Failed Smog -- Slightly High HC on the dyno UPDATE

[2ndtimearround]

Took the GW to the Smog Nazis tonight. :mad:

Interesting results:
ASM2525 Test (1225 rpm):
HC ppm Limit 96 -- Reading 102 failed by 6 ppm!!
CO% Limit 0.53 -- Reading 0.11
NO ppm List 1027 --Reading 224

Curb Idle (674 rpm):
HC ppm Limit 300 -- reading 196
CO% Limit 1.50 -- reading 0.87

I know that a high HC usually means unburnt fuel. But wait I have great readings at idle, but not on the dyno. Any ideas?

BTW this is a Canadian GW, which means only an EGR, no cat and no air pump.

Lawrence

[ March 30, 2003, 03:04 PM: Message edited by: 2ndtimearround ]

[letank]

your idle CO is a bit high......(too rich) ideal is about 0.05

is your choke really opened

clean air filter

but i think that your power valve may be leaking a bit, when is the last time your rebuilt the carb

disconnect hose to the power valve somewher where it is convenient, connect a transparent hose and use a vaccum gauge to see if you can sustain a moderate vaccum without sucking gas.... i am sure you will have gas coming... and probably gas in the hose when you disconnected it

Michel

[az mike]

use high octane feul and a bottle of rubbing alcohol then then try it the next day thats what i used to do when i went thru and faild then it would pass

[Kaiserjeeps]

I have only heard this but never tried it. My rigs are too old for emissions. I heard that when you are failing for hydrocarbons that you can change to synthetic oil which has no hydrocarbons in it. It should burn cleaner. Regular oil is hydrocarbon based. On the other hand you are so close to passing, maybe try a good run down the freeway to heat things up beforehand. Good luck, it will pass....

[az mike]

ya i forgot to mention to run it hard down the freeway a little to before hand

[RWalker]

Has a tuneup been done recently? When was the last time the sparkplugs were replaced?

[2ndtimearround]

I did the TFI converstion during the winter (not driven at all after) with new plugs, rotor, cap, wires, TFI coil. Plus all new fluids and filters.

I am going to do the test Michel suggested once the rain stops today. I have some drivability issues that point to the power valve as well.

Probably time for a carb rebuild. Thanks for the suggestions -- I will give an update with the results of testing the power valve.

I talked to a Speed shop that is also a Emissions repair facility -- he suggested the "dry fuel" additive (alcohol) :D and a very good warm up.

I also found out that they are droping the visual inspection part of our emissions testing -- as long as you have the numbers you pass. Time for EFI!

Thanks for all the suggestions.

Lawrence

[2ndtimearround]

First thanks to Michel. I did the test he suggested -- the power valve was bad! I could not believe how much it was leaking -- gas was even coming out the rod that operates it.

I picked up a rebuilt carb (cost difference between factory rebuilt and master rebuild kit was only $25.00, plus the rebuilt came with the a new dashpot, electric choke and idle stop solenoid :D )

When I went to install it today I found that the carb spacer was broken, DPSO must have broken it and just bolted it back on, and I had some very bad vacuum lines around the carb. I cannot wait to check my vacuum when I get it running -- it was drawing 17 in with the leaks!

The DSPO screwed up the gas line to the carb as well it was badly crimped where he bent it.

When I removed the carb, the power valve was dumping gas into the manifold. I am surprised it was not flooding.

I replaced the vacuum lines, plus installed a new gas filter.

Tomorrow I will be ordering the carb spacer and oven for the choke. Plus I am going to put a new EGR valve on while I can easily get to it!

I will be changing the oil (some gas dilution?) before the next emissions test.

What a great way to spend a Sunday afternoon.

Again thanks for all your suggestions. Again this list proves how good it is. :D :D

Lawrence

[ March 30, 2003, 03:26 PM: Message edited by: 2ndtimearround ]