Emissions

[Macamon]

I have a 92 Vert, I've posted about it a couple times already. It was running just a little rough, the exhaust is really smelling rancid poor mileage, soot on body around tail pipe.

I had a mechanic go through it, he said he found several things wrong with it but still didn't have the problem nailed. His last words were: "put a thermostat in it and it should run better once it is up to operating temp" He told me to put in a 192deg which does not exist (I'm really beginning to wonder about this mechanic but he was highly recomended by a friend) I put in the 170 that the book calls for but it is still running rich and rancid

Any ideas??

[[s3]]

Check for codes, and get a tune up, 02 sensors might be fried, amongst other things.

[DAEDALUS]

El Segundo...hope you didnt' go to BMC! They are terrible.

Yes O2 could be bad.Also, bad coolant temp sensor/connection is commonBad MAF connectionBad injector or bad injector seal

Pull the spark plugs and look at them--they might tell you if all cylinders are rich or just 1 or 2.

[Macamon]

Tune up was done before turning it over to the mechanic 02 sensor was changed two days before finally giving in to taking it to mechanic (what other things)

]Check for codes, and get a tune up, 02 sensors might be fried, amongst other things.

[Macamon]

Mechanic was finish line automotive, I finally took it to him after a fruitless request for referral here on nicoCoolant temp sensor was replaced by mech and all connections have been basted with dielectric grease. Injectors were pulled, and cleaned with fresh seals and a new thermostat was installed (tested at 170 deg)Thanks for the heads up on BMC

Help!

[illreaxion]

Sounds like your t/stat is opening fine...one of your injectors could be leaky...run a higher temp thermostat....hmm...hows your fuel pump/relay? Id check those 2, since youre saying its rich...engine probably isnt warming up high enough to be efficient. hows your cat? it could be clogged/old too.

[DAEDALUS]

I really wish I could help you out. Sounds like an interesting afternoon's worth of work.

You had a tune-up done--did you take a look at the plugs? (assumed they were replaced).

As far as shops, Z-expert has a very good reputation, but I don't know if he has a Consult.Jim & Jacks...heard both good and bad things from different people, so the jury's out on that one.Heard of finish line, but don't know about their reputation.From Infiniti General:

Arrow AutomotiveRosecrans Blvd. near LAX, L.A., CA310-973-9785Jeff Morrow, shop owner, former builder on early 90's 300z GT race car (red/white/blue Stillen car). Prideful, dedicated, by the book guy.IIRC, he's like 65 an hour, and is cool with you bringing in parts you get from Everything Infiniti.

Everything Infiniti = http://www.everythingnissan.comYou'll save a lot on whatever parts you need.

The method of troubleshooting this is to first figure out if it's rich on some cylinders or all. If some, then it's not the ECU or the MAF or the coolant temp sensor. If it's all cylinders, then it's not a single leaking injector or seal. Once you narrow that down, you start troubleshooting the remaining candidates. There are tests you can run for each possibility...but easiest is with a Consult. Why dealerships can charge $100/hour (but they still prefer to replace parts without proper diagnosis sometimes). You've had things replaced/reinstalled, but that's just circumstantial evidence. Doesn't tell you what the car thinks it knows, why it's acting up.

Question I should have asked sooner: How long are your drives? Do you know if the O2 sensor is heated? Non-heated O2 sensors take a long time to heat up, so car runs rich till they start working. Folks who only drive short distances get poor gas mileage compared to those who have long commutes. Not much you can do about running rich when the engine's cold.

[Macamon]

Man, for my last 5 posts on nico I think this is the most valuable return I've had yet!

Illreaxion:T/stat is ok, however the car is beginning to have overheat problems (whole new can of worms for me but I know how to deal with this)

Ron at Finish Line said he cleaned the MAF and pulled all the injectors, He changed the plugs just for good measure and said nothing of wet pluggs. He did mention the computer wanting about 192 deg but all books call for a 170 which is what I'm running. Cat is only 6 mos old and is an aftermarket highflow model. Fuel pump relay will need a look, I haven't done that yet.

Daedalus:I wish I got Arrow's information a month ago, I probably wouldn't be worrying about this right now. I kindof have the feeling that Ron is poking guesses and hoping to eliminate the problem by process of elimination. If I don't get the problem resolved with the input you have given me I will run the car over to Arrow. As for Jim and Jacks STAY AWAY!!! I've heard many horror stories about the facility, the most immediate of which was a truck repair they tried to hand off to the owner unfinished (didn't even bolt the camper shell back on correcly) After they got that fixed he took it out and his transmission locked up. Their reply "It's not our fault"

My drives are generally 20-100 miles, the O2 sensor I'm running is the standard bosch replacement. Even after 30 miles or so I'm still pumping noxious fumes from the pipe

Thanks guys!!!