Oh no! Didn't pass smog
10-22-2013, 02:00 PM
#16
Rennlist Member
Thread Starter
By the numbers:
I only use Chevron 91 octane unless I'm somewhere on the planet where there isn't a Chevron station then I use Shell.
Ignition timing shows 21BTDC
15mph
RPM 1499
Meas %CO2 14.0
Meas %O2 0.7
HC PPM Max 198 AVE 40 MEAS 248
CO% Max 1.29
AVE 0.17
MEAS 0.28
NO ( PPM) Max 1304 Ave 520 Meas 942
I only use Chevron 91 octane unless I'm somewhere on the planet where there isn't a Chevron station then I use Shell.
Ignition timing shows 21BTDC
15mph
RPM 1499
Meas %CO2 14.0
Meas %O2 0.7
HC PPM Max 198 AVE 40 MEAS 248
CO% Max 1.29
AVE 0.17
MEAS 0.28
NO ( PPM) Max 1304 Ave 520 Meas 942
10-22-2013, 02:01 PM
#17
Burning Brakes
Hi Van:
Ever replace your O2 sensor? Don't know if that's the problem, but they're cheap for the early cars and easy to replace. As I recall they're supposed to be replaced at ~30k intervals.
Can't hurt....
Ever replace your O2 sensor? Don't know if that's the problem, but they're cheap for the early cars and easy to replace. As I recall they're supposed to be replaced at ~30k intervals.
Can't hurt....
10-22-2013, 02:53 PM
#19
Rennlist Member
Thread Starter
Can anyone explain how acetone effects the gas. Is this similar to using ethanal?
I have new fuel lines etc, so thinking a one time shot wouldn't do all that much damage
Could it?
I have new fuel lines etc, so thinking a one time shot wouldn't do all that much damage
Could it?
10-22-2013, 03:51 PM
#23
Burning Brakes
I take mine to my Porsche Indy to pass smog. He charges me a very small amount to get the car to pass smog test. I remember him showing me he takes the AFM apart and clocks something just a little. But It could be he does this for another reason perhaps. I know there is a strip in there that gets worn and you need to move it a tad to work correctly.
Does this sound right to anyone here for smog testing reasons?
Does this sound right to anyone here for smog testing reasons?
10-22-2013, 04:04 PM
#24
Race Director
Van
How warmed up was the car.......generally speaking 928's prefer HOT weather and a fully warm engine to run best for smog testing..... Even well running 928's will BARELY pass HC is cold in coldish weather....
Ideally do a HARD run on the freeway, full throttle to redline in a couple lower gears then bring it in to the smog shop and get right on the tester.....
My old 88 S4 never failed smog, but barely passed when it sat for an hour in cold weather waiting to test..... two years later fully warmed up passed with flying colors
How warmed up was the car.......generally speaking 928's prefer HOT weather and a fully warm engine to run best for smog testing..... Even well running 928's will BARELY pass HC is cold in coldish weather....
Ideally do a HARD run on the freeway, full throttle to redline in a couple lower gears then bring it in to the smog shop and get right on the tester.....
My old 88 S4 never failed smog, but barely passed when it sat for an hour in cold weather waiting to test..... two years later fully warmed up passed with flying colors
10-22-2013, 04:18 PM
#25
Running acetone at 3oz/10 gal. petro gets you the ideal stoichiometric formula for alleviating all the H-H bonding between the hydrocarbons. It is especially useful in cold weather where complete atomization is almost impossible even with the highest injector pressures. Not only that, it is a fuel and an oxygenate and will burn hotter even in colder temps. I have never had a vehicle fail inspection unless it had bad rings or bad valve guides using this method. If you have bad gas that has gelled from sitting over the winter (ethanol blends are worse). 6oz acetone/10 gal. petro will clean it out.
I ran it in the 944 for years and the 948 LS swap with zero issues. I know the 944 block is the same alloy as the 928 block and it did not harm the A390 alloy, nor did it do anything to fuel lines/injectors/gas tank either.
I ran it in the 944 for years and the 948 LS swap with zero issues. I know the 944 block is the same alloy as the 928 block and it did not harm the A390 alloy, nor did it do anything to fuel lines/injectors/gas tank either.
10-22-2013, 04:41 PM
#26
Rennlist Member
Thread Starter
I had not driven it for the past 10 days as I was on the east coast and the smog station is not that far from where I live and the traffic getting there was bad, mostly 3rd gear stuff. My car is not a garage queen. not afraid to put miles on it.
In my road racing life ..I didn't but others used propolene dioxide with race gas to get a few extra hp's. It went into 2 hour Lotus twincam motors. Guys with big big budgets used it.
Twincams on meth
I have MSDS headers. my next mission is to take the sensor out and see what it is
In my road racing life ..I didn't but others used propolene dioxide with race gas to get a few extra hp's. It went into 2 hour Lotus twincam motors. Guys with big big budgets used it.
Twincams on meth
I have MSDS headers. my next mission is to take the sensor out and see what it is
10-22-2013, 04:43 PM
#27
Former Sponsor
By the numbers:
I only use Chevron 91 octane unless I'm somewhere on the planet where there isn't a Chevron station then I use Shell.
Ignition timing shows 21BTDC
15mph
RPM 1499
Meas %CO2 14.0
Meas %O2 0.7
HC PPM Max 198 AVE 40 MEAS 248
CO% Max 1.29
AVE 0.17
MEAS 0.28
NO ( PPM) Max 1304 Ave 520 Meas 942
I only use Chevron 91 octane unless I'm somewhere on the planet where there isn't a Chevron station then I use Shell.
Ignition timing shows 21BTDC
15mph
RPM 1499
Meas %CO2 14.0
Meas %O2 0.7
HC PPM Max 198 AVE 40 MEAS 248
CO% Max 1.29
AVE 0.17
MEAS 0.28
NO ( PPM) Max 1304 Ave 520 Meas 942
These early cars, in California, can make people crazy....including me.
It would be really handy if you could scan the entire test results and post the entire thing....drawing conclusions from 1/2 of the information is tough.
However, those test results, if you have typed them correctly, would indicate that the car failed HC. Your CO appears to be fine. The NO is slightly high, which is pretty "normal" for these early vehicles....and if you make the engine any leaner (new O2 sensor), the NO will likely go up.
High HC is almost always a misfire condition.
10-22-2013, 05:11 PM
#28
I had not driven it for the past 10 days as I was on the east coast and the smog station is not that far from where I live and the traffic getting there was bad, mostly 3rd gear stuff. My car is not a garage queen. not afraid to put miles on it.
In my road racing life ..I didn't but others used propolene dioxide with race gas to get a few extra hp's. It went into 2 hour Lotus twincam motors. Guys with big big budgets used it.
Twincams on meth
I have MSDS headers. my next mission is to take the sensor out and see what it is
In my road racing life ..I didn't but others used propolene dioxide with race gas to get a few extra hp's. It went into 2 hour Lotus twincam motors. Guys with big big budgets used it.
Twincams on meth
I have MSDS headers. my next mission is to take the sensor out and see what it is
Not to slightly hi-jack but what about visual on the headers?
tino
10-22-2013, 05:33 PM
#30
Former Sponsor
Good.
You can see that you also barely made the limit on HC at 25mph. On multiple tests, that is close enough that it might go over the limit, also.
HC is actually the measurement of unburned fuel....so incomplete combustion. Could be as simple as a new set of spark plugs with the correct heat range. Obviously, check compression, when the plugs are out. Look at the condition of the plug wires, things like that. Look around for deteriorated vacuum hoses.....things that can cause a misfire.
You can see that you also barely made the limit on HC at 25mph. On multiple tests, that is close enough that it might go over the limit, also.
HC is actually the measurement of unburned fuel....so incomplete combustion. Could be as simple as a new set of spark plugs with the correct heat range. Obviously, check compression, when the plugs are out. Look at the condition of the plug wires, things like that. Look around for deteriorated vacuum hoses.....things that can cause a misfire.