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Failed CA SMOG any ideas

suntadz

suntadz

1/2 ton status
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Location
bay area, ca
Ive been having engine troubles and thought someone could help. Last year I got a crate motor with a comp cam 12-249-4 kit, 1.5 rockers, edlebrock intake, bored TBI with Adj reg, powercharger, headers, your stage 2 chip,and MSD dist/coil. I never really thought it had much more than stock but the guys who put it toghter for me said it was good. Well a year later both heads are fried with exhaust vavle seat damage. They blamed the Comp springs saying they were weak only have 45lbs of seat pressure and floated the valves to beat up the head. They fixed the head and shimmed the springs to get the proper 110 seat pressure. They did tell me awhile back they thought it was detonating and I should run a better gas. Anyway I just got it back yesterday and it was due for a smog here in CA. It did not pass and they guys there told me it was running extermely lean. I have some smog data if it would be helpful. Anyway I replaces the O2 and the cat is only a year old. I figuring they guys who built my engine did not tune my TBI properly and it must be out of whack.
Here are the smog finding. Can anyone help?
 

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  • Smogg.txt
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The numbers come across all jumbled up and I cannot tell what you failed. What was actually out of spec on the printout or did they fail you on visual?

Dik
 
heres a little trick

we sell cars at my dads shop and smog is a big issue for us so here is a little trick i know of that works like a charm for us. go to your local market and pickup two bottles of 91% or higher rubbing alchohol preferably 97%. fill your tank to halfway with 91 octane or higher. mix the two together and take it to get smogged. the trick is that alchohol runs cooler and cleaner than regular fuel. this is not a fix all and if your truck is running poorly ( if i could see the stats i would already know) fix the problem. most custom built motors dont do well with smog but just out of curiosity have you checked to see if you have a vacuum leak, if so that would cause you to run lean at idle and would not trigger your vacuum advance (if your truck is so equiped) which would cause multiple issues with smog and driveability. this is the trick i use to beat the CA smog issues with my own vehicles
 
hmmm
seems to work for me but here are the smog stats. Instead of just passing I really want to fix the problem.

15mph test 25mph test
CO% 14.6 CO% 14.7
O2% .7 O2% .6
HC max 113 HC max 93
GP 300 GP 250
meas 9 meas 8
CO max .62 CO max .81
GP 1.92 GP 2.11
meas .03 meas .03
NO max 980 NO max 840
GP 1750 GP 1550
meas 1864 meas 1518

Anyone make sense of this?
 
If the smog guy says it's running lean than that's the problem.

It's tough to tell why it's running lean, but it could be low fuel pressure, or any number of issues.

I'd post the winaldl datalog in the injection section and see if anyone can tell what's up.
 
Sell it an replace with a smog exempt 75' and older year, Put that crate motor in it. It's the easiest way :D. I hope to own nothing but smog exempt rigs some day, even if there newer re re-regestered rigs. Anyone want to buy a 06' 2500 HD for way more then it's worth. :haha:no really?
 
yea i got to figure out how to work the winaldi program...and get a laptop.....

i was thinking of fuel pressure. i checked for vacuum leaks. also could be the egr but i replaced alot of it last year when i put the engine in.
 
It sounds like it's just really far out of tune. You'll have to diagnose it and see. At least check the fuel pressure and the filter. EGR is supposed to help with detonation so I'd check that too and not assume it's good just because it's newer.

I don't know much about the cam or the other modifications, but it's possible that you won't be able to do anything if the cam is too aggressive or the chip mods are too far from stock. If you can find another motor with similar specs that's running properly, you might be able to smog that and see how far off yours is.

If the DMV is labeling it as a "gross polluter" it's pretty far off from being able to pass.
 
yea... tomarrow ill mess with the fuel pressure and see. Im not sure how to check the EGR but looks like Im due to find out.
 
Where in the bay area are you? Also, if it failed as a gross polluter you now get to smog it EVERY YEAR for the next 4 years, Lucky you. I don't mind helping you try to figure it out if you're close enough to come see me. I have both a laptop with the winALDL program and also an OTC scanner.
 
Yep that helped me understand it now:D. The NO is high. This is from running lean which jacks the cylinder temps up and creates higher levels of NOx. The increased temps also cause detonation. The detonation can be helped with timing but like most have said earlier it is most likely a bad tune. If the motor is as hot as the "builder" says it is you most def need a chip to put more fuel in which would solve your lean issues.

Keep in mind this is all just speculation on my part as we do not have any concrete numbers from a data log to go by. Just shotgunning so you have areas to look into.

Dik
 
First of all you have a very mild cam, i dont see how , with the proper comp springs you should have any issues with spring presure, Sounds like your engine builder is giving you a line of BS to me. Shoot you could get away with running that cam on stock springs.
Second. A stage 2 chip? WHY???? Most aftermarket stage 2 chips require a 160 degree thermostat. What t stat is in your truck? Even with a 160 T stat they run a little lean because they jack the timing up too much and dont give enough fuel (unlless you increase the fuel pressure). If you have a 2 chip and are running a hotter t stat than 160 then it will cause the problems you are having. like detnotation and tearing up the valve seats.
You would be better off with the stock chip, 180[for performance] 195(best to pass smog) degree T stat, fuel pressure around 12-13 PSI. timing set at 0 BTDC.
How big is the TB bore?
 
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i forgot the specs on the bore of the TB. It was just a bit not much if i remeber it matched the intake mainfold at 47mm i believe. Yea I have a 170 thermostst in it but bought a 180 i was going to put in it today. Maybe ill swap the chips back too and see what happens. I would also like to get the winaldi thing so I can see about maybe geting a chip that will work for me then.
 
NO is definitely high. check the EGR valve.

Disconnect the vacuum line from the valve while the truck is idling and hook up a vacuum pump. when you draw a vacuum the egr valve should open and allow exhaust into the intake. This should cause the motor to either die or seriously stumble.

If it does not..the valve is either bad or the egr passage is plugged....

If it does die...we will need to investigate further.


Cheers,

Rufus
 
The EGR on TBI trucks is a backpressure type and you cannot open them with a vacuum pump like the older style EGR valves.
 
Was looking up some info in the testing procedure for EGR on a back pressure system. here is an excerpt from what I found:


"[SIZE=-1]The positive back pressure EGR valve can be identified by the letter "P" stamped next to the part number and date code. A back pressure valve is easy to spot because its pintle shaft is much thicker than the single diaphragm type. This is so because the shaft is hollow. The hollow design allows exhaust gases to flow into the shaft and push up on it. When positive back pressure in the exhaust system is sufficient, the shaft raises up and seals the built-in control valve. Once the control valve is closed, it allows applied vacuum to pull up on the diaphragm. Without back pressure to lift the hollow shaft and close the control valve opening, the EGR valve will not hold vacuum. It is bled off to the atmosphere. This design thus modulates EGR flow by modulating the applied vacuum. As engine load increases, so does engine back pressure, which causes the control valve inside the EGR to trap vacuum and open up. To test this valve, bring the engine up to 2,000 rpms to create back pressure, then apply vacuum. EGR should open and cause a 100 rpm drop or more. Exhaust leaks or a modified exhaust system can create havoc here. Adding dual exhaust or headers on a car designed for a single exhaust will reduce back pressure and set a Code 32 on GM cars. Positive back pressure EGR valves are used in simple vacuum controlled systems, as well as more complex pulse width modulated applications."


This may not be exact for your vehicle but the general procedure should be sound.

Hope that helps.

Cheers,

Rufus
[/SIZE]
 
well i replaced the thermostat with a 180 degress, O2 sensor, swapped back my stock chip, and screwed the needle in a bit on the adj fuel pressuer reg. Went back down and it passed. borderline on some areas but it passed. I do notice it runs a bit more bogged down it seems and hesitates a bit. Not sure where to go from here but i guess finding out the winaldi readings is the best place to start. thanks for the help.
 
Not sure where to go from here
Click to expand...
I do, learn to tune your own chips! :p: Sounds like you "tuner" only did half the job. Just from reading you post, it sounds like you need to drop you blm counts at idle and retard the timing at idle. I'll also bet that the timing curve is waaaaay to steep for your setup and that the fuel curve is off too. You should be able to run that setup with a 170 or 180 degree thermostat and regular fuel.
 
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