Silver MTX Fails AZ Emissions twice

[Jim Ellis]

Can't seem to get my 95 MTX to pass emissions.

AZ spec for NOx 2.00gpm car has scored 5.00gpm twice.
AZ spec for HC is 0.8gpm car has scored 1.8 and today 2.51

Situation: 13K on a NESS level 3 60K new O2 sensors clean good stock MAF, new air filter, new fuel filter, removed the TedB chip, high flow catless Y-pipe installed. Using a stethescope sounds like cam chain tensioners are worn, difinitly hear some chain slap. The engine is running rich, getting 18mpg driving like an old man. Car pulls good all the way across the tac, no apparent miss firing.

Could the worn tensioners be affecting the timing enough to cause the bad mileage and poor detnation?

I got to get this baby passed and I can't believe as clean as a SHO engine runs that I am so far out just due to the lack of Cats.

Thanks for any help and suggestions. Anybody got a set of tensioners they want to sell.

 

[RStalveyARFF]

I just scored a .75 on NOx with the 3.2 and all mods still installed, finished with a catless y-pipe. I'm thinking your problem might lie in a vacuum leak.

 

[yamahaSHO]

Is the car running warm?

 

[AutoSHO]

I'll continue Jason's thought and say this: Replacing the ECT often leads to better fuel economy and the car will turn the fan on at the proper temperatures.

Any other unusual driveability problems?

 

[Off Road SHO]

I checked Jim's car last night with an infrared gauge and the thermostat is opening at 180 degrees. He does have some pretty loud tensioner slap, but I can't see where that would change the timing so much that he would get very poor mileage and super high HC readings.

I listened for vacuum leaks but didn't hear any at all, and nothing else jumped out as the cause of the problems. I should have checked timing while he had it there I suppose.

Tom

 

[Jim Ellis]

It seems to be running okay with exception of the gas mileage. All the fluids are fine, no oil use, no smoke, idles smooth, no apparent miss firing, runs warm and fan cycles normally.

My temporary registration expires tomorrow so I got to go plead for an exstension, no waviers on cars that are more than twice the spec.

shrug I'm stumped, it's headed for the shop.

 

[Chris Benvie]

I miss it. I wish the best for it Jim, i really don't get what it is. I even thought injectors or something, but those are pretty recent. I don't quite get what the deal is with it. Hopefully the shop will be able to figure it out, its prolly something as simple as a sensor.

What is this cam chain tick you are talking about?

 

[yamahaSHO]

When an ECT goes bad, the computer gives the motor more gas in efforts to warm it up like with a cold start... It thinks the motor is colder than it actually is. Even if the T-stat is opening at the right temp, the motor will still run warm... In fact, if you run with the radiator cap off, your coolant may boil.

This will cause the motor to be warmer than normal, worse gas milage, and delayed turn on of the fan. I had this problem when I bought my car... changed the ECT and the fan turned on when it was supposed to, and my tailpipes stopped accuring more soot.

 

[Chris Benvie]

yamahaSHO:
When an ECT goes bad, the computer gives the motor more gas in efforts to warm it up like with a cold start... It thinks the motor is colder than it actually is. Even if the T-stat is opening at the right temp, the motor will still run warm... In fact, if you run with the radiator cap off, your coolant may boil.

This will cause the motor to be warmer than normal, worse gas milage, and delayed turn on of the fan. I had this problem when I bought my car... changed the ECT and the fan turned on when it was supposed to, and my tailpipes stopped accuring more soot.

Ok now this would make sense, i noticed that when i would clean the tailpipes there was a bit of soot, not bad but a lil. I figured this was due to the catless Y-pipe. That would also explain the sometimes late turn-on of the fan.

Jim i think this is the problem. Wish i thought of that before. Woulda made things easier.

Thanks Jason

Edit: that ECT is I believe under $20 at your local parts store. Also, you may find more power in the car if this is replaced. God the thing ran like a ***** ape as it was, i can only imagine now. hail

<small>[ March 26, 2004, 12:27 AM: Message edited by: Chris Benvie ]</small>

 

[yamahaSHO]

Yes, you can pick these sensors up at Auto Zone for about $16 or so.

The ECT is located just aft of the T-stat... I am sure Tom knows where it is.

I am actually pulling the Auto Zone one out of my car and putting a new Ford one in... The AZ one is still pretty new, 10k miles... but since I have a brand new Ford sensor, I want to use it.

 

[Jim Ellis]

Thanks guys, I'll let you know what shakes out. I'll give the ECT a look too.

 

[yamahaSHO]

Jim Ellis:
Thanks guys, I'll let you know what shakes out. I'll give the ECT a look too.

Before you take it to a shop, I would personally just replace the ECT... Not many shops know much about the SHO and the will charge you for their own learning.

 

[SMD69]

HMM well just wondering here. Jim you said you has a Ness 60k done. So it was in Mass at one point.
If your in AZ now would the altitude of where you are be a factor in the way it is running.
I remember that when I was stationed in AZ. I drove my car from Mass to AZ and it ran rich also but work on the carb and a new thermastat fixed it seeing it was set for a cooler climat when I had it in Mass.

 

[Jim Ellis]

The SHO fuel injection system when working correctly automatically corrects for all those atmospheric conditions. I think it is a dregradation in the ECT. It is now starting to run rough during warm up.

As I get older my ego gets easier to go around. It's in the shop. They learned SHO on my 90 MTX. I am fortunate to have a good one I trust.

 

[Slo-Sho]

If you're really in a pinch to get the inspection pull the SPOUT connector and re-test. This will revert the ignition timing to 10* BTC...your car will run like ****, but it will increase the likelyhood of it passing.

 

[Chris Benvie]

I have already consulted him on this procdure.

 

[sdpatt]

High HC means unburned fuel. How old are the spark plugs and wires? What type of plugs are in there and what are they gapped?

 

[Chris Benvie]

Level 3 60k was preformed at 120k the plugs and wires have MAYBE 14k on them now.

Not sure what they are gapped at.

Scott this is my old car.

 

[sdpatt]

What plugs were used and what are they gapped to?

 

[Chris Benvie]

Motorcraft plugs and wires.


I don't know what they were gapped at, like i said before.

I could ask fred as he did the 60k.