Supraman Posted June 9, 2005 Author Share Posted June 9, 2005 Been adjusting the HKS AFR chip with the help of Halo from Skyline Owner forum (Chris think you know him) to see if that made a difference which it didn't. Cut seems to happen around the 5K band in all gears under hard acceleration. It feels like the a stutter in the power. If I ease off the accelerator car is fine. I would like to disconnect the stock boost soleniod and then reset the ECU, but not too sure what one it is. Does someone have a pic showing were it is (stock soleniod)? I'm also not too sure what the info on the EVC display is telling me...can guess at some but measurements are in kPa. How does this translate to BAR if at all? The kPa seems set to 130 max. The reading has peaked at 117. Is anyone familiar with the units display and know how to change it to BAR? Would have inserted image but don't know how to unfortunately. Last thing I had the garage install iridium plugs. They did say that some of the coils snapped but they had managed to attach the wires. Hope this provides some clues as to what might be happening. Regardless all your help and guidance is much appreciated. Link to comment Share on other sites More sharing options...
Markie Posted June 9, 2005 Share Posted June 9, 2005 Dont have rev limiter on it do you? Link to comment Share on other sites More sharing options...
Supraman Posted June 9, 2005 Author Share Posted June 9, 2005 I didn't get English instructions with it so I don't know what the buttons or reading is telling me. Link to comment Share on other sites More sharing options...
Markie Posted June 9, 2005 Share Posted June 9, 2005 Sorry, meant on the car anywhere? Is there a rev limiter fitted? Odd it cuts at 5000RPM every gear. Could you put it in a low gear going slowly and plant your foot.. That would make it hit high boost before it gets to 5000RPM I would of thought.. Maybe someone could clarify that? Link to comment Share on other sites More sharing options...
Supraman Posted June 9, 2005 Author Share Posted June 9, 2005 Markie there is no limiter fitted. Will try the low gear test. Cheers. Link to comment Share on other sites More sharing options...
Ian C Posted June 10, 2005 Share Posted June 10, 2005 So are you saying you get a misfire at around 1 bar of boost at around 5000rpm? But if you ease off the accelerator you can smoothly pass 5000rpm? -Ian Link to comment Share on other sites More sharing options...
Supraman Posted June 10, 2005 Author Share Posted June 10, 2005 Ian C, that's about the size of it, but I wouldn't call it a misfire as such it feels more like I've a cut in power. Link to comment Share on other sites More sharing options...
Ian C Posted June 10, 2005 Share Posted June 10, 2005 Well, there are a few ways to lose power: 1. Fuel cut. A light will light up on the dash and you will lose all powers of acceleration for a couple of seconds. This usually occurs at full boost so you tend to get thrown forwards in your seat and it's very harsh. The stock level of fuel cut is anything 1 bar or above, and the higher the boost the faster cut will occur. 2. Ignition problems. 2a - weak coil packs on a single turbo - This will cause a misfire that is harsh enough to jerk you forwards and backwards in the seat as power comes on and off. Happens on boost, mostly around torque peak but pretty much anywhere in the rev range, and gets worse rapidly as the coil pack breaks down further to the point of misfiring at even 0.1bar. 2b - Spark plug gap not small enough - usually occurs on a BPU car with stock plugs, this causes a more gentle misfire where you feel acceleration fade and reappear at high boost. 2c - Too low ignition voltage - Usually occurs with an incorrect jumper setting on an aftermarket ECU/ignition system This causes a 2a-like misfire but at a repeatable boost level, below that boost level it never misfires. 3 - Overfuelling. 3a - mild overfuelling - You will get a drop in power. The acceleration will fall off and recover once you leave the rich spot. It kind of feels like you've hit a very strong headwind. 3b - heavy overfuelling - you will get stumbling like 2b as the mixture fails to ignite. This will clear up as soon as you leave the rich load site on the map. 3c - massive overfuelling - you will get a drop in power harsher than 3b but less harsh than 2a. The engine pretty much won't get past the load site, it will just keep cutting out, so acceleration is lost. 4 - Air leak. 4a - Some or all power suddenly drops off due to a popped off hose, and the power is gone until the hose is replaced 4b - Some or all power intermittenly fades because a split hose opens up and vents boost pressure 4c - There is a problem with your sequential turbo system Pick one of those -Ian Link to comment Share on other sites More sharing options...
Clarkey Posted June 10, 2005 Share Posted June 10, 2005 Great post Ian Link to comment Share on other sites More sharing options...
Supraman Posted June 10, 2005 Author Share Posted June 10, 2005 Ian C, I am inclined to go with 2a or 2b. I would think 2b because the plugs were replaced before the other work was carried out and the symptom are in line with what I'm experiencing. Any idea what gap the plugs should be set to for 1.2 BAR? I have discounted 2a because adjusting the AFR to vary air/fuel mixture has no effect on the problem although I really need to get someone to set this up correctly for me. I also think that I need to remove the stock soleniod and reset the ECU which I hope to do later today. Thanks for taking the time to put such an exhaustive list together and would say this is definately one for the club FAQ area. Once again thanks to all and if any of you that have helped on this thread are at this Sunday's Lake District meet I'll buy you a soft drink (because we'll all be driving). I had been quoted a lot of dosh to diagnose this fault so if anyone was swithering on whether to renew their club membership this thread (and many more no doubt) should make the answer a no-brainer! Link to comment Share on other sites More sharing options...
Ian C Posted June 10, 2005 Share Posted June 10, 2005 The gap should be 0.8mm for BPU, a spark plug expert should be along shortly to tell you what is a good plug for that level of boost as well (you'll need a grade colder than stock) I'll wait for people to poke holes in my post before promoting it to FAQ level, glad you found it helpful -Ian Link to comment Share on other sites More sharing options...
Alex Posted June 10, 2005 Share Posted June 10, 2005 0.7mm to 0.8mm should suffice on plugs such as BCPR7ES's and BKR7E's from NGK. Failing this get NGK Iridium BKR7EIX's or Denso IK24's both of which come pregapped. Link to comment Share on other sites More sharing options...
Supraman Posted June 10, 2005 Author Share Posted June 10, 2005 Cheers Alex Link to comment Share on other sites More sharing options...
Markie Posted June 10, 2005 Share Posted June 10, 2005 I run a TT running 1.2. I have had no trouble with the Denso IK24's. Link to comment Share on other sites More sharing options...
Supraman Posted June 13, 2005 Author Share Posted June 13, 2005 Cheers Markie Link to comment Share on other sites More sharing options...
tDR Posted June 13, 2005 Share Posted June 13, 2005 Sounds too much of a coincedence not to be ignition related - coil packs or plugs IMO. Could you borrow a set of coil packs from someone elses car to eliminate that? Cheers, Brian. Link to comment Share on other sites More sharing options...
Supraman Posted June 13, 2005 Author Share Posted June 13, 2005 Sounds too much of a coincedence not to be ignition related - coil packs or plugs IMO. Could you borrow a set of coil packs from someone elses car to eliminate that? Cheers, Brian. Brian, Thanks for the suggestion. There isn't anyone close enough to me unfortunately. I'm going to go back to the guy that did the work with the suggestions from this thread and see what he can find. Rgds Neil Link to comment Share on other sites More sharing options...
Ian C Posted June 13, 2005 Share Posted June 13, 2005 I'd go for the spark plugs first, cheapest option, a set of NGKs is about £8 -Ian Link to comment Share on other sites More sharing options...
Supraman Posted June 14, 2005 Author Share Posted June 14, 2005 I'd go for the spark plugs first, cheapest option, a set of NGKs is about £8 -Ian A sensible suggestion...I know the plugs were replaced recently with iridium ones. Quick question is it an internal wastegate (signle port actuator) or an external wastegate/dual port actuator on the Supra? I have stock jap spec turbos. Link to comment Share on other sites More sharing options...
Alex Posted June 14, 2005 Share Posted June 14, 2005 internal wastegate. Link to comment Share on other sites More sharing options...
Supraman Posted June 14, 2005 Author Share Posted June 14, 2005 internal wastegate. Cheers Link to comment Share on other sites More sharing options...
tDR Posted June 14, 2005 Share Posted June 14, 2005 I'm not sure I can see how they could fcuk up fitting a set of irridium plugs considering they don't even need gapped... unless that is where they have gone wrong (trying to gap them damages the fine electrode). I can see that they could have done some permanent damage to the coil packs if they didn't remove them correctly and have now bodged them up. If you fancy contacting Hamish (Getrag) and arranging with him for you both to come to mine, I'll swap bits between your two cars 'til we find the culprit. I'm just up the road from the Brucefield meet - Hamish knows the way, I fitted his plugs for him - we have a nice kitted out large double garage here Cheers, Brian. Link to comment Share on other sites More sharing options...
Supraman Posted June 16, 2005 Author Share Posted June 16, 2005 I'm not sure I can see how they could fcuk up fitting a set of irridium plugs considering they don't even need gapped... unless that is where they have gone wrong (trying to gap them damages the fine electrode). I can see that they could have done some permanent damage to the coil packs if they didn't remove them correctly and have now bodged them up. If you fancy contacting Hamish (Getrag) and arranging with him for you both to come to mine, I'll swap bits between your two cars 'til we find the culprit. I'm just up the road from the Brucefield meet - Hamish knows the way, I fitted his plugs for him - we have a nice kitted out large double garage here Cheers, Brian. Brian, That would be great! Thanks for the offer. I'll pm Hamish. Link to comment Share on other sites More sharing options...
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