I have a 93 240sx with an sr20det swap. The car has a front mount and a top mount turbo upgrade. When driveing if you give the car more than half throttle it backfires and misses. If you keep it under half throttle you can drive the car all the way up to redline and it does fine. If you are not driveing you can stomp on the pedal and it will go to redline just fine. What do I do?? I don't know what to check anymore. I have built a boost leak tester and tested for leaks. There are none. The vent to atmosphere bov can not be the problem because under load I am not relieving and pressure. The maf is connected properly ( I am goign to purchase a new harness though just to be safe). I switched back to the old plugs they are gapped a t .028 PLEASE any other ideas or anyone inthe local area want to take a peak.

 

sounds like a few things leading from a broken intake hose, to buggered coil packs, to **** fuel.

Also could just be that it's an SR20. joking.

Try a few things like using octane booster, pull all your intake pipes off and put them all back on. Also see if one of your mates have the same ECU, and see if they'll lend it to you..

Also download the FSM, and see if you can pull codes from your ECU.. try www.nicoclub.com

Pete

 

buy a evo ? (Problem resolved).

 

u can check out www.freshalloys.com or other 240sx forums....they might have a better idea.

good luck mate.

 

I have an evo. It is my second one. Thanks for the idea though

 

seems like you're boosting okay, have you check your timing? make sure it's at the 2nd bar from the right.
It also sounds like you're misfiring, I would suggest to change to NEW factory standard plugs and DO NOT gap them.

Running rich? are you tuning with any type of software, piggyback, SAFC?

 

timing and fuel most likely fuel, my friend dan had a similar problem when he first got his done

 

how mch boost you running? you may want to try to tighten up the gap on your plugs.

 

That is one of the problems It will only boost to 4 or 5 lbs. That is the tightest recommended gap on the plugs

 

Sounds to me like your dumping too much fuel when you floor it. Check timing and you might need a FPR.