So I just recently finished T2 swapping my 86 GX, everything was running fine and dandy until recently.

Here's the story:
I figured that my NA exhaust was too restrictive for the T2 swap (the Y pipe for dual exhaust was tiny ~1 inch) so I drove the car to my fabricator's shop to have a full exhaust system made. I went to pick up the car yesterday and it's running on one rotor, spent some time trying to trouble shoot and couldn't get it running properly

???

Some notable things about the swap:
- Walbro 255 installed
- Fuel pump rewire performed
- FPD removed
- Timing/idle speed/idle mixture has not been set yet
- All vacuum lines have been replaced
- Sub zero blocked off
- Split air blocked off (previous owner)
- TB mod performed (previous owner)
- ATF trick performed (previous owner)

The first thing I tried was to completely deflood the engine by cranking the engine with the spark plugs out and replacing the spark plugs with fresh ones thinking that the short run time moving the car from the parking lot into the shop had somehow flooded one rotor. No improvement. Compression pulses sounded strong and even. Compression test I performed prior to swapping the engine in showed 105psi.

I've confirmed spark on the trailing coil. It seemed as though the rear rotor is the one that is working properly when I did this, the engine ran for a split second when I was checking the front trailing wire for spark where as the engine just kept cranking when I was checking rear trailing wire for spark.

Any help would be appreciated, I need to get that car out of the shop, they're already accommodating me by letting the car stay there until I figure it out or tow it out. Cheers guys!

Here's a picture for your time.

 

Assuming a mechanically healthy engine with good compression:

Your engine will start and run on leading plugs (the lower ones) just fine. I have tried it. The trailing (top ones) are just for added efficiency.

Verify your ignition cables. Sometimes the contacts dont grip very well on the plugs or coils, or they are internally broken. You can check the resistance with an ohmmeter. Ignition cables are subject to wear. Verify that you have spark on at least both the leading plugs.

If your motor is flooded you will notice wet plugs, deflood it again and spray some WD40 in there to lube the chambers and get some extra compression. Then try to start again.

If you have compression, spark and your motor is still not starting or just running on one rotor then its likely a fuel issue, stuck or clogged injector. Even with one flooded rotor your engine should be able to start and get both rotors working just a couple of seconds after startup if you keep the revs up with the gas pedal. I have done that hundreds of times. If the second rotor doesnt run at all then it has either no spark or fuel.

 

DING DING DING!

Rear primary injector somehow died at the right time and the right place to perfectly mess with me!

Moved one of the secondaries to the primary position and babied ( > 3800rpm ) the car home! Glad I got the car out of my fabricators shop. Car was hunting for idle though, I must have left a vacuum source off or something in the rush to get it out. Gotta fix that, replace the injectors, replace the clutch and I'll finally be happy with it.

Thanks a ton for your help!

 

i was gonna say, they probably took it for a spin...

 

While I understand that this could happen anywhere, I had full faith that this wasn't the case. I do have to say though, that my brother and I have dealt with Centerline Motorsports for what is about to be the last decade and we have never once questioned their professionalism or even had the slightest concern that our cars were in any danger.

It's all good though! We figured it out, no one was at fault (except for the car, hehe) and the culprit was found!