2G Messed up bad trying to test fuel pump and need help!

[tschuhly]

So I did a very stupid thing today as I was thinking I was putting finishing touches on the car. But as we know man plans and God laughs! I connected the fuel pump test plug to the positive terminal while the key was in the on position. The fuel pump worked for a split second, then a spark, and now nothing.
So far I have determined that the fuel pump works, and when I click to enable fuel pump on ECM link it turns on, with a giant leak at the gas tank but it turns on nonetheless.
I checked all of my fuses and they all seem to be fine. I do have a fuel pump rewire kit with a relay.
Would this mean that I burnt up a wire somewhere prior to the ECU or could it be something else?

 

[chrysler kid]

So I did a very stupid thing today as I was thinking I was putting finishing touches on the car. But as we know man plans and God laughs! I connected the fuel pump test plug to the positive terminal while the key was in the on position. The fuel pump worked for a split second, then a spark, and now nothing.
So far I have determined that the fuel pump works, and when I click to enable fuel pump on ECM link it turns on, with a giant leak at the gas tank but it turns on nonetheless.
I checked all of my fuses and they all seem to be fine. I do have a fuel pump rewire kit with a relay.
Would this mean that I burnt up a wire somewhere prior to the ECU or could it be something else?

You haven’t specifically stated what the problem is. You are saying the fuel pump works with 12v applied directly and works when it’s commanded by the ecu.

 

[tschuhly]

You haven’t specifically stated what the problem is. You are saying the fuel pump works with 12v applied directly and works when it’s commanded by the ecu.

Sorry, to clarify, the fuel pump works with twelve volts straight from the battery and straight to the fuel pump plug where the harness would plug in BUT it doesn't work when using the test connector under the hood that is from factory. When I connect the wire from the plug to the +12V terminal, I can hear things clicking on but the fuel pump no longer clicks on.

You do bring up a good point; did maybe just fry the test plug and nothing else? Unfortunately, I can't test it with the engine cranking yet because I am waiting on my base tune to come back from the tuner.

Also, it is important to make anyone who reads this aware, this is my first project car and although I am confident in my abilities to "figure it out" when it comes to cars, this has been a learn by doing experience. If there is one thing that I severely lack confidence in though...its electrical. All that to say, you are dealing with somebody that doesn't really know much.

 

[jdxnc]

If I'm seeing this correctly, you put 12v to the test terminal on the firewall? I believe it's supposed to be grounded to test the pump. I think you just shorted out the ecu.

 

[tschuhly]

If I'm seeing this correctly, you put 12v to the test terminal on the firewall? I believe it's supposed to be grounded to test the pump. I think you just shorted out the ecu.

I feel like I am not one to debate with a wiseman but all of the research I have done have told me to put 12v to it. Here is a video of someone doing it.

You must be logged in to view this image or video.

As far as the ECU, is it possible that the ECU is shorted even if it still works after being clicked on using ECMLink? I am not sure what I am looking for but I took my ECU out and snapped a picture of it. Let me know if you see anything that looks off. I did notice that it looks like there are two pieces sticking up that resemble glass that look cracked or something.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

UPDATE: as per the linked thread, it appears that the "cracking" is nothing to be worried about. It is a heat sink and there is a coating over them that can sometimes look like this as it ages.

2G - ECU Heat Sink Looks Shattered

I was selling this ECU and I noticed it looks like this heat sink is shattered. The ECU is a 95 Eprom with DSMLink V2 and my car ran fine with it.Does anyone know if its anything to be concerned about?You must be registered to see element.Thanks,

www.dsmtuners.com

 

[DSMPT]

Maybe you applied the 12v to the engine speed detection connector. Are you sure you applied the 12v to the fuel pump check connector? There are 2 connectors in the same location but in different color. IIRC black and blue. The black one is the fuel pump check connector.

 

[tschuhly]

Maybe you applied the 12v to the engine speed detection connector. Are you sure you applied the 12v to the fuel pump check connector? There are 2 connectors in the same location but in different color. IIRC black and blue. The black one is the fuel pump check connector.

I will take a picture of the one I connected to. If I recall, it was a mostly white connecter with some remanence of blue on it and I think the wires going to it were black and blue black. I think it did kick on the fuel pump briefly but then after the spark, it did not any longer. There is a chance that I heard something else and thought it was the pump though.

 

[pauleyman]

If I'm seeing this correctly, you put 12v to the test terminal on the firewall? I believe it's supposed to be grounded to test the pump. I think you just shorted out the ecu.

It is battery voltage. Manual does state with key off. Not sure why it would matter.

 

[jdxnc]

I feel like I am not one to debate with a wiseman but all of the research I have done have told me to put 12v to it. Here is a video of someone doing it.

You must be logged in to view this image or video.

As far as the ECU, is it possible that the ECU is shorted even if it still works after being clicked on using ECMLink? I am not sure what I am looking for but I took my ECU out and snapped a picture of it. Let me know if you see anything that looks off. I did notice that it looks like there are two pieces sticking up that resemble glass that look cracked or something.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

UPDATE: as per the linked thread, it appears that the "cracking" is nothing to be worried about. It is a heat sink and there is a coating over them that can sometimes look like this as it ages.

2G - ECU Heat Sink Looks Shattered

I was selling this ECU and I noticed it looks like this heat sink is shattered. The ECU is a 95 Eprom with DSMLink V2 and my car ran fine with it.Does anyone know if its anything to be concerned about?You must be registered to see element.Thanks,

www.dsmtuners.com

I could very well be wrong, that's why I said "believe" . A LOT of stuff is ground activated, been a LONG time since I messed with oem test plugs.

 

[tschuhly]

Totally get it I appreciate any input that is given!

Here is a picture of the plug that I used to test, and it looks like it is the only plug on the harness in this area that I could find which seems odd.

As it turns out... I must have applied 12v to the speed detection connector...
I, 1, feel like an idiot .
and 2, hope that I did not completely screw something up so is there a way to double check that I did not? I am not even sure what this plug does.
and 3, why would my harness not have the test plug for the fuel pump?

You must be logged in to view this image or video.

 

[jdxnc]

Totally get it I appreciate any input that is given!

Here is a picture of the plug that I used to test, and it looks like it is the only plug on the harness in this area that I could find which seems odd.

As it turns out... I must have applied 12v to the speed detection connector...
I, 1, feel like an idiot .
and 2, hope that I did not completely screw something up so is there a way to double check that I did not? I am not even sure what this plug does.
and 3, why would my harness not have the test plug for the fuel pump?

You must be logged in to view this image or video.

Tan - timing ground plug. You remove the cap and ground the pin if you would need to check your timing with a timing light. It was only found on '95's I believe (not sure about '96, but definitely not '97-'99).

Blue - engine speed test connector

Black - fuel pump test connector

[RESOLVED] What are these plugs on the firewall?

I was doing some emission things when I got off work today and found these three plugs just chilling. What are they for and should they be plugged into something, my car has been acting so funny lately so maybe just maybe a chance? A hope!

www.dsmtuners.com

 

[DSMPT]

2, hope that I did not completely screw something up so is there a way to double check that I did not? I am not even sure what this plug does.

That allows you to connect a engine speedometer to read the engine RPM under the hood.

3, why would my harness not have the test plug for the fuel pump?

Isn't there a black one wire (black/blue) connector around there? You should look for that.

 

[pauleyman]

I could very well be wrong, that's why I said "believe" . A LOT of stuff is ground activated, been a LONG time since I messed with oem test plugs.

Me too. I had to look it up.

Totally get it I appreciate any input that is given!

Here is a picture of the plug that I used to test, and it looks like it is the only plug on the harness in this area that I could find which seems odd.

As it turns out... I must have applied 12v to the speed detection connector...
I, 1, feel like an idiot .
and 2, hope that I did not completely screw something up so is there a way to double check that I did not? I am not even sure what this plug does.
and 3, why would my harness not have the test plug for the fuel pump?

You must be logged in to view this image or video.

The pic you show looks correct. If that's not your car I had heard sometimes 2g cars didn't have it. Thought it was only some 95s. Could have something to do with the obd2 switchover and a harness manufacturer. Your 97 should have it.
This is also why I verify the plug and wiring colors with the factory manual. Has everything you need to make sure.

 

[tschuhly]

That allows you to connect a engine speedometer to read the engine RPM under the hood.


Isn't there a black one wire (black/blue) connector around there? You should look for that.

I can look again. It wouldn't be wrapped in the wire loom right? It should be wrapped like that one I assume.

The pic you show looks correct. If that's not your car I had heard sometimes 2g cars didn't have it. Thought it was only some 95s. Could have something to do with the obd2 switchover and a harness manufacturer. Your 97 should have it.
This is also why I verify the plug and wiring colors with the factory manual. Has everything you need to make sure.

I bought this car 2 November so and it came with a bunch of extra stuff and was clearly tampered with (i.e. it has a 4g64 trans installed even though it came with both a GST and an evo 3 trans). I assumed it was the harness that was for the car but it is certainly possible that it was swapped prior to me receiving it.
I feel like I do recall seeing some plugs that were unused it something.

 

[DSMPT]

I can look again. It wouldn't be wrapped in the wire loom right? It should be wrapped like that one I assume.

I am not sure but perhaps it has been relocated or cut by the previous owner. The black/blue fuel pump check connector's wire should come from the same bunch as the engine speed detection connector wires, so if you would trace those wires you may find it around there.

The fuel pump check connector is the black one in the green circle.

You must be logged in to view this image or video.

 

[pauleyman]

I am not sure but perhaps it has been relocated or cut by the previous owner. The black/blue fuel pump check connector's wire should come from the same bunch as the engine speed detection connector wires, so if you would trace those wires you may find it around there.

The fuel pump check connector is the black one in the green circle.

You must be logged in to view this image or video.

Hiroshi, its been so long since I looked at these. If I recall besides those two there is a 3rd connector to ground for isc and timing and its got a cap on it? Cant remember if this is true for 2gb but I think it is.

 

[steve]

If it was the Engine Speed Detection Connector, applying 12v will backfeed to the ignition switch and all it's branches but the serious issue is the PTU. It's not designed to get battery voltage on pin 8 without some form of current limiting, so if it attempts to fire the coil while it's connected like that it will burn up that power transistor.

Normally, it's the resistance and inductance of the ignition coil that limits the current but connecting the connector to the battery will effectively be a short to ground when the transistor switches.

You must be logged in to view this image or video.

 

[DSMPT]

Hiroshi, its been so long since I looked at these. If I recall besides those two there is a 3rd connector to ground for isc and timing and its got a cap on it? Cant remember if this is true for 2gb but I think it is.

Paul, I could be wrong, but in my memory, 1g and 2ga (maybe only early 2ga) is the ones that have that connector to ground to set the base timing. My 2g is 98 gsx and I don't see it.

 

[tschuhly]

If it was the Engine Speed Detection Connector, applying 12v will backfeed to the ignition switch and all it's branches but the serious issue is the PTU. It's not designed to get battery voltage on pin 8 without some form of current limiting, so if it attempts to fire the coil while it's connected like that it will burn up that power transistor.

Normally, it's the resistance and inductance of the ignition coil that limits the current but connecting the connector to the battery will effectively be a short to ground when the transistor switches.

You must be logged in to view this image or video.

Yeah, this sounds bad.

I understand a lot of what you said but what would be a good way of checking to see if I damaged any of this stuff? I'm assuming just turn the engine over when I'm able to and see if it engages the spark plugs?

 

[steve]

If it's fried because if this 1 and 4 are the one most likely not to spark.

 

[tschuhly]

I will see what happens. First, I gotta get that fuel leak fixed though!

I really can't thank all of you enough! I would have been completely lost so many times with this car if it wasn't for you all that have been with me and helped along the way! You truly are life savers and it may seem like you are just typing on a keyboard at time to you, but I can honestly say that you have relieved so much stress for me and helped to keep this build fun!

 

[chrysler kid]

Sorry, to clarify, the fuel pump works with twelve volts straight from the battery and straight to the fuel pump plug where the harness would plug in BUT it doesn't work when using the test connector under the hood that is from factory. When I connect the wire from the plug to the +12V terminal, I can hear things clicking on but the fuel pump no longer clicks on.

You do bring up a good point; did maybe just fry the test plug and nothing else? Unfortunately, I can't test it with the engine cranking yet because I am waiting on my base tune to come back from the tuner.

Also, it is important to make anyone who reads this aware, this is my first project car and although I am confident in my abilities to "figure it out" when it comes to cars, this has been a learn by doing experience. If there is one thing that I severely lack confidence in though...its electrical. All that to say, you are dealing with somebody that doesn't really know much.

You still have not described a problem.



unplug the pump and put a volt meter to the wires on the pump to see if it’s getting 12v while cranking.

Honestly I’ve never tried to use the test jumper. There are 2 or three of them around the injector resistor box and it’s just easier to pop out the back seat and get at the pump itself for diagnostics.