence to try and get the CEL to flash but it never does.

I appreciate the long post. It means you’re dedicated to actually figuring it out instead just “why no run?”. We’ll get it sorted. I can try and take some pics of the wiring diagram tomorrow for you.

And thank you TerminalTalon that would be awesome! If I can better understand what I'm working with I can better diagnose the issue.

 

[steve]

Moving on to the CEL, I can tell you for sure that it does not go out. Key on, it stays on and even while cranking. If it's staying on I'm guessing it has a code stored, possibly keeping it from firing the injectors? If that's a possibility how would I go about clearing the codes without having a reader?

I've tried the key on key off sequence to try and get the CEL to flash but it never does.

That's one possibility but fault codes are cleared with the loss of backup power (your room fuse). If per chance the ECU is good and you do have a fault code you can read it using a multimeter, 12v LED, or 12v piezo buzzer. (or a OBD 1 datalogger) by connecting between pin 1 and pin 12 on the OBD 1 diagnostic connector by that fusebox.

1G - Diagnostic testing without a scantool (CEL testing) ~ 1g Turbo models

Is your 1g throwing a check engine light? Here is a simple way to diagnose it without the use of a scantool or diagnostic checker.All you will need is a simple voltmeter. First, locate the OBD (Is right next to the fuse box near the driver's feet).You must be registered to see element. You...

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This is a How-To on figuring out your Check engine light (CEL) for 1g.Tools: Volt Meter or LEDConnection: Connect the positive of the volt meter or LED to pin #1 and the ground to #12 pin on the port. You must be registered to see element.After you got that done, turn your key to the ON...

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If there are no codes you'll get a repeating on/off heartbeat. If you get nothing or a solid 12v there something wrong with the ECU or it's power. Fault codes will be spit out as a series of long and short pulses.

 

[Bloodman324]

That's one possibility but fault codes are cleared with the loss of backup power (your room fuse). If per chance the ECU is good and you do have a fault code you can read it using a multimeter, 12v LED, or 12v piezo buzzer. (or a OBD 1 datalogger) by connecting between pin 1 and pin 12 on the OBD 1 diagnostic connector by that fusebox.

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Is your 1g throwing a check engine light? Here is a simple way to diagnose it without the use of a scantool or diagnostic checker.All you will need is a simple voltmeter. First, locate the OBD (Is right next to the fuse box near the driver's feet).You must be registered to see element. You...

www.dsmtuners.com

1G - CEL LED code flasher

After helping out a member on Facebook with making this code flasher I decided to post it up on DSMtuners for anyone who needs help understanding how to make one of these to pull codes from there 1g DSM (turbo or non-turbo).TOOLS YOU WILL NEED: soldering iron (electrical, or gas heated...

www.dsmtuners.com

1G - 1g Code Reader - CEL CODE READER

This is a How-To on figuring out your Check engine light (CEL) for 1g.Tools: Volt Meter or LEDConnection: Connect the positive of the volt meter or LED to pin #1 and the ground to #12 pin on the port. You must be registered to see element.After you got that done, turn your key to the ON...

www.dsmtuners.com

If there are no codes you'll get a repeating on/off heartbeat. If you get nothing or a solid 12v there something wrong with the ECU or it's power. Fault codes will be spit out as a series of long and short pulses.

Thanks for the info, I went out and tested with my volt meter if there were any codes and all I got was a solid 11.5 volts at pin 1 and 12 on the data connector. I think it's safe to say the ECU is bad. I haven't pulled the cover on it yet, but I'll do that tonight to see if I can find any damage.
Is there a good reputable place i can send my ECU in to get it repaired?

 

[steve]

The only one that I trust since I no longer do ECU work is ECMTuning.
I think I have a good 1G NA ECU on in the basement. I'll look and let you know.