Failed smog. need help with hydrocarbons!!

[birel21y]

Hey guys. Finally smogged my new setup. Failed overall from being over on hydrocarbons. I believe I'm running super lean. Could this make my hydrocarbons. High? Also I was going to retard the timing and possibly add an additive to the fuel. I have a killer ignition system, so that shouldn't be it. Also, I have a studder going on at part throttle (1/8)-(1/4) throttle. The car wants to buck at low rpms. I have a really bad idle surge as well. Any info helps guys. Thanks

 

[CC'S95GT]

hydrocarbons is excess fuel. (too rich) not lean.
Start with the basics - tune up, clean maf,and Iac.
I pull the spout before I get mine sniffed. The PO had NOS and had it tuned for the juice so mine is rich too.
With the spout pulled the puter doesn't advance the timing. the car will run on base timing but it won't rev over 2500-3000 rpm's.

 

[birel21y]

Everything is new on the engine, so it must be a tuning issue. Any ides?

 

[NERD]

Run race gas for your test.

 

[Paul]

Run race gas for your test.

Huh? Why would that help?

 

[birel21y]

I may have a vacuum leak. I can't get the ide less than 800 with the iac unplugged and with the throttle screw adjusted all the way down. Is there any way to pressurize the intake to find a leak? Any other easy way to find leaks?

 

[pp_puncher]

with the car running spray starter fluid slowly around the intake mating surfaces, if the rpm's go up there's your leak.

 

[birel21y]

I tryed carb cleaner, starting fluid, propane, etc. Finally I found that blowing pressurized air through a vacuum line worked best, then spraying soapy water everywhere produced bubbles where the leaks are. Found that my trick flow nitrous plate has a leak around where the line enters.. now my question is, it there any simple way to get my air/fuel ratio correct without buying a widband gauge??

 

[Mstang96]

Well i failed with my tune as the tune slightly leaned out my car and caused alot of Nox and failed my smog. Returned to stock and passed....

 

[pp_puncher]

I tryed carb cleaner, starting fluid, propane, etc. Finally I found that blowing pressurized air through a vacuum line worked best, then spraying soapy water everywhere produced bubbles where the leaks are. Found that my trick flow nitrous plate has a leak around where the line enters.. now my question is, it there any simple way to get my air/fuel ratio correct without buying a widband gauge??

Seal up that leak and that should help, also the wide band gauge is just that...a gauge, it won't fix anything.

 

[birel21y]

Well how do tuning shops tune obd1 cars like mine? If I got a wideband AF gauge, would I be able to get my car at least close to correct?

 

[pp_puncher]

the gauge will just show where your a/f is at. if you want it changed you have to adjust timing and fuel for given maf counts. Tuner use sct chips or software like megasquirt and such.