failed emissions please help

[1995 gst]

I failed emissions due to high co readings, it said it is from unburned fuel. before i did emissions i replaced the plugs and wires and gapped accordingly. if its not that what elts could it be?

 

[Talondvr]

Boost leak test would be first on my list.

 

[laserspeeddemon]

Lack of air, lack of spark or excessive of fuel could be your problem.

As stated above check for boost leaks. Make sure the filter is new/clean. Gap plugs to 0.28" and make sure that the car isn't "stuttering". Make sure your fuel injectors are clean so that a injector is stuck open. Ensure that your MAF and ECU are in good working order. A file of the MAF puts the car into closed loop, which means fuel is dumped in based on a fuel not by counting the air. Also ensure your cat is in good working order.

 

[GSLENK]

since you are all stock.... Might want to double check you cat converter, make sure the catalyst is all in there. Think about what causes escess fuel, maybe an injector not firing, or maybe metered air is escaping after MAF, and the AFR is rich, since fuel doesnt escape, but air does, like Talondvr said. MAybe you could scan your emmisions report or post up numbers...

Also, in my state, $300 on equipment that *could* effect emissions "buys" me a 2 year waiver. so time for that turbo upgrade or ecmlink, intake, exhaust whatever you want Just make sure you have a receipt.

And remember to warm your car up plenty before they put the sniffer on. dont just cold start and go there. get it nice and hot first. did the PO put a colder rated thermostat? are you sure you are out of open loop?

 

[1995 gst]

the cat is good its only 6 months old. and in my state the minimum is 750 dollars before i get a ONE year wavier. i had it taken to an emissions repair station and its gonna cost 150 dollars to diagnose and who knows how much to repair.

 

[bcjjones]

Post the standard PPM for the CO and what your car actually read. Might have some suggestions based off the numbers

 

[DSM1G90]

High CO mainly means that the O2 sensor is super tired and it's not telling the ECU to meter the fuel correctly, and a tired 02 sensor will not trip a CEL

... and check timing, plug gap, vacuum leaks, do an oil change, get the thing super hot before a sniff test .. et.al.

I had the same problem along with high HC with my first sniff test - tired o2 sensor along with other factors that I had to fix prior to my next sniff test... but did pass the 2nd one with flying colors after all the things that I posted above were completed.


Amazing how dirty oil can fubar a good emission test.

Idaho (just in two counties that do the sniff test), we are granted 200 bucks to fix.

 

[1995 gst]

ill post the reading when i get the paper back. its currently at the emissions repair shop diagnosing the problem. and i wish i lived in a state that was that low. its 750 dollars here. before i get an auto one year pass.

 

[Black-Out]

Make sure your absolutely all stock because I've come across a few cars that were put back to stock but the wally 255 was never removed and the factory fuel pump re-installed which can cause you headaches in the unburned Hydrocarbon area. also make sure your air filter is good and clean your exhaust has no restrictions and your compression is good and even as low compression will cause problems with both C.O and H.C.'s ......

This is ironic for me, cause I been having issues with my car not setting readiness monitors at all, which in my area older cars (anything made between 95-97) just go strait to a 2 speed idle smog test on the computer but because my car is a 98, the computer wants my car to show all but 1 monitor ready in the log screen. I think the p.o. may have swapped ECU's on me and left me in a perpetual state of I'm screwed ...... I need to pull my ecu and check into it.

William-

 

[1995 gst]

my compression is 30-40psi on each cyl

 

[Chrispy0530]

30-40 PSI after a compression check? You're doing something wrong, that's ridiculously low. Make sure the car is fully warmed up, and the throttle is wide open when doing the tests.

 

[Black-Out]

^^^^^What he said...you should at least see around 150 or so psi and you need to make sure you crank for 10seconds with the throttle being held to the floor for the full 10sec cranking to get an accurate reading. Again if those numbers are low across the board or the compression from cylinder to cylinder is more than 10% off you have some issues there that will need some looking into.

William-

 

[1995 gst]

did another compression test and it was still that low. cyl 1 was at 47 psi cyl 2 was 33 psi cyl 3 was 19 psi and cyl 4 was 61 psi.

I did the test twice to make sure and cranked open for around 10 seconds like said,

 

[DSM1G90]

Make sure the car is fully warmed up, and the throttle is wide open when doing the tests.

and the MPI fuse removed. Otherwise, you're adding fuel to the bores which will make the readings incorrect.

Are you "locking" the needle down after each test? Do you have a threaded tester, or one of them rubber nosed varieties.

Rubber nosed variety - one needs to hold that one down tight against the head so no gas will bleed out, but the threaded one should have a button on the side to lock down the needle when the needle is at the highest..

Motor can't run under them low readings.... It should have, at least 120lbs per test to be legit

 

[1995 gst]

i used the compresser on a different dsm and they hit around 119 per cyl give or take 10 give or minus, so it must be my vehicle. the tester i bough at an autoshop for around 80 bucks bran new in package.

the other dsm was a 2g though, so the psi will be a little higher anyway,

 

[Black-Out]

Time for a leak down test to see if you have stuck or bent valves....I highly doubt the bottom end is shot but I could see a valvetrain issue causing such dismal readings....But as mentioned earlier by DSM1G90 The car shouldn't really run- or at least run half smoothly with numbers that low.....check for valvetrain issues with a leak down then post up your numbers. If you hear any hissing in the exhaust or intake when you do the leak down at TDC then you'll know you have some issues that'll require some investment...

William-

 

[DSM1G90]

..wonder if he has cam timing issues if his compression is that low - which is easy to check out:

Take the cam sprocket cover off and roll the pulley to TDC to see if cam marks align up.

 

[1995 gst]

ok the emissions repair shop said no leaks and have no idea what it can be so they dissmissed me no charge.

The emissions numbers which you guys asked are.

HC gpm. 5.2988. limit 1.500 = fail

co gpm 12.3558. limit 15.000 pass

co2 416.7321

nox gpm. 4.0448. limit 3.500 = fail.

no dashboard lights = pass

catalytic cvonverter pass

o2 sensor pass.

 

[Black-Out]

ok the emissions repair shop said no leaks and have no idea what it can be so they dissmissed me no charge.

The emissions numbers which you guys asked are.

HC gpm. 5.2988. limit 1.500 = fail

co gpm 12.3558. limit 15.000 pass

co2 416.7321

nox gpm. 4.0448. limit 3.500 = fail.

no dashboard lights = pass

catalytic cvonverter pass

o2 sensor pass.

Wow that HC reading is STOOOOPID high........You either have some serious injector leaks , incomplete combustion (which can be caused by poor cam timing,poor compression,weak spark energy or retarded ignition timing, or an untuned upgraded fuel system.....all of which are capable knocking the HC's way out of spec.

You may need to start at the basics and check cam timing like DSM1G90 has already suggested then re-check compression and leak down numbers also check the injectors which are easy to get to. Pull the rail and have them pressure check the injectors and spray pattern or maybe swap them out with another car. either way a leaking injector is not out of the question on a 16yr-old DSM and could easily screw up your chances of a passing grade at the smog test. Did you ever do a leak down test?

William-

 

[1995 gst]

no leaks. all tune up is complete. fuel system was cleaned. stock injectors stock pump. stock everything.

 

[GSLENK]

the cat is good its only 6 months old. and in my state the minimum is 750 dollars before i get a ONE year wavier. i had it taken to an emissions repair station and its gonna cost 150 dollars to diagnose and who knows how much to repair.

That evo 16g will almost get you there and that FP green will totally get you there. you should start planning your upgrade path to spend 750 a year for the next few years

Ok im done being a jackass.

Does CO do the whole historic tags deal?

seems like your state is 2x as strict as mine... but heres a shot, my car being a 1992 will turn 20 years old in about 2 months. it is also a discontinued line (thank baby jesus it isnt a gsx, no hate, just think, 5 more years if it was...)
that means historic tags, with no emissions/inspections.

I gutted all my emissions stuff, but ill wait till mid 2013 when my reg and emissions expire to register a historic.

PS:

What your mileage like (miles on car)?
for the comparison, mine has 25k at emissions time, all foctory provisions, minor minor MINOR boost leak at the factory TB shaft seals, (later to be confirmed to be the ONLY leak after i fixed it) I tested:
9ppm HC
.01 % CO
~15% CO2