well its time for my state inspections yet again. the car passes the high speed sniff test without a problem but at idle it is way off (max HC=220 and min is like 620). i put some new plugs in yesterday and still it failed. what could be causing this? the IAC and O2 are fairly new, no more than 6 months. the reason i changed the plugs was because i had a miss, it doesnt sound like it is missing anymore. anyone else have this problem? oh yeah car is the 89 in the sig

------------------
Brandon
"ScreaminDeamin 360"
350 60 over, TRW forged 9.83:1 pistons,Hooker Comp headers, crane cam 216/228 .484/.512, crane 1.6 RR's, ported plenum, home made ram air, 24lb SVO injectors, crane AFPR, all going through 3 inch mandrel pipe and a flowmaster.
New project-89 IROC-305 5spd...Jamex Springs...and thats just about it!Soon- 6 speed, Pro 5.0 shifter and 4.10's

http://ScreaminDeamin.cz28.com

 

Do you have a custom chip? Its probably the injectors making it run rich, try dropping the fuel pressure and see if that helps at all.

 

have your chip tuner idle the engine @ 750rpm
he can change the injector constance +.5-1
# on injectors to lean the whole car down.
reconfigure the CID and rebalance for the vacuum
loss at idle because of cam. adjust timing to
10*. your probably idling 600rpm drive and park.
that should bring you down to 300ppm. maybe
better...
airdeano

 

this is the 89 Iroc it is completely stock, thats why i am trying to get it inspected b4 i put the other motor in my sig in. the ppm right now is at like 620HC i need to get it down to at least 220ppm HC.

------------------
Brandon
"ScreaminDeamin 360"
350 60 over, TRW forged 9.83:1 pistons,Hooker Comp headers, crane cam 216/228 .484/.512, crane 1.6 RR's, ported plenum, home made ram air, 24lb SVO injectors, crane AFPR, all going through 3 inch mandrel pipe and a flowmaster.
New project-89 IROC-305 5spd...Jamex Springs...and thats just about it!Soon- 6 speed, Pro 5.0 shifter and 4.10's

http://ScreaminDeamin.cz28.com

 

D*mn Emissions. I would do this:

#1. Try advancing your base timing ... a lot. This will give your engine more time to burn the excess fuel, but don't punch it until you get it home and reset the base timing or you'll detonate (not a big deal if your knock sensor works)

#2. I'd toss some 19 lb injectors in, or even go to a junk yard and yank some 16 lb jobs off a 2.8 (If they fit) and drive it to the testing facility before the computer knows it's injectors are way undersized. Just make it run lean.

#3. Try throwing a high voltage coil on there. Maybe you have a bad spark module. Maybe you aren't even burning the fuel in one of the cylinders.

#4. Put a 220 thermostat in. GM kept the operating temperature of their vehicles high to burn off hydrocarbons. Make sure you are at operating temp when you cruise through.

Never had emissions here in Ohio. Let me know if it helps.

------------------
355 c.i.
Dart 180 Heads
Lunati 224/224 cam
Harland Sharp 1.5 rockers
Performer RPM Manifold
Holley 600 cfm double pumper
Hooker Super Competition Headers
Flowmaster Exhaust
Competition Engineering Sub-frame connectors
Super T-10
GM posi 3.42 rear
Hurst Roll Control
13.9@102

 

Is your AIR system in good working order? How about the cats?

------------------
1990 IROC 350
Mods: Too busy trying to make it run right to mod it.
Airfoil, Dynomax cat-back, MSD coil, 180 t-stat, Bald Eagle tires,
Hypertech fan switch, Accel 23# injectors, Holley module, ported plenum,
Ported Daytona Yellow stock base, Moroso valve covers, other stuff,
Streetdampr, Ruger P95DC, hot wife, new oil filter, !cats, !TBC, !AIR.
18.0 @ 85MPH since I'm one big-a$$ MF
"It's better to have and not need than to need and not have."

 

making the car lean will only make you fail for NOx.

------------------
1990 Pontiac Formula 350
Rebuilt 355
COMPCAMS 212/212 .440/.440 cam
Flowmasters 80 series.