k31th less WHY; more WOT Site Developer 29,071 Member For: 16y 8m 19d Gender: Male Location: Melbourne Posted 12/09/24 08:15 AM Share Posted 12/09/24 08:15 AM that's an interesting situation... great at WOT but nowhere else along the stuff... well, good work on sorting it Link to comment Share on other sites More sharing options...
Puffwagon Puff Gold Donating Members 15,998 Member For: 9y 11m Gender: Male Location: South Australia Posted 12/09/24 08:30 AM Author Share Posted 12/09/24 08:30 AM Yep at 50% throttle getting up to 100kph, it uses 99.9 on the dash, then if you floor it, it drops to 80 something before going back up when the boost kicks in. Hopefully I can get it sorted cos I've used half a tank to do 110km so far, a sh*tty situation to say the least. I really gotta say again, the mofo moves out when the appointment for boost arrives lol. Test drive today showed 27 to 28psi, still with only 5 degrees of timing, feels like high 400s, if not a tiny bit more. The dyno can wait until I fix the fuel problem so will be a week or two, smoke machine arrives next week so updates will happen then. 1 Link to comment Share on other sites More sharing options...
bjc Donating Members 2,823 Member For: 21y 3m 26d Gender: Male Location: Townsville Posted 12/09/24 09:44 AM Share Posted 12/09/24 09:44 AM The Haltech isn't stuck on wot afr for your cruising? I assume it runs a wideband and has CL fuel control. All injectors are firing together for that old school carby style smell lol Link to comment Share on other sites More sharing options...
Puffwagon Puff Gold Donating Members 15,998 Member For: 9y 11m Gender: Male Location: South Australia Posted 12/09/24 10:44 AM Author Share Posted 12/09/24 10:44 AM Haha no if it was that simple I would have picked it up immediately It was literally fine one day and farked the next, with nothing untoward happening to indicate an issue. I've ruled out a lot of things so far, CBF listing it all now but it's extensive. I have two wideband units, one for the haltech for closed loop fuel control and a seperate unit for a gauge. Both read the same and the plugs aren't getting fouled. It also runs sequential injection, so there is no batch firing going on. It's using the fuel but it isn't running rich according to the plugs. I'm going to check for leaks on the hot side with the smoke tester, then look into the converter possibly being farked. I've already visually checked the manifold for cracks when it was off, I could have missed something. I replaced the vband at the top of the dump pipe today, the previous one was just flat faces together, the new one is designed for the turbine housing outlet and locks into place. There ain't no leaks from that sumbitch. The wideband sensors are immediately after that, so there is either a leak in the manifold or something else is happening. Long story short, the fuel is getting used and the plugs are reading normal, therefore the engine is getting dragged down by something. 1 Link to comment Share on other sites More sharing options...
xr6tForMe Donating Members 268 Member For: 11y 6m Gender: Male Posted 12/09/24 11:30 PM Share Posted 12/09/24 11:30 PM Not sure if any of this might help, but here goes: Are the widebands reading that AFR is ok, or would widebands be seeing rich/lean and adjusting the fueling to compensate? If there is a boost leak, does the map sensor not still see the actual boost, and the tune is still ok? eg turbo is pushing enough air to make to make 25psi, but 5 leaks out, so there is still 20psi and map sensor reports 20psi and tune is ok? Would a converter problem explain "at 50% throttle getting up to 100kph, it uses 99.9 on the dash, then if you floor it, it drops to 80 something before going back up when the boost kicks in" ? Can you log boost and injector duty cycle when it is doing "at 50% throttle getting up to 100kph, it uses 99.9 on the dash, then if you floor it, it drops to 80 something before going back up when the boost kicks in" to see that they make sense together? Link to comment Share on other sites More sharing options...
Puffwagon Puff Gold Donating Members 15,998 Member For: 9y 11m Gender: Male Location: South Australia Posted 13/09/24 12:02 AM Author Share Posted 13/09/24 12:02 AM 15 minutes ago, xr6tForMe said: Are the widebands reading that AFR is ok, or would widebands be seeing rich/lean and adjusting the fueling to compensate? The widebands read exactly as expected. If there was a an air leak introducing air into the exhaust, the sensors would compensate and add extra fuel. They would read normal but in that case the extra fuel would show up on the spark plugs. The plugs look perfect. 17 minutes ago, xr6tForMe said: If there is a boost leak, does the map sensor not still see the actual boost, and the tune is still ok? eg turbo is pushing enough air to make to make 25psi, but 5 leaks out, so there is still 20psi and map sensor reports 20psi and tune is ok? The fuelling is primarily dictated by the map sensor in the plenum and rpm. If there was a leak in the plenum, the car would still just measure the boost in there and give it the amount fuel it was tuned for at that boost level. 19 minutes ago, xr6tForMe said: Would a converter problem explain "at 50% throttle getting up to 100kph, it uses 99.9 on the dash, then if you floor it, it drops to 80 something before going back up when the boost kicks in" ? It's the only thing doing something between the engine and the transmission at idle, it's spinning the trans pump and slipping internally while the input shaft stays still. I'm no converter or transmission expert though but I do have a spare to install to see if it changes anything. 22 minutes ago, xr6tForMe said: Can you log boost and injector duty cycle when it is doing "at 50% throttle getting up to 100kph, it uses 99.9 on the dash, then if you floor it, it drops to 80 something before going back up when the boost kicks in" to see that they make sense together? I've done this, I can also log instantaneous fuel economy and it is actually quite a bit higher than 99.9. There's a couple of checks I'll do before swapping the trans and converter. Haha I wanted a converter upgrade anyway, so I'm secretly hoping it is that. Haha not so secret now though! 1 Link to comment Share on other sites More sharing options...
Puffwagon Puff Gold Donating Members 15,998 Member For: 9y 11m Gender: Male Location: South Australia Posted 14/09/24 06:29 AM Author Share Posted 14/09/24 06:29 AM Ended up putting the car on the dyno today, made 495awkw on around 25psi, then backed it down to 470awkw at 23psi for a safety margin. Not bad for 98 octane fuel and water meth. 10 degrees of timing for the 470 and 13 for the 495. Forgot to change the scale back to road speed, runs were started at 90kph and 2800rpm and finished up around 200kph. The little dip your see at the end is the car tagging the limiter. Lol it was all done with a boost tee cos I was diagnosing some stuff the other day and hadn't swapped it back to the boost solenoid. The boost stays there due to the fact of the turbo being well within its efficiency range. 2 Link to comment Share on other sites More sharing options...
k31th less WHY; more WOT Site Developer 29,071 Member For: 16y 8m 19d Gender: Male Location: Melbourne Posted 14/09/24 11:23 AM Share Posted 14/09/24 11:23 AM that's a great result considering the fuel issue... Link to comment Share on other sites More sharing options...
Puffwagon Puff Gold Donating Members 15,998 Member For: 9y 11m Gender: Male Location: South Australia Posted 14/09/24 11:40 AM Author Share Posted 14/09/24 11:40 AM The fuel usage is a symptom of something else. Afrs are on point and have been the whole time. There isn't a fuel issue per se. At any rate we'll find out one day. Still gonna take it to roll racing next month and chop the locals 1 Link to comment Share on other sites More sharing options...
Puffwagon Puff Gold Donating Members 15,998 Member For: 9y 11m Gender: Male Location: South Australia Posted 15/09/24 06:13 AM Author Share Posted 15/09/24 06:13 AM Ok so I might not take it to roll racing just yet. I did a trans service today, mainly to see what the fluid looked like. It wasn't great and there was a bit of a sheen to it, like when bushes are wearing or something metallic is wearing. No chunks in the pan and it still shifts fine but considering the extra fuel use, I'm gonna pull the box out and see what's up. As I've said I reckon it's a converter issue but all that will be checked out shortly. Fark me ay, rebuild the engine, get a haltech and I still can't drive the farken thing. 1 1 Link to comment Share on other sites More sharing options...
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