i have just fitted a new engine into my zed that has tomi race pistons etc, i was having trouble with it flooding with 555 injectors in as it hadnt been mapped, i refitted standard injectors and it started fine but it idles very irratically and sometimes cuts out when i rev it. I have tried changing the tps, cleaning injector and coil pack connectors (including the temp sensor) and changing the maf sensor but all of which have no effect. The only thing that makes it any better is if i pull off a small vacuum pipe on the n/s of the engine, about half way between the front and back but this causes it to idle very high but smoothly. Any help greatly appreciated as i am dying to get my baby back on the road.

Regards

Steve:cool:

hey bud ive moved this to 300zx help and advice, you will get more replies here

 

hope ya dont mind

nice one sorry about not putting it in the right place to start with,

cheers

Steve :cool:

not much help but having read this again (whilst soba) it sounds like you have a bost leak, ask about and see if anyone near you has a bost leak detector

i had a very similar problem a couple of years ago turned out to be the MAF although it seemed to be workin it was causing the ECU to overfuel the car, not sure if you'l need to reset the ECU before restartin the car once youve swapped.

cheers for that guys, i have tried a new ecu which didn't cure it. carried out the flash fault test last night and it flagged up det sensor fault, did some oinvestigation and found knock sensor wire snapped so im going to fix that and see if it cures it

Cheers

Steve :cool:

right, just fixed det sensor and it still hasn't fixed the problem, it seems to be hammering fuel vapour smoke out of the o/s exhaust too. could theese symptoms result from a leaking injector?

cheers

Steve :cool:

right, just fixed det sensor and it still hasn't fixed the problem, it seems to be hammering fuel vapour smoke out of the o/s exhaust too. could theese symptoms result from a leaking injector?

cheers

Steve :cool:

 

firstly when you fitted 555s did you fit the ecu with the correct map/chip, well if you have fitted 555s then you should of swapped the ecu over, if you have put it back to standard 370c injectors have you also swapped the ecu back?

 

if its flooding/ or strong fuel smell from exhaust its possible the o-ring to one of the injectors is pinched :wack: they are a nightmare TBH if its leaking bad smell around each injector find the one that leaking and remove and check for o ring damage, in most case you can see the leak and if its a rear one, it may leak down the back of the engine.

 

failing that check your injector connectors, could be a poor contact to the cylinder, is the car missing on a cylinder?

the car now has standard injectors and ecu fitted. the car isn't missfiring at idle only a little on pick up. when i changed the injectors back to standard i made sure that the o rings were seated correctly and undamaged. the injectors i refitted had a few of the plastic caps missing so i swapped them from some other ones , is this ok? help greatly appreciated

cheers

Steve:cool:

oh yea, forgot this, the car runs like it should normally do when you first start it from cold at about 1200rpm then as soon as it gets a little warmer and the revs die down a bit it starts idling all over the shop, fluctuating between 500-2000rpm. any help would be great as this is starting to get to the point where i throw the towel in and break it :shock:

 

cheers

Steve :cool:

:dance: think ive cracked it, i took off every plug on the engine loom cleaned them and made sure they were making good contact, now it seems ok

cheers for all the help

Steve :cool: