Ok so I am working to get the new engine running (diypnp) good at idle and I have tried new coils, injectors and firmware but it still is running on 2 cyl
So when I pull the coil on #4 the back most cyl nothing changes. When I pull #2 nothing changes. pull 1 or 3 and it dies.
I have listened to the injectors and they are firing. I have spark all 4 coils tested with light and extra plug.
Its the stock wiring for the injectors and changing to fab9 cop didn't help.
Sure seems like I am running on more cyl than 2 when driving.

Some times pulling the wire of # 2 seems to effect it but it really runs about the same at idle with 2 and 4 pulled as it does with the wires hooked up.
Same with pulling #4 injector plug.

Bought engine having seen it run and with compression test.

I am out of ideas.

 

Your issue is with the injectors. #2 and #4 are batch fired in 90-93 non-CA cars. Figure out why the injectors aren't firing and your problem is solved.

 

That interesting.
Wonder why I thought 1&4 and 2&3 like in the ignition.

Well on a side note it's something to do the vvt tuner. If I take it out of the loop the thing Req alot more fuel but it idle without missing and pulling 2 or 4 effects the idle. Plus afr are some what steady with in 1 point.

Will work on it tomorrow.

Sav man thanks that will give me some place to look.

 

What could cause the interference.
It only works to unplug vvt box completely. Unplugging at vvt valve doesn't stop the problem but does change idle.

Any ideas

 

output test mode.

 

Output test mode?
I will have to search that.
3 wires are shared between vvt tuner and diypnp
Signal
Positive
Negative

Ground issue?

I know there was a lot in the vvtunner instructions about grounds but that was 3 yrs ago. I will have to read thru again.
I also noticed the diypnp install instructions have been update with a post about 5v and a resistor.

I will contact them for more direction.

Thanks for yalls help.