redtop sr20det swap, crank but no start

[Chris_Guthrie]

So a little background, I picked up a s13 coupe and ordered a s13 (180sx) front clip. Since I had the whole clip, I did a RHD swap, then swapped the sr in. Finally got everything buttoned up and now she won't start.

I used everything off of the front clip, everything that has a plug is plugged in, every component is where it should be, literally everything was just swapped over from clip to car.

For the wiring, I used the underdash, upper and lower engine harness from the clip (since it was cut near the seat) and the chassis harness from the USDM coupe. Just wired up the important things (fuel pump, brake/tail/signal/reverse lights, cig lighter, ashtray light, ebrake signal)... which should be irrelevant to the problem I'm having.

When I went for the first start, I noticed fuel pump was not priming. Traced that issue back to the egi fuel pump relay (relay was fine but seems to have no ground signal from the ecu). Used a jumper wire and the fuel pump works fine. I also noticed though, the egi relay (eccs relay) is also getting no signal. With the fuel pump jumped, still no start. Since the eccs relay was getting no action, I took a look at the ecu and the red light was on.

Did about a week of research, found the most common cause was a internally shorted ecu. Ordered one which came in today, hooked it up, same exact issue. Ecu was boxed very well, so it is very unlikely that it was damaged during shipping, and even if it was, the odds of it having the exact same issue are highly unlikely.

This leads me to believe that it is a wiring issue. Of course I could be wrong, but based on what I've seen so far, everyone who has had the same issue has had a bad ecu. So at this point, I am looking for advice on where to go from here.

Everything is hooked up exactly how it was on the clip, which was checked and in good operating order when I bought it. I didn't have to do the wiring mods that are required for a motorset since I had everything including the factory boost controller and fuel pump resistor that came with the clip so now I want to make sure that I'm not perhaps overlooking something simple or whatever the case may be.

Sn: all work was done by myself, in my yard, with no garage and using just regular hand tools for the most part. I do have a multimeter and am no stranger to wiring, however I am not the best at diagnosing ecus. Always went by the general rule of no fuel, no spark, replace ecu. Also, I haven't checked the plugs for fire since right now my main concern is getting a ground signal to those two relays. Any real help is really appreciated, and any bashing about the rhd swap is not needed as I just threw that in there in case it may be relevant to the issue.

[frankies1390]

i think its wiring related especially if you used everything with the front clip, youve checked your grounds? probably the #1 overlooked things when swapping a motor in, ppl get real excited and forget the one from the back of the head to firewall (exhaust side) and the 2 on the intake manifold side that bolt next to injector #4

[Chris_Guthrie]

I've actually when doing the wiring, used a wire wheel and removed all the paint/ grime from every ground. The only questionable one is the 2 on the intake by #4 injector, which I had to put on one bolt on the intake because first bolt snapped off in the hole. I'm almost certain that it's a good ground source but I will double check and post the result. The one behind the head on the exhaust side is grounded with the factory strap in the factory location. I've also verified the 2 ground on opposite ends of the crash bar are sufficiently grounded in their respective locations, the one under the left hand seat, and in the back behind the rear back/ lumbar part of the seat and in the trunk by the trunk latch are on bare metal. Also, the one on the battery tray and front intake are solid as well.

[Chris_Guthrie]

Checked the grounds today, both the ground strap on the back of the head and the 2 grounds on the back of the intake are solid grounds. The battery cable ground has a solid ground on the battery tray and the front of the intake. While I was looking at it I decided to go ahead and check the fusible links in the main fuse box by the battery. All the fusible links were good. Figured I'd go ahead and check continuity between the prongs the links plug into while I had them out. The 2 fl25a (ret mtr and eng cont) and the fl30a (ign sw) were all open. Not sure if that's relevant or its supposed to be like that since the links were out but I figured I'd go ahead and post it anyway.

Any other ideas on where to go from here? Since the grounds are solid I'm guessing that leaves me back to troubleshooting the ecu.

Another thing, I can hear the ign coil relay click when the ign fusible link is put in or if I pull it out and put it in with the key on. The egi relay is still not getting any clicking action and the neither is the egi pump relay.

I just feel like it's got to be something stupid simple causing this especially since half of the guys with the same issue either had bad ecus or missing/ bad grounds.

[Chris_Guthrie]

Bump. Girlfriend left for AIT today, so I'm looking to really put my head down and get this puppy running.

Also, anyone in the central va area with a running sr that could swing by and wouldn't mind letting me try their ecu to see if that's the problem, or vice versa, I would really appreciate it. I'm at the point now where I'm almost certain it's a bad ecu, but I need one that I know is good to try before ordering another new one. Already have 2 that may be bad, and would just like to verify before I spend the extra cash on something if I don't need it. Crashed my daily on xmas eve and looking for another daily now so every penny counts... and if I can get this running soon, that'd help out tremendously.

[Rusker]

Any updates on this?

[Chris_Guthrie]

No, still trying to find someone with a good ecu that I can try before I buy another one.

[Chris_Guthrie]

Bump. Finally got back to checking on this today. Been sitting for a while so I decided to go back and check everything out again. All grounds are solid grounds. I checked all the fuses inside the car with the key on, only one that was not getting bat voltage was #9 (.02-.03v). EDIT: Going through my diagrams when I swapped everything, #9 is E.C.C.S control unit. If anyone could tell me what that does and what it should read with the key on eng off, or if theres something wrong there and what I should do to check it i would greatly appreciate it. Again 92' US body coupe w/ red top sr20det and RHD. Entire harness is factory rhd except everything behind drivers seat which I had to run the wiring back where the half cut clip was chopped in half.

Under the hood, I checked the wires under all the relays/fuses to see what kind of voltage I was getting with the key on.
ign coil 30A, 1 (12v) 2 (12v) 3 (0v) 4 (2v) and relay was pretty warm/hot.
Egi relay, 1 (0v) 2 (12v) 3 (12v) 4 (12v),
egi pump 1 (12v) 2 (12v) 3 (0v) 4 (0v),
h/L ret cont 1 (0v) 2 (0v) 3 (12v) 4(12v) 6 (0v) 7(12v)
75a alt 12v, 12v
Blank
Fl30a p wind 12v,0v
Fl30a ret mtr 12v,0v
Fl25a eng cont 12v,3-4v
Fl30a ign sw 16v,0v
Fuses
Eng cont (-.5v),12v
Fuel pump 0v,12v
Shift lock 0v,12v
Fr fog 0v,12v
Horn 0v,12v

Turn the key on, no power to fuel pump, jump fuel pump at the relay, no ignition. Things I've been considering as possible issues -ecu (already replaced, same problem), crank sensor (haven't messed with yet), turbo timer (removed today same issue)

[Sileighty_85]

Check to if your ECU is throwing code.

You need to find out what you are not getting for combustion IE Fuel(Injectors Firing) or Spark. If you can isolate that then that will narrow your search down.

[boostin_jim]

Im having the same issue ever figure it out?