i have an 89 auto TT I replaced the oem injectors with new nismo 555's a while back and left it in the garage since. motor idled very smooth and revved well, but very rich as expected. finally got around to socketing and chipping the ECU a few weeks back with 'made to order' eeprom to suit my setup and get me on the road until i can afford a proper tune. when i put the ecu back in the car both exhuasts smoked heaps, and it ran extremely rich, idled ok but revved very roughly with more smoke. i have a spare good ECU which i put in and that one now runs the same ! both units are throwing code 55 - no errors, but i note that the diagnostics only check input circuits. wondering if i might have shorted something on the board which might have damaged something outside the ECU ? any ideas on how to diagnose my problem or where to look now ? thanks !
after putting it into gear just now i found that it idled very rough - probably only running on 3 or 4 cylinders, so tomorrow i'll look for spark and pull the cas off and turn it to hear if all the injectors are firing
thanks for the reply Rollin, both ECUs were running well with 555s before i chipped it , just rich. The eprom was mapped for 555s, auto box & my aftermarket exhausts
Sounds exactly like the issue I am having since fitting 550cc injectors to my TT. Microtech has reduced injector opening time(to account for larger injectors)but still smoking like a bitch, and undriveable by any standards. Been off the road for several weeks with no solution in sight(other than to scrap the bloody thing, and continue catching buses).
what kind of spark plugs are you running? iridiums and platinums are very easy to foul and need to be replaced after the fact..
If you're not taking your car to be tuned professionally, as a minimum install a wideband O2 sensor. Good idea to install one anyway as soon as you start changing things like injectors, air intakes, ecu's or anything to do with fuel/air.
A handpiece is actually more suitable for this. You can navigate to the screen that contains the setting you need easily while out on the road. Im not actually familiar with how M/T lay their software interface out tho. Located in the OPTIONS screens is MIXTRM This is a global fuel adjustment that works over the entire range. Im assuming your engine is running crap and black smoking across the rangedue to the larger injectors so reduce this figure by, say 5% at a time and see how it responds. Just reduce it to the point where it will keep idling drive and head very carefully straight to your nearest and dearest tuner. E
you can have a copy of my tune if you want mate im on a ltx12 aswell, its setup for 740 cc injectors, to change to 555s you would only have to modify the idle settings really do you want me to have a look at your tune .
That's a recipe for a melted piston 740's will need less injector duration than 555's for the same amount of air. Running 555's with a tune configured for 740's will run a lean mix.
managed to get a little time on it today - injectors all firing ok. - pulling the coil pack leads causes idle revs to drop on all cylinders except 4 - found it had very weak spark almost invisible, then found 2 was pretty weak also - no time to go further but I'm thinking i'll check some of the others and start looking at the earth wires on the ECU harness ( because they've been disturbed many times now ) and also the ignition relay. coil pack that's on 4 is ok so there might be an issue with the PTU or signal wire on the ECU harness connector. might be a while til I get back onto it. thanks for the help peeps - and any more suggestions welcome !
can't remember - custom ebay job from the US so you reckon twin 3"exhuast no different to single 3"or twin 2"as far as tuning for peak power goes ?
dude. really? you have put in a generic ebay chip and are still wanting to run it after it is blowing smoke? put that thing in the bin where it belongs and get toshi to make you up a proper chip or someone who has already offered on this thread to check the chip and possibly make you one that is not going to damage your motor. possibly better to do it asap rather than in 5g's worth of damage time.
You didnt mention spark plugs in there.. always try the easiest/cheapest fixes first. Something like PTU or coilpacks arent suddenly going to change after the symptoms you described. Spark plugs however, wont operate properly and will deliver weak/no spark if fouled.
No offence Wayne, but maybe you should be taking your own advice. You've been a big advocate of your own generic Tomei chip but at the end of the day it's no different, possibly even more of a risk due to being optimised for higher octane Jap fuel. Most ebay chips are JWT or Z1 copies. That said I'm running an ebay chip for 550cc injectors and report no issues whatsoever. No knock, a little bit rich but that's it. Boosting fine to 17psi on GT525s :br:
Thanks for the input Tass, however, I have already got complete Laptop access to the Microtech screens/pages to which you refer. Microtech in Sydney(Gladesville)has checked-out my ECU and made a 45%(MixTrim) reduction to the fuel delivery to accommodate the 550cc injectors now fitted(as opposed to the 380cc items previously installed). This has NOT fixed the problem. It should also be noted that this car is NOT blowing clouds of Black/Grey smoke as would be expected from serious "Over-fueling"(the "smoke" is White, does not smell of unburnt fuel and dissipates almost as though it was Steam(which it plainly is not). All Spark-plugs AND Coil Packs have been replaced with brand new items. This has me stuffed!
