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Hydrocarbons too high to pass emissions. Need help!! by zmcdonal
Started on: 07-10-2013 05:34 PM
Replies: 16 (505 views)
Last post by: armos on 07-16-2013 03:12 AM
zmcdonal
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Report this Post07-10-2013 05:34 PM Click Here to See the Profile for zmcdonalSend a Private Message to zmcdonalEdit/Delete MessageReply w/QuoteDirect Link to This Post
My Fiero is not passing emissions this year. I took it through yesterday and they do an idle test on it because it sits so low they don't think they can run it on the rollers.

Yesterday's #'s
Hydrocarbons 318 standard 220
Carbon monoxide .19 standard 1.2

When I got home I put a new O2 sensor in it that I know only had a couple thousand miles on it from my parts car (which ran great, only parts car due to rust) . With the new O2 sensor the car seemed to idle smoother and drive a bit smoother as well. Took it back to emissions today only to fail with an even higher hydrocarbon #.

Today's #'s
Hydrocarbons 394
Carbon monoxide .19

My car is an 87 with a 2.8 that's been rebuilt a few years back. About 50,000 miles since the rebuild. Blue printed and balanced, mild cam (was a cali car so had to pass smog there), ported intake exhaust heads, SS valves bigger injectors, 7730 computer installed by sinister performance, digital egr.

Passed emissions two years ago with flying colors. Nothing new mechanically since then.

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Report this Post07-10-2013 05:57 PM Click Here to See the Profile for trotterlgClick Here to Email trotterlgSend a Private Message to trotterlgEdit/Delete MessageReply w/QuoteDirect Link to This Post
Cold start injector leaking? Is it getting up to operating temperature?
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zmcdonal
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Report this Post07-10-2013 06:04 PM Click Here to See the Profile for zmcdonalSend a Private Message to zmcdonalEdit/Delete MessageReply w/QuoteDirect Link to This Post
I don't believe it has a cold start injector anymore with the 7730 computer. Not sure about up to temp because I recently did the temp gauge fix switching the wires and since then my temp gauge has not worked. I think I need a need sending unit. Always got up to temp when my gauge was working though.

Plugs wires cap and rotor 17,000 miles ago.

[This message has been edited by zmcdonal (edited 07-10-2013).]

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Raydar
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Report this Post07-10-2013 06:25 PM Click Here to See the Profile for RaydarClick Here to Email RaydarSend a Private Message to RaydarEdit/Delete MessageReply w/QuoteDirect Link to This Post
Connect a scan tool and see what the ECM thinks the coolant temp and intake air temp is. If any of the readings are obviously cold, it will tend to make the engine run rich.
Check your PCV valve, and make sure it's not stuck open. You could be sucking excessive oil vapors out of the crankcase, and burning them.
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zmcdonal
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Report this Post07-10-2013 06:51 PM Click Here to See the Profile for zmcdonalSend a Private Message to zmcdonalEdit/Delete MessageReply w/QuoteDirect Link to This Post
Where could I get access to a scan tool? I know the fiero store sells the software and the thing to link it to a lap top but that's $114 and I only have until the 28th to get it fixed so I don't really want to wait on shipping.

I'll check the PCV and Prob just throw a new one in anyway.

I plan to clean the throttle body and the IAC as well.
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zmcdonal
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Report this Post07-10-2013 11:20 PM Click Here to See the Profile for zmcdonalSend a Private Message to zmcdonalEdit/Delete MessageReply w/QuoteDirect Link to This Post
Well I spent part of the evening working in the car. Cleaned my drop in k&n filter, was much dirtier then I expected. Apparently those quarter panel scoops let a lot of debris in. Cleaned up the throttle body and all cleaned up the IAC.

Took it for a drive afterwards and I don't think it's run that we'll since I've owned it. It idles smooth as glass. I think the O2 sensor has been going out or lazy since I've owned it.

I'm starting to think I need a new cat though. I know that an engine running to rich or with malfunctioning sensors can take a cat out of significantly shorten the life, how can I tell if the cat is bad?
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Report this Post07-10-2013 11:27 PM Click Here to See the Profile for trotterlgClick Here to Email trotterlgSend a Private Message to trotterlgEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
how can I tell if the cat is bad?


It won't pass emissions?

[This message has been edited by trotterlg (edited 07-10-2013).]

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armos
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Report this Post07-11-2013 10:45 AM Click Here to See the Profile for armosSend a Private Message to armosEdit/Delete MessageReply w/QuoteDirect Link to This Post
You might not have a functioning cold start injector with a 7730, but is it physically present with a connection to the fuel rail?
I'd always do at least new plugs before an emissions test. In your case maybe also cap and rotor, unless you're sure they're still very good.

 
quote
Originally posted by zmcdonal:
I'm starting to think I need a new cat though. I know that an engine running to rich or with malfunctioning sensors can take a cat out of significantly shorten the life, how can I tell if the cat is bad?

Supposedly a good cat should have a temperature rise of something like 100F from inlet to outlet of the catalyst. This can be checked with an infrared thermometer. I never saw that on mine though, even though it was new and aced the test, so I'm not sure it's a good test.

If you want to try again, make sure the cat is hot before the test, and you could try retarding the ignition timing a bit to encourage a hotter exhaust. I don't know if that makes sense for you or not. I don't know if your state checks timing or makes you pay for each test attempt.
If you can't find anything else wrong, a new cat would probably make a huge difference.

[This message has been edited by armos (edited 07-11-2013).]

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zmcdonal
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Report this Post07-11-2013 12:20 PM Click Here to See the Profile for zmcdonalSend a Private Message to zmcdonalEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by armos:

You might not have a functioning cold start injector with a 7730, but is it physically present with a connection to the fuel rail?
I'd always do at least new plugs before an emissions test. In your case maybe also cap and rotor, unless you're sure they're still very good.



Not sure if the cold start injector is still present or not.

Really? You always do new plugs before emissions? I know Cali is the most strict of all states but I thought plugs were supposed to last a decent amount of time. I did consider cap and rotor though, especially since I am running the MSD higher output coil and MSD 6AL box, so I know it would burn through caps and rotors faster then the normal. I took the cap off yesterday, it didn't look bad. Might be worth it to spend $25 or whatever it is for a new one though. Couldn't hurt, or maybe it could LOL, like the O2 sensor did.

[This message has been edited by zmcdonal (edited 07-11-2013).]

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armos
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Report this Post07-11-2013 10:13 PM Click Here to See the Profile for armosSend a Private Message to armosEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by zmcdonal:
Not sure if the cold start injector is still present or not.

If it is, you just want to be sure it's not leaking fuel to the intake.

 
quote

Really? You always do new plugs before emissions? I know Cali is the most strict of all states but I thought plugs were supposed to last a decent amount of time.

We get tested every 2 years, and I use the standard copper R42TS plugs so I just schedule them before emissions. Actually I change them every year, which is probably overkill in terms of wear, but I'm a little paranoid about the plugs on the firewall side getting seized. It seems that happens to some people, from what I've read. I don't find them very hard to change so doing it frequently doesn't bother me.

The allowed limits on CA tests are getting ridiculous. What used to pass on a Fiero around 2000, is now considered a "gross polluter" result.
If I ever have to buy another catalyst, I'm thinking about keeping the old one for daily driving, and preserving the new one for tests only. Since my exhaust uses clamps they shouldn't be very hard to swap.
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zmcdonal
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Report this Post07-13-2013 08:45 PM Click Here to See the Profile for zmcdonalSend a Private Message to zmcdonalEdit/Delete MessageReply w/QuoteDirect Link to This Post
Got it to pass yesterday! Took it to the shop I use and they hooked it up to their fancy diagnostic machine that uses an exhaust probe to track emissions levels. Turns out my ignition timing was pretty off. He said it wasn't even close to the mark. He also said my cat was burnt out but that he thinks we can get it to pass without installing a new one.

With the 7730 computer you need to disconnect a wire by the distributor to put the ECM into base timing mode in order to set the timing. They told me to unplug that connector before the test and run it through and reconnect it afterwards. My new hydrocarbon level was 8 and the carbon monoxide level was .01 and that should get me by without having to buy a new cat.

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Report this Post07-14-2013 12:26 AM Click Here to See the Profile for armosSend a Private Message to armosEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by zmcdonal:
Got it to pass yesterday! Took it to the shop I use and they hooked it up to their fancy diagnostic machine that uses an exhaust probe to track emissions levels. Turns out my ignition timing was pretty off. He said it wasn't even close to the mark. He also said my cat was burnt out but that he thinks we can get it to pass without installing a new one.

With the 7730 computer you need to disconnect a wire by the distributor to put the ECM into base timing mode in order to set the timing. They told me to unplug that connector before the test and run it through and reconnect it afterwards. My new hydrocarbon level was 8 and the carbon monoxide level was .01 and that should get me by without having to buy a new cat.


Was it over-advanced before, or retarded?
If I understand correctly, you set the base timing to spec, but left that connector unplugged during those measurements? So those figures come from running the engine at a *total* advance of 10BTDC?
I've read of one other case where retarding the timing gave a measured improvement. Interesting to see some corroboration of this.

I had to retard my timing last time with a chip, not because of emissions levels, but because of a hunting idle (which is forbidden during the test). I had to retard it to fix the idle. The retard I used in the chip put the timing near where you are, and it's HC/CO levels were basically zero. I already had a new cat though so I didn't know what affect the timing really had on emissions. It's interesting to see you were able to get readings that low with a bad cat.
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Report this Post07-14-2013 03:29 PM Click Here to See the Profile for zmcdonalSend a Private Message to zmcdonalEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by armos:


Was it over-advanced before, or retarded?
If I understand correctly, you set the base timing to spec, but left that connector unplugged during those measurements? So those figures come from running the engine at a *total* advance of 10BTDC?
I've read of one other case where retarding the timing gave a measured improvement. Interesting to see some corroboration of this.



You know that's a good question, I was going to ask the mechanic that and totally spaced it out. Yes, he set the timing to spec and I left the connector unplugged during the test. It did set off the "check engine" light though, he told me they should still test it and it shouldn't matter that the light is on to them since the car is that old, and to tell them that it's a computer issue since the car is running with a different computer, and they should just have me sign a waiver that I know the light is on. I found it kind of odd, the other times I took the Fiero through testing they asked if it had any dash lights on (and it didn't), but the last time that I went though (with the light on) they didn't even ask me about lights being on.
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Report this Post07-15-2013 09:37 PM Click Here to See the Profile for armosSend a Private Message to armosEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by zmcdonal:


You know that's a good question, I was going to ask the mechanic that and totally spaced it out. Yes, he set the timing to spec and I left the connector unplugged during the test. It did set off the "check engine" light though, he told me they should still test it and it shouldn't matter that the light is on to them since the car is that old, and to tell them that it's a computer issue since the car is running with a different computer, and they should just have me sign a waiver that I know the light is on. I found it kind of odd, the other times I took the Fiero through testing they asked if it had any dash lights on (and it didn't), but the last time that I went though (with the light on) they didn't even ask me about lights being on.


Sounds like maybe your state has a rule about the lights but only for newer cars. I don't know though.
I don't know what means you have of reprogramming your ECM, but if you can, it might make the politics side of things easier if you put the retard in a chip that you can swap in for future test days. That way there won't be any check engine lights bothering anybody.
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zmcdonal
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Report this Post07-15-2013 10:16 PM Click Here to See the Profile for zmcdonalSend a Private Message to zmcdonalEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by armos:


Sounds like maybe your state has a rule about the lights but only for newer cars. I don't know though.
I don't know what means you have of reprogramming your ECM, but if you can, it might make the politics side of things easier if you put the retard in a chip that you can swap in for future test days. That way there won't be any check engine lights bothering anybody.


Yeah I was thinking in two years when it has to go through again I might just take off the back of the cluster and remove the bulb before I go and just sit the cluster piece back on there so it doesn't look suspicious. Just in case so I don't run into any problems.
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Report this Post07-15-2013 10:57 PM Click Here to See the Profile for cmechmannClick Here to Email cmechmannSend a Private Message to cmechmannEdit/Delete MessageReply w/QuoteDirect Link to This Post
Most states now won't test with a Service Engine or Check Engine light on.
Many states rely on OBDII standards to check for emissions. 1995 and later. Even if you remove the bulb they normally will check for any current or history codes stored.
ODB1, 1.5, 1994 and earlier most still use exhaust sample.
HCs are always unburnt fuel. Combustion chamber temp, timing, cooling system. Misfire fuel(too little), air(high O2), ignition.
HIgh COs without high HC partially burnt fuel. Anything that can cause it to run rich or too cold. Will have lower than normal O2 also.
Evenly elevated(not grossly)HC and CO Converter, but O2 should be near normal.
NOX most of the time, engine temp or EGR problem.
Grossly elevated HC and CO should have been able to find it without Gas Analyzer. ex. EGR stuck open, low vacuum, causing the ECM to make things pig out.
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Report this Post07-16-2013 03:12 AM Click Here to See the Profile for armosSend a Private Message to armosEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by zmcdonal:
Yeah I was thinking in two years when it has to go through again I might just take off the back of the cluster and remove the bulb before I go and just sit the cluster piece back on there so it doesn't look suspicious. Just in case so I don't run into any problems.

When you first turn on the key, the light is supposed to come on temporarily. If it doesn't do that they'll know the bulb is out. If they care about the light to begin with then that's probably something they will be expected to look for.
However, at least in CA they aren't expected to keep the equipment to scan for codes on anything that predates OBD-2. So if the light appears to work correctly, and isn't on during the test, then they're satisfied.
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