<U>Cut me some slack, I'm new to this.</U>
91 Civic DX Hatchback, 1500, no mods, new head, water pump, timing belt, O2, original Cat. Here's the short version.
Trouble with gas pedal feel when car is running, smooth when car is off. Believe there was a TSB regarding this. Car hesitates from a stop. Maybe someone has access to TSBs?
Failed emissions (Nox) but HC is also high. (Snorkel was off during test. Will put it back on for the next Test)
HC 0.67 Limit- 0.8 Pass 162 % higher
CO 5.48 Limit 15.0 Pass 3.2 % higher
Nox 2.8 Limit 2.0 Fail 124% higher
Overall 2% Lean
Graph shows sharp spikes which look like they coincide with pedal movement and/or shifting. 0 to 29 MPH (All emissions spike similarly)
These spikes are of very short duration, but very high which makes the average ppm look really bad.
30 to 55 MPH levels are near normal.
Car runs great otherwise, good power, good MPG.
Can't be sure the timing belt install is 100% correct. Can't get the marks to line up without over tensioning the belt. Guessing I'm not doing it right. Maybe someone can help with this. Chilton's says there are different reference points for the cam and crank pulley marks, depending on a 1500 or 1600. Well hopefully someone can help with this. Thank in advance.

 

try some kinda of clearner you didn't fail by much from what I have red.

maybe carbon cleaner that should work make sure your car is warmed up.

 

high nox is due to low internal engine temp. if temp in cylinder is under 2500 deg. f. during combustion the car will almost never pass so keep it warm!!! as far as your throttle response and power spikes these are problems most likely connected to the high HC levels check brake booster diaphram for leakage if power brakes. Also check for unconnected vacuum lines on the intake manifold or the intake manifold gasket itself. actually every thing i just said is summed up with "warm up the car and plug all vacuum you cannot find proper fittings for and you'll be fine.
and Good Luck!-ryan

 

Yea, I want to try the Seafoam stuff and see if that helps, but I am still running rich when the spikes show up on the emissions test. Thing is, I get two more free tests then I have to pay. Just want to do as much as possible before each one. Could being carboned up cause me to run rich? What I might need is an OEM service manual. My Chilton's is pretty good but sometimes generic because they cover so many vehicles.
Thanks for the response,
Paulie, Milwaukee WI

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Koup &raquo;</TD></TR><TR><TD CLASS="quote">high nox is due to low internal engine temp. if temp in cylinder is under 2500 deg. f. during combustion the car will almost never pass so keep it warm!!! as far as your throttle response and power spikes these are problems most likely connected to the high HC levels check brake booster diaphram for leakage if power brakes. Also check for unconnected vacuum lines on the intake manifold or the intake manifold gasket itself. actually every thing i just said is summed up with "warm up the car and plug all vacuum you cannot find proper fittings for and you'll be fine.
and Good Luck!-ryan </TD></TR></TABLE>

lol is caused by high internal engine temp. gets ur facts straight.
its so high that gas an fuel ignite

make sure your cooling system is working radiator fan themo stat. like I said try some cleaning soloution that should solve your problems. High nox is not caused by low internal engine temp

 

It seems to me the car is running cool cause the radiator doesn't get all that hot, not like when it was new anyway. ( new 195 F. T-stat ) Which might lead me to believe the timing belt is not on quite right. As far as the vacuum stuff goes, I want to put a gauge on it and see if it bounces around. Maybe pinch off a line here and there, like to the brake booster. Do you know how many in. wc. is normal for my engine? Thanks for your help.
Paulie, Milwaukee, WI

 

its most likely carbon build up. please just try sea foam it takes like 10 minutes to do. then u can poor the rest in the crank case and gas to clean injectors.

and fyi its a terrible idea to have a 195 * thermostat on an aluminum motor.

 

Since when have they been doing smog **** in wisconny?

 

I am definitely going to use the sea foam, but if I still have a problem with the lurching after I'm done, not sure what I'm going to do. But your right I've heard some amazing stories about sea foam.
As far as the 195 T-stat. My car runs so cool, I have to use it to get decent heat. Now I bought my wife a 97 Accord wagon and it heats up, gets good and hot, much hotter than my civic and passes emissions no problem. I can put my hand on the radiator cap, hold it there and not get burned. No way with my wifes Accord. But yes I will use the sea foam. Sorry I tend to ramble....
Thanks again,
Paulie

 

thermostat may be stuck open.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bossman032 &raquo;</TD></TR><TR><TD CLASS="quote">make sure your car is <u>warmed up</u>.</TD></TR></TABLE>


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bossman032 &raquo;</TD></TR><TR><TD CLASS="quote">lol is caused by <u>high internal engine temp</u>. gets ur facts straight.
its so high that gas an fuel ignite

make sure your cooling system is working radiator fan themo stat. like I said try some cleaning soloution that should solve your problems. High nox is <u>not</u> caused by low internal engine temp</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by akashelby &raquo;</TD></TR><TR><TD CLASS="quote"> As far as the 195 T-stat. My car <u>runs so cool</u>, I have to use it to get decent heat. </TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bossman032 &raquo;</TD></TR><TR><TD CLASS="quote">gets ur facts straight.
</TD></TR></TABLE>

? I'm Confused, <u> gets ur facts straight?</u>

 

I pretty much had the same problem with Stitch, er...that's my blue '91 Civie's name, anyway, I started using BP (midgrade) gasoline, used some industrial strength injection cleaner, and switched out the spark plugs, and it actually leveled out.

Best o' luck with that.

 

I had my smog check last week but it didn’t even get me a result. They told me the same thing that my timing belt was wrong and I needed to get a brand name air intake. The test started but in the middle, it just stopped?? So I am working with my brother to install a new timing belt and change the antifreeze. BTW what is sea foam? Does that help pass the smog? If so where can I purchase it?

 

Well it sounds like at least some of us are getting our cars in order, the guy with the 91 Civic named Stitch. That's his car's name. Congradulations man. As far as my car goes. Nobody told me I <U>had</U> timing belt issues. I only suspect it because I put a new belt on the car and I am far from an expert. Now there are some people who leave replies in these forums who really sound like they know what they're taking about. I'm sure somewhere in the middle lies the truth,, ha ha. Anyway my strength is heating and air conditioning. I do that pretty well but everynow and then I get humbled. Any good tech does wouldn't you think? So what am I getting at? Well I try to take a logical approach to troubleshooting anything I work on. Part of my logic is to stay humble and continue to learn. The principles of refrigeration and combustion are right in there with cars. It's not rocket science. For instance the first couple of cars I looked at with emissions, saw lots of wires and sensors, some I could tell right off what they were. Like a crank sensor for instance, an easy one. A coil that's mounted stationary and hunks of metal fly by it. I saw those back in 1980 on mainframe printers. You put a scope to the output of the coil, and every time that hunk of metal flies by, it throws a pulse. How about the Temp sensor? Car has to know when it's warm so it can change the mixture. It's magic, no more choke. Now there is an optimum mixture of gas and air, a.. the stoichiometric something or other. 14.7 to 1 rings a bell. Same thing with what I do with heating. Oil furnaces, very fussy about the mixture if you want to achieve the 80% plus efficiency.
Well I went to the emissions place and failed Nox, my HC was high but passed. So I'm thinking well high HC,,, da... hydrocarbons, isn't gasoline like almost all HC? This car has never had high HC. I spilled some High C in the console once but never high HC. Must mean I'm not burning all my gas. But why? Right now I have to make sure all the mechanical **** in my car is set up right before I start replacing emissions stuff. I need to know that my valves are opening and closing at the optimum time to burn all that gas and air. And my car is not running as hot as it did when it was newer and passed emissions. My valve timing has to be dead on before I go forward and replace emissions **** and return to the test center. That's where experience comes in. I'm not a motor guy and I don't understand a lot of the terminology but I'm willing to learn. So, does anybody out there know why I am having such a hard time with the timing belt? If you put the crank at TDC of the compression stroke shouldn't both of the valves be closed? Well the belt won't alow me to maintain that position because of the teeth. If I really crank up the pressure on the belt with the tensioner, the marks line up. The car runs good and hot but to tight for the water pump and it wears out the bushings in no time. So, would someone be kind enough to give me a hand with this. I sure would appreciate it. If any of you need help with your heating or A/C I'll do what I can.
( Gotta get a civic si ! )

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by akashelby &raquo;</TD></TR><TR><TD CLASS="quote">So, does anybody out there know why I am having such a hard time with the timing belt? If you put the crank at TDC of the compression stroke shouldn't both of the valves be closed? Well the belt won't alow me to maintain that position because of the teeth. If I really crank up the pressure on the belt with the tensioner, the marks line up. The car runs good and hot but to tight for the water pump and it wears out the bushings in no time. So, would someone be kind enough to give me a hand with this. </TD></TR></TABLE>I thought I'd pick this out because many might not read your whole post.

Is it possible you might have the wrong timing belt on there?

 

****!!! I failed smog check today!!!

 

Appreciate the response, but the belt is the right one. I matched it up with the old belt tooth for tooth. Even put the old one back on, same story.

 

Hey Formula sorry to hear the bad news man. That's why I want to be sure about a few things before I return for another test. So did you and your brother replace your timing belt? Let me know, Thanks.