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Unless I’m doing something wrong, smoke test revealed nothing. I put a latex glove over the throttle body and pumped smoke in. Nothing. Any tips or tricks to doing the smoke test on these cars that I should be aware of?
If you smoked the intake and didn't see any obvious leaks, then you could also smoke test the crankcase through the oil fill. Conversely, you could just replace the oil fill tube and cap as that's the #1 source for vacuum leaks on 996/997 models.
As already mentioned, it may be time to replace the injectors.
Might as well do the gas cap as well as they do go bad and if it's still the original one, it's not a bad idea to replace it.
At that point, the primary o2s and MAF sensor could be replaced as they affect fuel trims. Lastly, don't forget to do a system adaptation (vehicle handover) when you make any large change like swapping out sensors or injectors.
I’ll smoke test the oil fill tube tomorrow and address as needed. Trying to decide if I want to DIY the injectors myself or farm that out. Not a lot of room back there and I haven’t found a good DIY guide (haven’t looked too hard yet). If I decide to DIY how does one accomplish the system adaptation?
Durametric cannot do a vehicle handover so you would accomplish it by paying a dealer (or anyone you know with a PIWIS) to perform the operation on your vehicle.
The fuel % is trending upwards. If the next sample is higher yet again, you should probably address it, but otherwise, looks great. Normal fuel dilution for the DFI motors is closer to 0.5%.
I thought higher fuel dilution is expected in DFI motors. At least based on LNE videos I’ve watched. Could be older videos, I suppose. Don’t remember when they were published.
I thought higher fuel dilution is expected in DFI motors. At least based on LNE videos I’ve watched. Could be older videos, I suppose. Don’t remember when they were published.
Higher is the 0.5%. Non DFI motors show zero or TR for trace amounts.
Normal fuel dilution for port injected would be under .5% and under 2% for DFI.
just ignore blackstones fuel dilution. The measurement is garbage.
Spot on. I just ran this by Lake Speed Jr. and he said the same.
Blackstone's fuel % number is a best guess. It's not accurate.
SPEEDiagnostix actually runs a separate GC test to accurately calculate fuel %. Most of the variances in fuel % numbers are due to the difference between using flashpoint vs gas chromatography.
Spot on. I just ran this by Lake Speed Jr. and he said the same.
Blackstone's fuel % number is a best guess. It's not accurate.
SPEEDiagnostix actually runs a separate GC test to accurately calculate fuel %. Most of the variances in fuel % numbers are due to the difference between using flashpoint vs gas chromatography.
Charles,
Off topic but I thought to ask because its related to fuel injectors. I read that the recommendations for fuel is to use a top tier brand but also ethanol free premium is recommended also. Here in southern Wisconsin we have 93/with ethanol or 91 ethanol free. Almost always are the top tier fuels 93 ethanol. I usually fill with the ethanol free gas but would like an informed opinion. Would you recommend using 93 ethanol top tier or 91 name brand (Shell, Mobil) ethanol free?
Also, I just switched from M1 5w50 to driven DI 40 during my latest oil change in my 997.2. Should I expect any increased wear or anomalies at my next oil change while the additive packages clash and sort themselves out?
Thanks in advance for your advice.
Last edited by Prairiedawg; 10-30-2022 at 01:21 AM.
Off topic but I thought to ask because its related to fuel injectors. I read that the recommendations for fuel is to use a top tier brand but also ethanol free premium is recommended also. Here in southern Wisconsin we have 93/with ethanol or 91 ethanol free. Almost always are the top tier fuels 93 ethanol. I usually fill with the ethanol free gas but would like an informed opinion. Would you recommend using 93 ethanol top tier or 91 name brand (Shell, Mobile) ethanol free?
Also, I just switched from M15w50 to driven DI 40 during my latest oil change in my 997.2. Should I expect any increased wear or anomalies at my next oil change while the additive packages clash and sort themselves out?
Thanks in advance for your advice.
Why were you running a 15/50 in a 997? That's way too thick a cold viscosity.
10-15-2022, 11:43 PM
