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coreydmc
04-04-2012, 09:11 PM
Hey guys.. i have owned my delorean for about 15 years. I have always had a strong smelling exhaust. it is not a rotten egg smell. the smell is so strong if you are behind the car at all you will end up smelling like exhaust fumes until you change clothes. will changing my cat and 02 sensor fix this? it is starting to bother me that i dont even want to drive it anymore

Michael
04-04-2012, 09:18 PM
It could he that you are running very rich. An exhaust leak would also cause this as the vapors would build up in the engine compartment and work their way into the cabin.

PS. I assumed that the smell was getting in the cabin?

jawn101
04-04-2012, 09:33 PM
My $0.02: Go do your mixture adjustment first. Check the fuel system for leaks. Make sure the sender is sealing properly at the tank. Make sure the pump boot isn't full of gas and is sealing properly. If doing all that doesn't eliminate the smell, then come back to this thread :)

coreydmc
04-04-2012, 09:37 PM
thanks guys. what is the process for adjusting the mixture? also its hard to describe smell. its a heavy exhaust fume smell. not so much a gasoline fuel smell. my gas tank was rebuilt by pj grady a few years ago. is this a rich running smell? should i get a dwell meter?

jawn101
04-04-2012, 09:40 PM
I told you the whole process in your other thread....

http://dmctalk.org/showthread.php?3532-How-do-I-know-if-I-need-a-new-catalytic-converter&p=49980&viewfull=1#post49980

Yes, you need a dwell meter if you're going to tackle it.

coreydmc
04-04-2012, 09:42 PM
ok. thanks jawn. ill go to harbor frieght and get a dwell meter. is there any type i should get?

jawn101
04-04-2012, 09:44 PM
ok. thanks jawn. ill go to harbor frieght and get a dwell meter. is there any type i should get?

HF doesn't really sell one worth having, if you ask me. They only have one digital one that measures dwell and I am not convinced of its accuracy. The vendors have their preferred, high end ones - but for the novice, occasional user; people seem to be very happy with this one. It's the one I've got and it was perfect other than having to double the 8cyl scale to get accurate readings.

http://www.amazon.com/Actron-CP7605-Tachometer-Voltmeter-Analyzer/dp/B00062YUUS/ref=sr_1_1?ie=UTF8&qid=1333590238&sr=8-1

You also need a 3mm hex head (preferably with a T-handle) to do the adjustment. That's something that would be worth getting at HF.

coreydmc
04-04-2012, 09:56 PM
perfect! ill order this now. im sure you will be hearing from me when it arrives! :) i just checked to see if the micro switch is connected and it is. there is a green wire and a black wire connected to it. right next to it there are 2 wires that are not connected to anything. they are green and black wires with white and black connectors. does this matter?

DMCMW Dave
04-04-2012, 09:57 PM
Actually we've found that the HF meter works pretty well for dwell - if you read it from the diagnostic connector (orange wire to ground) (it won't read across the frequency valve itself for some odd reason). It's a cheap backup to the Matco meter we have that will read from either location.

Unfortunately you may have to buy 2 or 3 of them to get one that works. :jawdrop:
Which seems to be the case with most things from HF.

coreydmc
04-04-2012, 10:00 PM
well i just bought the one jawn recommended from amazon. it will be here in a few days. i appreciate the help! hopefully i figure it out!

jawn101
04-04-2012, 10:11 PM
Unfortunately you may have to buy 2 or 3 of them to get one that works. :jawdrop:
Which seems to be the case with most things from HF.

LOL, my sentiments exactly Dave. That's why I didn't throw my weight behind it :) And why I said a 3mm hex that will never see any torque was probably a safe thing to get there. I don't think I've ever bought anything at that place that hasn't failed either during or immediately after its first use.

coreydmc
04-04-2012, 10:23 PM
i have another question. i have my new cat and 02 sensor on its way from john at special t. should i install it now or wait until i get my dwell meter so i dont mess up new cat and 02 sensor?

mluder
04-04-2012, 11:33 PM
i have another question. i have my new cat and 02 sensor on its way from john at special t. should i install it now or wait until i get my dwell meter so i dont mess up new cat and 02 sensor?

Depends... Do you drive every day or have annother car.

I suggest doing it all at once. I installed new O2 senor and catalytic convertor at the same time. They are both reached from the same place.

I also installed new fuel injectors as one of the contributing problems I was having were my old injectors were not sealing completely at idle and continued to drip excess fuel into the cylindars. This caused a rich mixture which I could not get rid of.

After instaling the new gear, start the engine and let it warm up for about 15 minutes or so. Enough so that the fans at least cycle once. You may have to give it some throtle to warmit up.

Once you have done this, follow the instructions on setting dwell. Each time you put the plug back in, let the engine settle back down again. When you think you've got it dialed in, disconnect the meter and drive around the block a few times. The car should feel more responsive now. Then back to the garage and keep the engine running. Hook up your meter and check dwell again to make sure it's still in the zone. If not repeat... if so. Have a beer (or beverage of your choice) you're done.

Check out this thread I started before I did mine. http://dmctalk.org/showthread.php?2670-Replacing-the-Catalytic-Convertor
Some good info there.

Also, make sure you read up this forum about replacing the O2 sensor. You'll want to use some anti seize compound but do not get it on the probe tip. Most auto parts stores sell a kit with a little packet of anti-seize and dialectic grease.

Most people have a hard time with seized nuts on the cat and the O2 sensor. I hit mine with penetrationg oil a couple of times the night before I was doing the work and they came right off. Your milage may vary.

Cheers.
Steve

coreydmc
04-05-2012, 09:13 PM
thank you very much. ill work on this after easter. by than i will have the dwell meter, cat, and 02 sensor. I also went to check to see if frequency valve was buzzing and it wasnt. then i noticed the black wire pulled out of the 02 sensor. when i grounded the wire that pulled out of 02 the FV started to buzz. hopefully the new 02 sensor cures this problem

coreydmc
04-06-2012, 10:05 PM
any thoughts on this:

I also went to check to see if frequency valve was buzzing and it wasnt. then i noticed the black wire pulled out of the 02 sensor. when i grounded the wire that pulled out of 02 the FV started to buzz. hopefully the new 02 sensor cures this problem

jawn101
04-07-2012, 12:38 AM
any thoughts on this:

I also went to check to see if frequency valve was buzzing and it wasnt. then i noticed the black wire pulled out of the 02 sensor. when i grounded the wire that pulled out of 02 the FV started to buzz. hopefully the new 02 sensor cures this problem

Have you tried just reconnecting the sensor and warming the engine up? Or is the wire damaged?

Either way it sounds like a new sensor is an absolute must.

coreydmc
04-07-2012, 12:53 AM
yes i have tried fitting the wire back into the sensor itself where it pulled out from, and the fv doesnt buzz. it only buzzes when i ground the wire to the frame. im guessing the sensor is broken.

Bitsyncmaster
04-07-2012, 06:05 AM
The FV should always buzz but if it's running near the max or min duty cycle you may not hear it. You may need to adjust the mixture after you install a new O2 sensor.

coreydmc
04-07-2012, 12:52 PM
the car does not run smooth at all unless i ground the 02 sensor wire where it pulled out of sensor to the frame. when the fv is buzzing the car runs smooth, when i disconnect the wire the car lacks power. does this sound normal if the fv is not working properly?

Bitsyncmaster
04-07-2012, 01:24 PM
the car does not run smooth at all unless i ground the 02 sensor wire where it pulled out of sensor to the frame. when the fv is buzzing the car runs smooth, when i disconnect the wire the car lacks power. does this sound normal if the fv is not working properly?

Probably miss adjusted mixture.

jawn101
04-07-2012, 05:45 PM
Agreed, I don't know how many more threads you need for that answer :)

Put in your new o2 sensor, check the mixture, adjust if necessary. I bet the smell goes away and the power returns.

coreydmc
04-07-2012, 10:19 PM
i know. Sorry i am a pain. you guys are helpful though. i just dont want to install new cat and ruin it because mixture isnt right.

jawn101
04-07-2012, 11:54 PM
No worries. I and everyone else are glad to help. But I'm pretty sure we have your solution nailed down :)

Can't wait to hear how it goes!

Edit: also, you probably won't hurt your cat by running the engine long enough to set the mixture, as long as it isn't glowing from the rich mixture.

Jonathan
04-08-2012, 12:12 AM
Does anyone remember back in the 80's or early 90's where some cars would have an unusual smell and the comment back was "oh, that's the catalytic converter"? It's a vague memory and I don't remember for certain what the smell was and whether it meant the cat was working or that it wasn't working.

When Corey mentioned the exhaust smell isn't exactly the same smell as gasoline, I wonder if it's all cat related? Did I read there you already have a replacement on hand?

jawn101
04-08-2012, 12:24 AM
I was going to wait until after he had some results from the new o2 and mixture adjustment, but I wonder if the odd smell could be mixture combined with hot (but not boiling) coolant. Perhaps in the valley.

Bitsyncmaster
04-08-2012, 05:08 AM
Yes, replace the O2 sensor first and then set the mixture with a warmed up engine. Do you have a dwell or duty cycle meter available? Then you can replace the the CAT if you need to.

coreydmc
04-08-2012, 10:49 PM
Happy easter guys. i received my new special t cat and 02 sensor today. i will try and install them tomorrow. i should receive the dwell meter tomorrow or tuesday. as in one of the posts above sometimes my exhaust smells harsh and sometimes it is a sweet coolant smell. i do have to add coolant from time to time. all my hoses are new. i will do a pressure test tomorrrow 15lbs for 15mins. i was thinking of doing a cyl leak down test to see if i am leaking coolant onto cylinders and thats why i have a strong exhaust smell. i always change oil 2 or 3 times a year and never had coolant in my oil...so thats a good thing!

mluder
04-09-2012, 04:26 AM
Speaking of smells... I forgot to mention, the new cat will be stinky for a bit after you install it. I'm not sure if it's the stuff inside or the galvanization on the outside but it needs to get used to the heat. Goes away after a day or two.

jawn101
04-09-2012, 10:10 AM
Happy easter guys. i received my new special t cat and 02 sensor today. i will try and install them tomorrow. i should receive the dwell meter tomorrow or tuesday. as in one of the posts above sometimes my exhaust smells harsh and sometimes it is a sweet coolant smell. i do have to add coolant from time to time. all my hoses are new. i will do a pressure test tomorrrow 15lbs for 15mins. i was thinking of doing a cyl leak down test to see if i am leaking coolant onto cylinders and thats why i have a strong exhaust smell. i always change oil 2 or 3 times a year and never had coolant in my oil...so thats a good thing!

If you're losing/smelling coolant and aren't seeing it in the oil, then it's gotta be going somewhere... have you checked your valley to see if the water pump hoses are leaking or the Y-pipe is corroded through?

coreydmc
04-09-2012, 06:08 PM
ok the new cat and 02 sensor are installed. i put about 10 miles on car. it seems to run fine. i dont want to drive it to much until i receive my dwell meter in the mail. should the FV buzz with the ignition key turned on? I dont hear my buzzing. also should I plug in the yellow lambda counter box in under the driver side footwell?

Bitsyncmaster
04-09-2012, 06:27 PM
ok the new cat and 02 sensor are installed. i put about 10 miles on car. it seems to run fine. i dont want to drive it to much until i receive my dwell meter in the mail. should the FV buzz with the ignition key turned on? I dont hear my buzzing. also should I plug in the yellow lambda counter box in under the driver side footwell?

No FV buzz until the engine is running. If your RPM relay primes, you will get a buzz during that prime. You would want to reset your lambda counter but you will probably not need a reminder to change the O2.

coreydmc
04-09-2012, 06:41 PM
how do I reset the lambda counter? also the FV doesnt buzz all the time?

Bitsyncmaster
04-09-2012, 06:48 PM
how do I reset the lambda counter? also the FV doesnt buzz all the time?

I think there is a reset button but I long ago removed my lambda counter and gave it away.

Your FV should always buzz (with engine running) after you get the mixture adjusted.

coreydmc
04-09-2012, 07:00 PM
my lambda counter has always been unplugged for the 15 years i have owned the car. should i leave it unplugged? unplugged light off, plugged in light on. also with car running i dont hear or feel FV buzzing. I guess i need my dwell meter for that right?

opethmike
04-09-2012, 07:02 PM
Just leave that counter unplugged. All it does is turn on that lambda light.

jawn101
04-10-2012, 12:06 AM
The FV not buzzing is likely a mixture problem. Just sit tight and set it when the dwell meter arrives.

The counter is not a functional part of the lambda system, it is just a mechanical counter that lights the dash telltale. It is clearly working so you can reset it with a paper clip and hook it back up once the new o2 sensor is installed, if you like. Or leave it unplugged, it makes no difference.