Resolved No injector pulse with noid light

[92bushi]

Ok yall. I have a 1992 eclipse gst pushing 350hp. I've been chasing this issue for days now. I've replaced the ecu with multiple new ones. Changed the cas multiple times with different ones. Checked grounds and I've got fuel pressure. Runs great on ether. And sometimes it'll start an run fine. But 20 minutes later it starts then dies within 1 or 2 seconds. New spark plugs as well.

Can't seem to find the injector relay but due to its temperamental nature of sometimes running fine I don't think that could be it. I'm completely lost and confused on what could cause this.

Thanks in advance

 

[steve]

That's a lot of stuff to be swapping.

What injector relay are you talking about?

The Injectors get power from the MPI Relay (Pins 4 &5) just like the ECU and most of the sensors and solenoids do. On a turbo car that power runs to 4 injector resistors used for current limiting mounted to the firewall and from there each to one of the 4 injectors. The ECU pulls the other side of the injector low to fire the injector. On the Non-Turbo cars the power from the MPI relay goes directly to each of the injectors.

All the magic happens inside the ECU.

Do you have the wiring diagrams for your car?

 

[92bushi]

That's a lot of stuff to be swapping.

What injector relay are you talking about?

The Injectors get power from the MPI Relay (Pins 4 &5) just like the ECU and most of the sensors and solenoids do. On a turbo car that power runs to 4 injector resistors used for current limiting mounted to the firewall and from there each to one of the 4 injectors. The ECU pulls the other side of the injector low to fire the injector. On the Non-Turbo cars the power from the MPI relay goes directly to each of the injectors.

All the magic happens inside the ECU.

Do you have the wiring diagrams for your car?

I don't have any diagrams whatsoever for my car. They seem difficult to find and the ones that claim they are don't match up with others claiming the same thing. It's a turbo car. Would the resistors be the cause of this?

 

[steve]

Lets just start with this diagram and then you can go get the links for the FSM elsewhere on the site.

 

[92bushi]

Lets just start with this diagram and then you can go get the links for the FSM elsewhere on the site.

Sweet. Thank you. One more question. This all started without any logical reason. It started and ran great. Them it was trailered maybe 20 minutes and them wouldn't start after the trailer ride. And that's where these issues began. Is the like a fuel cutoff switch. Antitheft. Or inertial switch somewhere. Some places say there is and some say there isn't

 

[steve]

Does you car have either the factory antitheft or an aftermarket alarm?

 

[92bushi]

Does you car have either the factory antitheft or an aftermarket alarm?

Not that I'm aware of. It's got an aftermarket key fob tho

 

[AWD-Tony]

Good chance it has/had an aftermarket alarm at one point then.

Inspect the wires and connector to the coolant temp sensor. Once that’s been ruled out, test the coolant temp sensor.

Edit: Not sure if that would cause no injector pulse.

Courtesy of Steve
Post in thread 'Cold out side harder to start'
https://www.dsmtuners.com/threads/cold-out-side-harder-to-start.535858/post-153819238

 

[Diamond Star Werks]

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[Diamond Star Werks]

Did you check that your injectors have power? When not firing? Ecu controls ground signal but power should be constant with key on. Verify cam/tdc sensor is actually puling down to zero on the white wire and the black wire.

 

[92bushi]

Did you check that your injectors have power? When not firing? Ecu controls ground signal but power should be constant with key on. Verify cam/tdc sensor is actually puling down to zero on the white wire and the black wire.

Yes. They are getting power. And sometimes work. And then sometimes they don't

 

[92AWDHX40]

Yes. They are getting power. And sometimes work. And then sometimes they don't

Could be a wiring issue if it is consistent.

 

[92bushi]

Ill

Could be a wiring issue if it is consistent.

I'll double check em. It seems more at random tho. I'm jus so confused on what it could be. I've exhausted everything looking for this issue

 

[1990TSIAWDTALON]

Good grounds to the motor? Sometimes they are overlooked is why I bring it up.

 

[92bushi]

Good grounds to the motor? Sometimes they are overlooked is why I bring it up.

Yes. Got that issue figured out. Now my bov is opening at 5k and only in 2nd and higher gears not allowing my to build boost

 

[1990TSIAWDTALON]

So what was the issue so we can all have an answer to refer to and call this thread resolved?

 

[Mech Addict]

Agreed! end the suspense….

 

[1990TSIAWDTALON]

I was fighting a run but NO POWER issue on my DD Saturn after a clutch change this last week and here is what I found and it immediately fixed my problem.
Even though I PREACH about good grounds all the time, I had missed one, and a very IMPORTANT one. It grounded the Ignition Control Module.
See the pic. This isn't on a DSM but is just as important on ANY car.
I would REALLY LIKE TO HEAR the solutuon to the OP's issue so ALL can have the answer, which is what this forum is all about.
Check your grounds people, even I am not immune!!!
Marty

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[92bushi]

I would REALLY LIKE TO HEAR the solutuon to the OP's issue so ALL can have the answer, which is what this forum is all about.

We had some gaps in the tune since I reflashed the computer. Got that figured out. Now my blow off valve isn't holding any boost

 

[1990TSIAWDTALON]

Thanks for the follow up!!! It is greatly appreciated!
Marty