ECMlink Car wont go above 1500 rpm (resolved)

[SnowmanFD]

So i recently purchased a 90' ecu with link from rix racing, i was thinking it might be used and have someone elses tune so i wanted to reset it. I followed scott lairds guide for "new installation for new users" and "resetting ecmlink back to stock" i was able to copy everything BUT the fuel tab but after i compared the current and the factory table they were the same (i think) i went to drive like normal and anytime i got to about 1500 rpm the car would jolt forward like i was still learning to drive stick (even with clutch completely out) after reviewing the log it looks like my fuel flow suddenly drops to zero. i cant upload the logs at the moment but i will take some photos
Side note: "device type" under configure was set to 2g dsm connection, changing it did nothing

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[SnowmanFD]

Something else i though of what would cause a 90 car to run good with a 94 ecu but bad with a 90 ecu? (94 only has a eprom, no link) im going to try pluging in the old ecu and see if it still runs the same

 

[habitatguy187]

Upload an actual log file so that we can go through the settings.

For your question about the 94 working the in 90, either they modified the 94 ecu or they modified the car to accept it.

 

[AWD-Tony]

I see the tps needs adjusting but yeah. Post a log

 

[gavingsx]

When switching between a 90 ecu and 91-94 you must switch pins 14 and 6. That may be your problem.

 

[SnowmanFD]

first one is my first ever start with link and the second is when i saw the fuel issue on the side of the road
gavingsx: that's part of the reason i bought this ecu is because its a 90' i thought because the tach didn't work sometimes the pins weren't swapped
tk's9d2TSi: i also had a dtc for throttle circuit or something like that but it disappeared after turning the car off

 

[gavingsx]

The two pins are for the idle switch and airflow sensor active filter reset. Nothing to do with the tach. You can verify if they have been swapped by the wire colors. If it ran good with the 94 ecu then i bet the pins were swapped. https://www.dsmtuners.com/threads/90-with-91-94-ecu.355082/
post #2 has both the diagrams.

 

[pauleyman]

If the ecu thinks idle switch is closed all the time, suggested by the last post, the car will never exceed 1500 rpm. Ecu cuts fuel at 1500 rpm when idle position switch is closed. It's the same thing that causes idle surge.

 

[SnowmanFD]

Correct me if im wrong but it looks like they are not swapped.
Also i plugged the 94 ecu in and the car runs "fine"

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[gavingsx]

Its hard to tell. Trace the red wire back and see if the colors match. Looks like the cut the wire a soldered instead of pulling the pins out.

 

[pauleyman]

You don't even need to go that far. Just watch the ips in link and see if condition changes.

 

[SnowmanFD]

You don't even need to go that far. Just watch the ips in link and see if condition changes.

See if condition changes when i do what?

 

[gavingsx]

Open up a log in ECMLINK. Make sure you are logging idle switch. See if it changes when you press on the throttle.

 

[SnowmanFD]

I did some rough tracing of all the wires and found this, i havent followed the specific wires yet but i have a feeling this is them

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[SnowmanFD]

Open up a log in ECMLINK. Make sure you are logging idle switch. See if it changes when you press on the throttle.

Should i start the car or just put it in the on position?

 

[gavingsx]

Doesnt need to be running. Just put it in the on position.

 

[SnowmanFD]

Ok ill be home in about 20min and try that. I looked at the photos of my old logs and its saying IdleSw: 1-

 

[SnowmanFD]

Doesnt need to be running. Just put it in the on position.

 

[steve]

IPS never switches and you get a 14 DTC fault because of it. Try switching those two pins,

 

[SnowmanFD]

IPS never switches and you get a 14 DTC fault because of it. Try switching those two pins,

Is there a correct way to swap them thats not cuting it?

 

[pauleyman]

Is there a correct way to swap them thats not cuting it?

Took 10 sec for me to find this.
Search a question on Google
Add a period then add the word dsmtuners. Usually gets good results to this site etc.

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[SnowmanFD]

Took 10 sec for me to find this.
Search a question on Google
Add a period then add the word dsmtuners. Usually gets good results to this site etc.

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Thats normally what i do idk why i thought this would be any different. I apologize.

 

[pauleyman]

Thats normally what i do idk why i thought this would be any different. I apologize.

No need. Just trying to provide support

 

[steve]

Is there a correct way to swap them thats not cuting it?

Based on your pictures it looks like the PO put connectors that just pull apart so you can unplug them and swap. That's what those blue crimps look like to me.

Normally I do what Paul showed. It takes me about 30 seconds to do it but I know what I'm doing and have Jewelers screwdrivers to release the pins.

 

[SnowmanFD]

Based on your pictures it looks like the PO put connectors that just pull apart so you can unplug them and swap. That's what those blue crimps look like to me.

Normally I do what Paul showed. It takes me about 30 seconds to do it but I know what I'm doing and have Jewelers screwdrivers to release the pins.

You would be correct i just unpluged them and swapped them, car runs with the new ecu, AND the tach finally works!!!
Thanks so much everyone for all the help