This is topic 90 mustang wont pass smog high HC in forum Tech Talk at Northern California Ford Owners  .


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Posted by Jeff H (Member # 13341) on :
 
Hi all,my 125k mi mustang fails on the dyno @15mph test.I've got the usual bolton's ,gt40 heads non AIR inj,tfs1 cam, tfs springs, 1.5 rollers,explorer egr intake,bbk shortie headers,stock air cleaner&boot 70mmC&S 19 lb injectors.65 mm tb. Air system in place, but non functional through heads stock 4 cat H pipe. Timing set @10 deg any ideas??? runes great! fun to drive, just can't get it to pass smog... thanks in advance...


well looks like I lost my img hosting... [Roll Eyes]

[ 2017-09-09, 01:03 AM: Message edited by: Jeff H ]
 
Posted by Martinna (Member # 12493) on :
 
Your HC is too high. Do you have a chip? Without exception set your timing to 7 degrees for smog tests. Lower timing lowers your HC and NOx! Make sure your ignition system is in good order. Drive the car around for a long time on a hot day before smog testing. Let the car idle while at the shop. Keep it warm. Do not use a 160 thermostat.
 
Posted by 4IDFOX (Member # 9921) on :
 
Get another spout connector plug in. Break off one of the metal tabs inside. Plug it in. Timing will be locked at base setting. HC's will be lower.

Plus everything in post above

[ 2017-09-08, 04:50 PM: Message edited by: 4IDFOX ]
 
Posted by Martinna (Member # 12493) on :
 
4IDFOX ---- yes. Timing should be at 13 degrees for this trick. Be careful. Headers will glow red and melt plugs and wires if you jump on it or drive around too long with out the spout.
 
Posted by Jeff H (Member # 13341) on :
 
quote:
Originally posted by Martinna:
Your HC is too high. Do you have a chip? Without exception set your timing to 7 degrees for smog tests. Lower timing lowers your HC and NOx! Make sure your ignition system is in good order. Drive the car around for a long time on a hot day before smog testing. Let the car idle while at the shop. Keep it warm. Do not use a 160 thermostat.
No, no chip, one thing you did point out was the t stat,when I overhauled it I did put a 160 in it. Bad move huh? I'll go buy a the 195 it came with & reinstall I just wanted it to run a little cooler on warm days. Another thing that was pointed out was do an oil change as the oil carries contaminates that will elevate hc levels. The car sat for almost two years & I had about about 1500mi on the oil change when I parked it. it has fresh oil in it now .
 
Posted by Jeff H (Member # 13341) on :
 
quote:
Originally posted by 4IDFOX:
Get another spout connector plug in. Break off one of the metal tabs inside. Plug it in. Timing will be locked at base setting. HC's will be lower.

Plus everything in post above
copy that thanks...
 
Posted by 4IDFOX (Member # 9921) on :
 
Just the stat change will probably help you pass.
 
Posted by Martinna (Member # 12493) on :
 
Listen to 4IDFOX. You didn't fail by much. 7 deg timing. Change the stat. Hot day with a hot engine. High HC means you're not burning up all the fuel. Everything hotter and less timing will burn more fuel to lower your HC numbers. Share your new smog numbers after you do these items so everyone can see the improvement.
 
Posted by 4IDFOX (Member # 9921) on :
 
I re-read you post about changing your oil. That alone may make you pass. But you definatly want a 195 t-stat. You should never go for a smog check without an oil change.
I took a track car for a smog check once that only had a couple track days on the oil I was lazy thought it would be ok. Was a gross polluter. Changed the oil and it passed.
 
Posted by Jeff H (Member # 13341) on :
 
Update:

well, it passed,barely. after changing the oil, putting the 195 t stat back & making sure the timing was set at 10 degrees,I got it real hot on the freeway driving to the test only station.I also let it sit & idle before the test to keep the cats hot.On the HC(PPM) 85 is Max it measured 84 at 15 MPH and that is with a stock air cleaner,a pair of non air inj ported gt40 iron heads,all the emissions equip is there for visual only.A tfs-1 cam,explorer intake & throttle body& bbk headers.Now time to put it back theway it was. What a hassle, but necessary for the fun factor! I honestly don't know if it'll pass again in two years.It seems like the smog Nazis want these cars off the road period...

[ 2017-09-26, 01:17 AM: Message edited by: Jeff H ]
 
Posted by Martinna (Member # 12493) on :
 
You should have ran 7 degrees timing to pass easier. Nothing lowers NOx and HC more than retarding timing. You can still pass with 7 degrees timing. Everyone should run 7 degrees timing for smog. It'll pass again in 2 years if you lower the timing.

[ 2017-09-26, 01:54 AM: Message edited by: Martinna ]
 
Posted by Jeff H (Member # 13341) on :
 
quote:
You should have ran 7 degrees timing to pass easier. Nothing lowers NOx and HC more than retarding timing. You can still pass with 7 degrees timing. Everyone should run 7 degrees timing for smog. It'll pass again in 2 years if you lower the timing
Noted for next time, thanks...

[ 2017-10-28, 10:58 AM: Message edited by: Jeff H ]
 




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