[Primevci]

I tried to DEQ my 1989 caprice yesterday and it passed on everything except the nox i need to score 3.70 or under and i scored a 4.25, now i checked my egr valve py pressing in the diafram and the engine started to choke on itself so from what i read the valve is fine, now i was wondering could my NOX be to high because my engine is running to hot? I have the a 350 5.7 TBI in it also and not sure what kind of thermostat but i couldn't get the engine to heat it up to pump water threw it so im thinking there may be a high degree thermostat what should i place in there if this could be the problem? or what way could i test the thermostat? or what do u guys recommend....

 

[NXS]

We don't have standardized smog controls here but let's see what we can do.

You may be correct about the temp being too hot.

Like you said> a cooler thermostat

Also, is that carb or tbi?

A lean idle mixture can also cause this problem.

 

[Siggy_Freud]

Isn't the NOX count mainly what the cat converter controls? Id be looking into pricing one of those.

 

[packratwrecker]

I'd vote against the cooler stat, if it has the correct on in it now.
Those computers on fuelie motors are designed to work with a 195 degree thermostat. Putting in a cooler one might confuse the computer, and drop a trouble code. Putting in a new stat may fix the problem, if the one you have isn't responding correctly.
My 91 chevy pickup will trip the check engine light occasionally on a cold day, unless I have a load on it. I put a 180 in when I changed the water pump.
Something else. It may be hanging up on the stat gasket, or somebody may have been a little overzealous with silicone, when they put in the last one. A little gob a silicone, or a gasket, brushing against the stat lip could cause it to hang up, until it builds enough pressure to pop past it.

 

[Ghetto Jet]

Cat. My mom's caprice failed for nox. I put a new cat on and it passed.

 

[NXS]

Catalytic converter...we don't have those either!

 

[Primevci]

Damn i was hopign it was not a cat sicne the rest of the test passed "hydro carbin" wonder how much those cost unfornaly im on a very limited budget... laid off and not much on uneployment is there any type of test to check the cat.? oh yea its also TBI not a carb.

 

[NXS]

What were your hydrocaron results? And what is the passing limit?

 

[spinn]

forget the cat for now. the main common reasons for high nox is carbon buildup, then over advanced timming,then poor oil control/low oil, then cooling /plugged radiator(increase temperatures),then egr, then low octane fuels, thenwrong spark plug heat range, thenlow fuel psi/poor pump,then finally i would check the cat.

HC limit is usually 220 ppm

 

[Primevci]

THC was 1.88 max is 2.00

here are the other scores

Nox 4.25 max 3.70

CO 11.2 max 32.0

co2 n/a

Nosie and smoke passed

 

[spinn]

if the co is pasing i think the cat is working

the engine has to be at the proper temp, sounds like thats your problem

 

[Primevci]

forget the cat for now. the main common reasons for high nox is carbon buildup, then over advanced timming,then poor oil control/low oil, then cooling /plugged radiator,then egr, then low octane fuels, thenwrong spark plug heat range, thenlow fuel psi/poor pump,then finally i would check the cat.

HCis usually 220 ppm

OK i i did replace all the spark plugs, and wires about 3 months ago so those should be good, oil looked OK but was a little dark but didn't smell burnt, egr is fine as i put pressure on the diafram and it choked out my car, Low octane i run regular in it should i get some octane boost? Spark plugs i did get where what was recommended for my car at Baxter auto parts Fuel pump was replaced about 1 year "napa" or less ago

Temp would be a nice great cheap fix so what kidna thermostat should i put in there? or hwo should i test the one i have.....

 

[spinn]

180 is a good standard. yours is probably not closing ,staying open,and not building up its heat.

you can see if it is closed when cool. then boil it in water on a stove and see if it opens. have a thermometer ready to check the opening temp

lol ,watch those THC levels. dont want to come up trace

 

[Primevci]

180 is a good standard. yours is probably not closing ,staying open,and not building up its heat.

you can see if it is closed when cool. then boil it in water on a stove and see if it opens. have a thermometer ready to check the opening temp

lol ,watch those THC levels. dont want to come up trace

hehe.. i hate being on unemployment or i would sut taker this thing in if i miss diagnose it i could be in trouble.... I know its stuck close if anything cause i had my friend rev it at for about 10 minutes and no water ever went threw the top hose.... the one that leads from the Radiotor to the Thermostat on the intake manifold... sorry im nto to tech savvy with cars so dotn shoot me if i screw up the names of what thigns are...

 

[Primevci]

i jsut did the thermostat test it dosent start openign till abotu 192 ill probly just get another one to be safe i pushed it with myhands a few times and it seemed really sticky..... i dunno what do u guys think..

 

[spinn]

there is a wax pellet against a spring ,that melts at a temp ,to open the t stat. this pellet can get damaged by overheating, the above mentioned silicon bead can also interfer.

you should get a new theromstat. they are cheap, upgrade to a bypass style they seem to last longer.

 

[Primevci]

whats a bypass style?

 

[blazinwest]

i say screw those hippys. take off your cat and egr

 

[Primevci]

well yea except i would neevr pass deq.... and a 400 dollor expired tag ticket dotn appeal to me to much..

 

[NXS]

How is your timing? It may need to be advanced. Does it crank over really easy then kick or does it pop right off?