Problem After Gtr Injector Install

[ashr32]

Hi Guys,

ok this is a tough one. ive put my GTR injectors into my r32 rb20det. i used a resistor pack and wired it in. i have attached a drawing to show you how i did it.

so i checked everything and put it all back together, turned the key and no fire. that was with the stock ecu. i thought it wouldn't anyway but it was worth a shot. anyway i connected the (power FC) and it started first try perfect!!!!!!

runs great until it starts to warm up then it gets a massive mis and the revs rise and fall in a patten. it sounds like a washing machine.

this issue wasnt there before the changover

ive played with all the wires and plugs for both the injectors and coils.

the injectors are firing cuz i can hear them tick and when i take the coils of 1 at a time i can see the sparking

when i remove a plug, injector or coil the mis becomes constant but the problem is still there

i had the car booked in for a pfc tune saterday so i drive the car 20kms to get there. it drive fine under 3k with little to 0 knock. so i get there with the hope it the tune would fix it but no go. they tried new plugs and an ignighter and tried to dyno it to get some data but as soon a it got on boost the mis was a constant droped cylinder. sounded aweful.

the tuner said that he increased a % on number 2 injector to 80% and its helped it a bit but still a problem. he said it could be a blocked injector and to get it retested. they were tested and cleaned 2 days earlier but this could be the problem as it was hard to get the rail and new injectors into position with the top intake still on and not letting the injector touch anything else.

so guys any ideas?

i need the car for a daily all week and the tuner said i could bring it in tomorrow but if i cant fix the mis it cant be tuned. the tuner has been good to me and i know they are busy so i dont want to have them spend another 4 hours trying to find a problem before the tune.

please guys im stuck

[The Dan]

As I understand it, the POWERFC triggers the injectors in a different way or has a different way of reducing resistance or increasing it. I'm not 100% sure of the exact issue but I've fixed them before by putting injectors in that actually suit the car.

Putting standard GTR injectors back into a GTR is a shit of an idea to start with, let alone putting them into an RB20 with resistors. They are almost guaranteed to leak and with the cost of install of resistors, install of injectors, and then the cost of the injectors themselves you could have had a set of SARD 550's for about $100-$200 more and it would be running sweet right now.

[ashr32]

As I understand it, the POWERFC triggers the injectors in a different way or has a different way of reducing resistance or increasing it. I'm not 100% sure of the exact issue but I've fixed them before by putting injectors in that actually suit the car.

Putting standard GTR injectors back into a GTR is a shit of an idea to start with, let alone putting them into an RB20 with resistors. They are almost guaranteed to leak and with the cost of install of resistors, install of injectors, and then the cost of the injectors themselves you could have had a set of SARD 550's for about $100-$200 more and it would be running sweet right now.

this upgrade has been done successfully a number of times by members of this forum. there is even a guide on doing it. i don't need 550cc injectors and i did all the work myself. with the current exchange rate this is a more viable option IMHO. flow testing and cleaning rules out leaking and the injectors are from a r33gtr with 35k on the clock NEW ENOUGH

you have offered me info you are not sure on and an opinion that is useless to my current situation.

well done...

[SATO GTS]

Try going back to std injectors and making sure that the problem does not exist while in std trim.

If it does then you know there is a issue there somewhere, if not then it is something that you have done to upset the engine.

You havn't put the earth wire's onto the wrong inj's causing them to fire in the wrong sequence?

You made sure your getting 12 volts at the inj's

P.S no pic shown

[The Dan]

this upgrade has been done successfully a number of times by members of this forum. there is even a guide on doing it. i don't need 550cc injectors and i did all the work myself. with the current exchange rate this is a more viable option IMHO. flow testing and cleaning rules out leaking and the injectors are from a r33gtr with 35k on the clock NEW ENOUGH

you have offered me info you are not sure on and an opinion that is useless to my current situation.

well done...

The comments I made did not call for a nasty comment in reply.

I have fixed enough of these so called 'successful upgrades' to know otherwise. I have tried to understand why the problem occurs but, unfortunately, it's not as simple as just asking the guy down the street for answers. I did not build the powerfc, nor did program the software, so I cannot shed you any light on the subject conclusively. I have, however, given you information that I and another reputable mechanic have come across while researching the cause of the problem.

If you want to be pig headed about it, then go right ahead. I'm just trying to give you the information it has taken months to come across.

GTR injectors on 32, 33 or 34. I've replaced them all at one stage or another for leaks. Don't think for a second that they are a reliable option.

If you want the budget option then accept the budget idle.

I know many people have done this changeover without problems but it would seem Apexi have changed they way they make their units from the ones that work to the ones that don't. It may be a simple fix, which I hope it is for you, but unless you are willing to take advice from people who spend their lives doing this sort of thing, then you are not going to get anywhere.