Well, the Mustang failed emissions today:
HC: 242PPM to a 220PPM max
CO: 0.34% to a 1.20% max
I am thinking some fricken sensor somewhere, I was thinking TPS (throttle position sensor) but wanted to hear your input. The O2 sensor and the cat are relatively new, as is the tune up (all about 20k I think, give or take a few thousand) Everything else is bone stock original with 95k on it, including the T-belt. It will occasionally stumble then stall out. I know little about EFI, and kept cussing on the way home from the DMV that if it was a carb 2.3 I would've swung around the corner, whipped out a screwdriver, tweaked it and drove back in to pass. IMO, 242 thru a nearly new cat is horrendous. My 69 F100 with a 390 4bbl, WITHOUT a cat wasn't that dirty.
Reason I am thinking TPS is because it seems to stumble only when I let off of the pedal back to idle. Am I correct in thinking the TPS is the little black piece shaped sorta like a diamond with the corners rounded off that is mounted directly on the back (firewall side) of the upper manifold? Or is it the long cylindrical thing mounted in it's own bracket a bit higher than the diamond thing. GEEZ I sound like an idiot not knowing w.t.f. is what. I guess it is about time I joined this millennium and it's new fangled technology seeing as we are already almost 9 years into it. Ok, enough venting. I am so glad to be a member of this group. Somebody help me get my sheep in wolf's clothing running right and able to be registered again. It's either that, or a ten mile bike ride to work and another one back.
Thank you all!
--Doug
Near the tps there should be another electrical item that controls idle air I would go for that 1st and the map sensor clean both well with the carb spray. I dont know that year eng. nor do I have manual on it. Fred :)
Quote from: douglasskemp on September 26, 2008, 07:56:56 AM
TPS is the little black piece shaped sorta like a diamond with the corners rounded off that is mounted directly on the back (firewall side) of the upper manifold?
This is correct. you can test this with a good digital meter while the key is on and engine off. Here's a good article http://www.allfordmustangs.com/forums/2-3l-tech/77978-1984-mustang-2-3-turbo.html (http://www.allfordmustangs.com/forums/2-3l-tech/77978-1984-mustang-2-3-turbo.html)
Quote from: douglasskemp on September 26, 2008, 07:56:56 AM
Or is it the long cylindrical thing mounted in it's own bracket a bit higher than the diamond thing.
Thank you all!
--Doug
This is the idle air control valve.
The idle air control valve does control your idle speed and may be a contributing factor to your stall problems BUT, it will not increase emissions unless the car is idling too slow. Freds right about cleaning this part out but only the carboned up valve part It will do nothing to correct any internal electrical issue. Try to pull codes if possible.
Check to see if your EGR valve and base is clean,and if it's working.....
**UPDATE**
Took it in today, and she passed.
HC: 89 PPM to a 220PPM max
CO: 0.00% to a 1.20% max
I was right, well as far as it being a sensor of some sort. I wrote my dad too, and he said with HC being that high it would be his thought to check the O2 or the cat. Well with the O2 sensor being a heck of a lot cheaper than a new cat, I decided to give it a shot. Went to remove it, and it was loose! Which is just another argument to do your own work on your cars. Took it out and got a new one. It seems that one of the better ideas they have on this car is where it is placed in the manifold. It is in such a spot that an open end wrench does not have enough room to get a good bite on it. ALSO, the sensor connector has a little piece of plastic formed in a 'loop' to keep the connector release from being easily pressed. This makes the connector slightly larger than the inside of the 5/8" wrench you need to remove/replace it. Easy fix, remove that stupid loop with a nice pair of pliers. TADA! Now you can tighten the O2 sensor until you think it'll break, and then tighten it just a little more for good measure.
That's all I did.
Thank you to all of you that gave me things to try, I am sure I will need this info later, and some of it I will just end up doing (like cleaning parts of grime) just to keep it running as long as I can.
--Doug