SR swap running issue-you'll have to be pretty smart for this one.....

[Spdrules5]

Blacktop SR20DET with 5spd into 89 coupe (auto to man conversion done).
Car will barely start, then runs on two cylinders(the middle two only). I unplug the MAF and it makes no difference, BUT, the RPM's WILL raise over 2500 rpm no problem.

I have:
- replaced MAF with known good one--no change
- replaced ECU with known good one--no change
- replaced CAS with known good one--no change
- chkd' continuity between sensor plugs and blue ECU plug--all seem good
- replaced wire harness with known good one--NO change!
- pulled valve cover and put CAS 180* off--would not start

I have pulled each coil pack one at a time and checked:
-spark across gap--all fire
-constant 12v to top of coils--all good
-ground--all good
-signal--something measured as it fired
-all gapped at 0.032

All grounds are attached in approprite places

I am at a total loss. Please help.

Thanks in advance

[Nissandriver714]

1. Do a compression test.
2. Check injectors

[Spdrules5]

Needed to add more info:
Injectors were just rebuilt by RC engineering and I have all new o rings and seals.

How do I check injectors? Pulling them out of the fuel rail destroys the o rings. Just pull the whole fuel rail and crank the motor over to see fuel sprays from all injectors?

[the head]

that will work for the rail just pull and watch for the spray get some compression numbers you may have a blown engine

[Spdrules5]

I'll try both.

[timmybgood]

what about the ignitor? if you said its running on only 2 cyls that could be it.

to check if an injector is running, put a screwdriver against the injector then put your ear upto the handle and listen. if its working you'll definatly hear it

[sactos13]

Mixing up harnesses or cpu's between red and black top's will cause it to run on 2 cylinders as well. I'd check the number on the cpu and match it up with what's in the FAQ

[Spdrules5]

I replaced the wire harness with a '98 blacktop wire harness with ignitor from a friends '89 coupe with blacktop that runs perfect. Still the same thing, runs on two cylinders.
i pull each coil pack with spark plug and turn the motor over and it throws spark across the gap on the two cylinders that aren't running.
When the engine is runing, I pull the plug to each coil pack individually, and only the 2 inside cylinders make a difference. I unplug the MAF and it makes no difference in idle, BUT, I can rev way past 2500 rpm's.

That is why this is killing me. It makes no sense. Coils and plugs are all getting power, signal, and spark when checked individually, but put it all together and it only runs on two cylinders.

I'll try the screwdriver on the injectors today.
Thanks for the thoughts, please keep them coming.

[Id-]

well if you're getting spark on those cylinders, then its obviously fuel, it couldnt be anything else other than that; unless you've got popped cylinders

[Spdrules5]

New update:

I pulled the fuel inj. out one by one and re-installed them. I know have 3 cylinders working. One of the fuel inj. aren't clicking open/close. I moved it to another cylinder, then that cylinder didn't work but the first one did.
Fuel injectors were just serviced by RC Engineering. They flowed all the inj. and gave spray rates and such on paper. I'll take the one back and see if they will do something.

**I can still unplug my MAF and it won't affect driveability. One problem at a time I guess.

[F3600]

Look for error code in the ecu... when a problem arise, its the first thing to do...

[Spdrules5]

Look for error code in the ecu... when a problem arise, its the first thing to do...

I'd love to, but I used the search on how to do it, and my ecu doesn't do it.
I turned the key off,then turned the little tuning pot thing in the right direction, turned key to the on position, but the light just stayed on. Tried many different things.
How do I do it?
Also, if a blacktop ecu doesn't have an led in the ecu, how do you do it?

Thanks

[Id-]

did you check the impedance for the malfunctioning injectors? just something to look at while you're waiting on RC

[Spdrules5]

The injector pintle was stuck closed. They had to re-service the injector. It took 2 hours. I'll be installing as soon as I'm done with work.

**The MAF still doesn't need to be plugged in in order to rev the motor to any RPM.
Any thoughts???

[silviasichigo]

Could have popped off a intercooler hose or maybe the BOV is stuck open, or something, it will run like ass and still run over 25k with the maf off check your hoses and pipes.