hodge Posted February 26, 2012 Share Posted February 26, 2012 Hi guys. Bit of a strange one this. We has our local jap car meet today and we had a new member turn up in his Supra. He asked me for some advice and if I'd have a look at his car as there was an issue with the idle. To cut a long story short, this poor guy had a TT conversion done at a company called Nippon. To say I was unimpressed is a total understatement. The engine earth was not connected, the battery was just rattling around with no tray or clamp, the turbo VSVs were all plummed wrong, and I can't find a pressure tank under the plenum. The car is over boosting and hitting fuel cut, speedo is 50mph out and the rev counter doesn't work. There parts bent, and broken all over the place, and they charged him a fortune for the job. Anyways, here's the problem. From cold the car starts and runs fine but once it warms up the idle goes up and down horrendously. It doesn't hunt, but goes from what I can here 1k-2k and continues to do this. I've never heard anything like it before. The revving is very smooth indeed, which tells me it isn't hunting but something is making the revs do this. As soon as i touch the throttle its smooth as hell. Could this be a faulty throttle body maybe, or an air leak on the plenum/throttle body. Any ideas guys, I feel really sorry for the guy who's had his eyes ripped out by this place for what only I can discribe and a VERY poor attempt at an engine swap. So I said id help him out and get it sorted. Thanks John Quote Link to comment Share on other sites More sharing options...
Iky Posted February 26, 2012 Share Posted February 26, 2012 The way you describe the workmanship makes me feel that the problem could be literally anything from a broken wire to a leaky boost pipe. Can he get it to C.W or any other reputable garage familiar with NA/TT conversions? I feel sorry for the chap as well. Quote Link to comment Share on other sites More sharing options...
Ian C Posted February 26, 2012 Share Posted February 26, 2012 This sounds like a big air leak on the intake. Too much air goes in with no throttling so the engine revs rocket up. The ECU detects rising revis with a closed throttle and idle control valve and cuts ignition or fuel to preserve the engine. It drops back to idle and revs up again, repeating the cycle. Either the ICV is stuck open or there is a big air leak somewhere, like a missing pipe. I hate bodge jobs like this, ruining someone's car with blatantly bad work and charging them Quote Link to comment Share on other sites More sharing options...
hodge Posted February 26, 2012 Author Share Posted February 26, 2012 He's giving me a ring next week, I'll strip the plenum off and check it all out. Whilst I was looking under the plenum I couldn't see a pressure tank present either. I'll get to the bottom of it for him I hope, then he can start enjoying his car. Quote Link to comment Share on other sites More sharing options...
hodge Posted February 26, 2012 Author Share Posted February 26, 2012 Thanks for the input guys. I'll let you know how I get on when he rings me. Quote Link to comment Share on other sites More sharing options...
CanisLupus Posted February 26, 2012 Share Posted February 26, 2012 If it's nothing with the TB and Plenum take a look at the ECU connector and all wires. My +12V on key to the ECU was faulty and it was hunting too when that happened. Quote Link to comment Share on other sites More sharing options...
hodge Posted February 26, 2012 Author Share Posted February 26, 2012 I've got a feeling it's something to do with some sort of air leak but I'll check that out if nothing presents itself. Quote Link to comment Share on other sites More sharing options...
dude Posted February 26, 2012 Share Posted February 26, 2012 Sounds terrible, whay cant he go back and complain?? How much was he charged?? Quote Link to comment Share on other sites More sharing options...
hodge Posted February 26, 2012 Author Share Posted February 26, 2012 Sounds terrible, whay cant he go back and complain?? How much was he charged?? The price was about average for the conversion, but honestly John, my son could have done a better job. It's a total joke. If it were me I'd have it all pulled back out and done again, replacing everything that's damaged, but it ain't my car. I've got a few parts lying around that I'll bung on for him and help the guy out. Quote Link to comment Share on other sites More sharing options...
dude Posted February 26, 2012 Share Posted February 26, 2012 Id be going back with a list.........................and a baseball bat !!!! Quote Link to comment Share on other sites More sharing options...
CanisLupus Posted February 27, 2012 Share Posted February 27, 2012 Id be going back with a list.........................and a baseball bat !!!! Fully agreed! Quote Link to comment Share on other sites More sharing options...
hodge Posted February 27, 2012 Author Share Posted February 27, 2012 The guy is a new member on here who owns the car, but can't remember his user name. If he calls me this week I'll take some pics and post them up if he doesn't mind just to show how bad it really has been done. Quote Link to comment Share on other sites More sharing options...
Josh Posted February 27, 2012 Share Posted February 27, 2012 The guy is a new member on here who owns the car, but can't remember his user name. If he calls me this week I'll take some pics and post them up if he doesn't mind just to show how bad it really has been done. Interested in the pics. Hopefully no one on here will ever go to the company mentioned for work. Quote Link to comment Share on other sites More sharing options...
Westy Posted February 27, 2012 Share Posted February 27, 2012 Feel for him, that's the last thing you want when you have forked out a load of your hard earned! The car will be in capable hands with you John! By the time it's finished the bay will be shiny and decluttered!:d:d Quote Link to comment Share on other sites More sharing options...
bigbloodyturbo Posted February 28, 2012 Share Posted February 28, 2012 If the chap is needing any bits or if anything has been broken when the nuggets installed it I have a load left over from my single conversion that he is welcome to if he pays postage. Got two sets of vsv's and a pressure tank aswell. Hate when people get mugged off and then expected to pay for it. Quote Link to comment Share on other sites More sharing options...
hodge Posted February 28, 2012 Author Share Posted February 28, 2012 If the chap is needing any bits or if anything has been broken when the nuggets installed it I have a load left over from my single conversion that he is welcome to if he pays postage. Got two sets of vsv's and a pressure tank aswell. Hate when people get mugged off and then expected to pay for it. Thanks bud, I'm sure Simon will appreciate that. Ill be in touch bud. Thanks very much. Quote Link to comment Share on other sites More sharing options...
hodge Posted May 11, 2012 Author Share Posted May 11, 2012 Bit of an update on this guys. WELL, I'm at a total loss if I'm honest. I've removed the plenum, TB runners and injectors. Everything has been checked and cleaned and put back together. I've replaced every vac line on and around the plenum, I've fitted another ICV, throttle body and TPS but it's still the same. If I adjust the TPS while the car is running, I can either get it to run smooth at 2K if it sits in the middle of adjustment, it revs itself between 1-2k at 1 end of adjustment and seems to struggle to idle at the other end and looks like its overfueling slightly with splutters and a little black smoke. If I unplug the ICV the car will idle at around 1200 RPM. Anyone have any ideas. Ian.C's theory seems to be on the right track as the idle levels off when the ICV is unplugged but god knows where the leak could be cos I've checked everything. Any help would be great guys Cheers John Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted May 11, 2012 Share Posted May 11, 2012 Propane wand is your friend for vac leaks. has it got the RIGHT throttle pot for the ecu fitted? have you set up the throttle pot per the shop manual? Once you fiddle with the factory set throttle stop screws you lose the original reference point, so it gets tricky. You need to scope the ecu outputs to the IACV, check it's trying to control the idle. Is the PCV valve leaking? Easiest advice is don't speak to strangers with high idling cars Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted May 11, 2012 Share Posted May 11, 2012 Have you changed the traction control butterfly motor??? Quote Link to comment Share on other sites More sharing options...
Bossco Posted May 11, 2012 Share Posted May 11, 2012 What about a broken map sensor? My car was ideling all over until you kicked my old sensor into the bushes and I put a new one on. Quote Link to comment Share on other sites More sharing options...
Colin-mkiv Posted May 11, 2012 Share Posted May 11, 2012 O2 sensor maybe? The muppets might not have fitted a wider band one in place of the NA ones Quote Link to comment Share on other sites More sharing options...
hodge Posted May 11, 2012 Author Share Posted May 11, 2012 Propane wand is your friend for vac leaks. has it got the RIGHT throttle pot for the ecu fitted? have you set up the throttle pot per the shop manual? Once you fiddle with the factory set throttle stop screws you lose the original reference point, so it gets tricky. You need to scope the ecu outputs to the IACV, check it's trying to control the idle. Is the PCV valve leaking? Easiest advice is don't speak to strangers with high idling cars Have you changed the traction control butterfly motor??? Yep the throttle position sensor is all set up correctly Chris. By PCV do you mean the pressure tank under the intake runners. I inspected it whilst I had the intake side stripped down. I couldn't see any evidence of cracking at all. It may be worth swapping out though just to iliminate it from the equation. The trac stepper motor isn't used, the car has had a TT conversion and didn't have traction control, so I didn't think it was an issue there. Oven even swapped the ECU incase there was an issue there but I guess not. When the car arrived it has a GS300 auto ECU in it and the car is a 5 speed manual so I fitted a 6 speed ECU. Quote Link to comment Share on other sites More sharing options...
hodge Posted May 11, 2012 Author Share Posted May 11, 2012 And yes I think your right Chris, I need to be a little more thoughtful about befriending people with Irratic idle issues lol. Nah seriously, Simons a good bloke. Quote Link to comment Share on other sites More sharing options...
hodge Posted May 11, 2012 Author Share Posted May 11, 2012 What about a broken map sensor? My car was ideling all over until you kicked my old sensor into the bushes and I put a new one on. Already tried it Bro O2 sensor maybe? The muppets might not have fitted a wider band one in place of the NA ones N/A and TT both have narrow band sensors Colin. An N/A has 2 and the TT only has 1. If the sensor was faulty the car would just overfuel horrendously. Quote Link to comment Share on other sites More sharing options...
Colin-mkiv Posted May 11, 2012 Share Posted May 11, 2012 Have you tried an uprated fuel pump or changed the fuel filter? (clutching at straws now like) Quote Link to comment Share on other sites More sharing options...
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