SR20DET swap, no fuel pump prime, no spark, wiring correct

[BlackZ28629]

So, I finally dropped the SR20 in and the damn thing won't start. The starter turns the motor over but that's it.
When I turn the key on, the fuel pump doesn't prime. I've tested all related wiring (wires at pump, relays, etc.) and it's all right/good. I can jump it throught the relay and it works (plus it's brand new and worked before the swap). I followed FRsports wiring guide and checked continuity from there to ecu and it's all good (no broken wires or bad connections). All wiring and relays (EGI, EGI pump, etc.) are working.

I have checked the following pins on the ECU:
Constant Power: #46 and #109 GOOD
Switched Power: #38 and #47 GOOD
Grounds to ECU: #13, 39, 48, 107, 108, 116 ALL GROUNDED when key off
Weird thing is this: I have continuity for the ECU ground with key off, but when I turn the key to ON position, ground goes away. Is this normal? I haven't seen anyone else mention anything like this on any forum, but I realize that the ECU controls some grounds so didn't know if that was normal..seems fishy to me.
But, with that said, I do have all good grounds on the motor as far as I know (one on intake for battery, one on back of head, the coil packs ground, and the two that bolt onto the intake manifold closet to firewall). I took a dremel and cleaned the contacts well before putting them on.
Also, the red LED light on the ECU does not come on. Is it suppose to come on when you turn key on? I tried to put it into diagnostic mode and no light either. My initial assumption is that the ECU is dead, but I opened it up and it looks good inside. Also, when I crank I hear a relay click on and the radio power is lost, is that normal? I don't remember if it did that when stock motor was in.

Anyone have any ideas? I am stumped.... Ready to beat my head into a wall after all this time and $ and no startup!

[BlackZ28629]

Just checked the CAS ground and the ignitor grounds found this: they are grounded (continuity to ground) when key is off, but when I turn the key ON, the ohms jump up to 90ish and lose continuity...Is there a relay somewhere I am missing or does the ECU send the grounds to these?
Also, I ran a ground straight from the battery to the ECU pin 39 grnd and still no change.

I'm still thinking it's probably a dead ECU, anyone???

[BlackZ28629]

Update:
Found the culprit that's taking continuity from the grounds! The big grey plug that is correct according to frsport's wiring guide (mostly ignition wires-black/red, blue/red, black/yellow, black/white, red, green/yellow, blue/green). Now why would any of these break the ground continuity? I don't know. Do you? I don't know anyone who knows how ecus work but I'm still guessing the ecu might be bad..please chime in if you know something. Oh, and I regrounded the chassis and motor directly to the battery to ensure strong ground.

[OM3GA]

A strange thing that has been happening lately and causing major problems is that some people have not tightened the ECU connector down properly. If this thing is not 100% perfect it will not work. I did a whole bunch of testing on my car as well as a friends who was having a similar issue. We thought the ecu's were bad but they were not, make sure that connector goes on straight and is fully seated. If you want to take a picture of it and post it please feel free, i can tell you if it looks fully seated or not. We were getting all kinds of strange readings on sensors etc and it was all from that connector not being properly seated.

Good luck!

[BlackZ28629]

I'm pretty sure it can't be any tighter without breaking...Also, this car is SOHC chassis so I don't know if that makes a difference...I also have an extra plug near the ecu, it's white plug with grey foam insulation around it, but there is nothing for it to plug into...the original harness didn't have that..what is it? Anyways, I also unplugged the connector from the ECU and the grounds lose continuity even with it unplugged...weird. There are no grounds on the grey plug and like I said, I followed the FRsport guide so it should all be right unless something is wrong in the chassis (but it worked perfectly before swap). I am about to go snip each wire until I figure out which one causes the continuity loss. Can anyone please go out and check your 62 ECU to see if the LED light comes on with key? Also, could you check the ground (any of them) for continuity, leaving a meter on it (beeping or whatever) then turn the key on to see if it loses continuity? I want to know if this is normal. Thanks.

[BlackZ28629]

Just checked the grey plug:
The wire that makes the ECU lose continuity to grounds is the main ignition wire (Black w/red stripe)
I have it hooked as follows:
From KA chassis:Black w/red stripe to: SR harness Black w/red stripe (main ignition), Blue w/red stripe (coil pack power), and Brown (supposedly 02 sensor power).
Now, when I turn key on it clicks the EGI relay and send power to ECU (even though I can't see it on or working, voltage is there). Even with that relay taken out, the grounds lose continuity. I feel like I'm getting closer, but still can't exactly put my finger on why that's happening. AND I don't know if that's how it's supposed to be...Thanks for all your considerations!

[BlackZ28629]

Happy New Year to everyone! Please leave any comments if you have any relevant advice or whatever... I ordered another ECU so hopefully that's the problem! It was ridiculously $$$$. Have fun and be safe tonight!

[BlackZ28629]

It was the ECU, got the other one in today, and snap! She fired up! What a good feeling!!
Now to make it run smooth...it has a bit of a sporadic idle, but that's probably due to my intercooler pipe couplers being too short...gotta get some longer ones! I'll keep ya updated on what's happening! Thanks! Cheers!

[Hijacker]

Don't count out the IACV being a culprit. It's a pain in the rear to deal with while the motor is in the car, but if your couplers don't solve the issue, try cleaning the IACV.

[BlackZ28629]

Idles steady now, just idles way too dang high. I cleaned the IACV before I dropped the motor in. Are there any adjustments on it? I am gonna try to adjust the idle screw to see if that helps. I just took her out for a test spin! Runs good, but the transmission didn't like going into 3rd..hopefully that clears up-it is cold and that was the first time I drove it. I put 2.5 qts. gear oil in, should I try putting in the remaining half quart? Also, do you guys run 4 qts. of oil or stick to 3.5? Thanks!

[BlackZ28629]

Update:
When car warms up, it idles at about 800-900 RPM so that's good. Unfortunately, 3rd and 4th grind a little especially on downshifts after the car is warm. Weird thing is that it doesn't really do it when it's cold...I figured it might be the slave, but it seems to be working just fine and isn't leaking. I've got a 300ZX slave I could put on there, but I don't know if that would help. Sounds like transmission needs a rebuild soon. Any thoughts? Anyone know how long these things will last if grinding if you baby them? Too bad I already sold my other motor with transmission.

[blkvrtswp]

Did you adjust the clutch pedal travel? On the pedal, loosen the set nut on the rod to the Master Cylinder, spin shaft counterclockwise 1/2 to 1 turn at a time to actuate the clutch fork a bit more. Make small adjustments - a little goes a long way. If you go too far, the clutch will begin slipping.

Good luck!