Kara Lynn Davis

ok got a 83 280zxt with a 88 z31 ecu and maf setup.ecu # is a18a02m86.just got some 380cc fuel injectors from a 70s benze.it has stock fuel pump the car is running like crap turn a corner and dies the idle is all funny.


any ideas.

NismoPick

Welcome to ZDriver!

What tune are you running in the ECU? NisTune? JWT?

FricFrac

It's an '89 NA manual California ECU.

Welcome to the forum

Kara Lynn Davis

no tune just stock ran fine with the 259cc injectors.

NismoPick

Welp... that's your problem. You can't just slap on bigger injectors and think it will run right.

Ryan Turner

bigger fuel pump Walbro 255lph Fuel pump and afpr.

NismoPick

Those things won't fix the problem...

The problem is that the stock ecu cannot compensate for larger injectors. You can't just dump in more fuel and have the a/f ratio stay the same.

Ryan Turner

so she needs to get the ecu tuned?whats the biggest injectors she can run with out getting it tuned 89 z31 na ecu?

NismoPick

^^^ I assume you are a helping friend of Kara?

The stock n/a injectors are 180cc. I'm surprised it ran fine with turbo 259cc injectors as that's a 44% increase in fuel delivery. 380cc injectors would be over 100% increase (more than double the fuel the ecu is programmed to control).

I'm not sure what she's trying to accomplish... If it ran fine on 259cc's, why jump to 380cc's?

The proper thing to do would be to run NisTune... it's fairly cheap and painless, and fully tunable.

Ryan Turner

thanks for your help its fluded now.to much fuel.has spark.

Ryan Turner

83 280zxt does not start now after i put back the 259cc injectors back in.now what.

NismoPick

It's probably still flooded... Disconnect the fuel pump connector (Green / Black wire T plug under the hatch mat) and crank the motor with the gas pedal pushed to full throttle. Do that for about 10 seconds, reconnect the fuel pump connector, and try to start it.

Also, pull the oil dipstick and smell it for gasoline. Those 380cc injectors probably contaminated the oil too.

FricFrac

It's a ZXT so the stock injectors are the 259cc injectors - I think you missed that little detail NismoPick

Ryan the stock ECU is not reprogramable - you can't just put in bigger injectors. The Z31 ECU you have can be upgraded to Nistune but the cost is close to what a real stand alone ECU like Mega Squirt would be. What are the plans for the car? That's really what will determine what mods you do to it.

NismoPick

^^^


280ZXT running an n/a Z31 ecu (n/a Z31's still run 180cc injectors). Right? I'm all sorts of confused about what's going on with this car...

FricFrac

Yea what a mess