Can faulty ecu cause limp mode, rather than maf?

[slidewaysmn]

My s13 redtop swapped in my s14 is stuck in limp mode, and is also not getting a starting priming pulse...could both these problems be caused by the ecu? The MAF is not getting grounded. The maf ground goes to the ecu, which grounds it. Could my ecu be bad? Also why no priming pulse?

[slidewaysmn]

Bump...please.

[opponheimer]

Its the ecu or wiring up to the ecu is bad... I was shipped a bad ECU and it did the same thing you describe. If you want me to checkout your wiring I can.. but you should def. try another ECU. Take apart your current one and smell for burnt parts.

[DirtyS14]

Is that f**king rupert the bear in your avatar?

[GSXRJJordan]

To answer your question, yes it could cause that, but it's not likely. Make sure you have the ECU grounds connected to the car somewhere (intake manifold is OEM location), and pin 16 on the ECU plug goes to MAF signal, pin 17 to MAF ground.

This should help you out ~
http://www.plxdevices.com/ECUDatabas...0DET_91_95.pdf

Remember, that pinout reads from the back of the plug, not the front.

[slidewaysmn]

Yeah, i've gone threw all of my grounds a good 3 times. Re-did a few of the chassis grounds because of the newly painted engine bay. I'm trying to borrow an ecu from someone currently....

[GSXRJJordan]

Originally Posted by slidewaysmn

Yeah, i've gone threw all of my grounds a good 3 times. Re-did a few of the chassis grounds because of the newly painted engine bay. I'm trying to borrow an ecu from someone currently....

Did you do a pin-to-pin on the MAF wires using a continuity tester? Make sure the problem isn't in your harness first... since the fact that you've swapped an SR20 into your car means that you've extended those MAF wires, 99% chance the problem is there.

Also, the MAF signal wire is shielded, and that shield is sometimes grounded - make sure that the shield-wire (silver, tiny strands) doesn't touch the signal wire (copper, larger strands) on the inside.

[shinmei-2006]

Originally Posted by slidewaysmn

My s13 redtop swapped in my s14 is stuck in limp mode, and is also not getting a starting priming pulse...could both these problems be caused by the ecu? The MAF is not getting grounded. The maf ground goes to the ecu, which grounds it. Could my ecu be bad? Also why no priming pulse?

it could be the MAF, MAF wires to ecu, or ecu drivers for the MAF.

[slidewaysmn]

Yeah, the first thing i did was re-check my solders on the portion i used to extend it. I used a shielded wire to extend it also. It may be possible that the metal strands in the shielding are grounding the others....so i'll have to check on that again..