The scan tool I have does have the option to read pending codes. It reports no pending codes. I haven't driven the car in a few days as I've been working long days. The only thing I can do is drive it around town for now.

I could check the wiring going to the knock sensor. Any idea where that is located on the engine? On my ford 3.8 it's on the side of the block. I would assume it's the same on the chevy.

 

These threads may help you find it
click-->https://montecarloforum.com/forum/mo...inquiry-53742/


click-->https://montecarloforum.com/forum/mo...o-3-8-a-48379/

 

Tried a different OBD2 scan tool today and found a pending code of B1001. Everything I find on google doesn't seem to relate to my problem.

As usual I drove the car around town for 20 miles today with no problems.

 

I looked up B1001 in the shop book. It's a BCM code and at a glance looks like it's a problem with either the radio, air bag system or OnStar getting/validating the VIN from the BCM.

Should not have any impact on a random mis-fire.

I hate being out of ideas

 

I know. I put 40-50 miles on it all weekend and it runs like a champ! I just know that as soon as I drive it the 80 miles to work something will let go then I'll end up paying 200-300 bucks to get it towed home. At least if it takes a dump within 20 miles of home I get a free tow.

 

Had time to mess with the car today. Drove it about 10 miles and halfway through it started missing for about 30 seconds then cleared up again.

When I got it home I took the cover off the engine and just listened and heard a ticking sound. Got slight louder and I pin pointed it to the purge valve constantly purging on and off. I replaced this last year when I got a code for a large evap system leak and that fixed that problem. If I unplug the purge valve solenoid it stops ticking and starts again as soon as I pug it in. I turned the car off and back on and for about the first 1-2 min the purge valve was fine then started purging on and off again. It does it about as fast a 4 times a second. What would cause the computer to command that valve to constantly purge after it runs for a couple of min?

 

Well after searching the net it seems the purge valve is acting normal. Guess it will be off to the "Stealership" later this week to see what the problem is.

 

At the suggestion of my father I've been in touch with Pat Goss (Goss's Garage from Auto Week on TV). He's given me the below advise and if it stops raining outside I've got a few new things to check. From what he has written it has something to do with the MAF sensor or the connection to it.

You can read the mail thread below from bottom to top:

Jason:

You plug the test adapter into the end of the wire connector then connect a Digital Volt Ohm Meter (DVOM) to each connector (one at a time) then using a piercing tap make a connection to the wire about 2 inches from the plug. Next wiggle the wire and look for any change in resistance. None found; heat the connector with a heat gun and repeat. Still no reaction use a cold gun and freeze the connector and repeat.

Sincerely,
Pat Goss

MotorWeek Television
News Channel 8 Television
Goss’ Garage Radio radio.goss-garage.com

Live Chat Thursday morning at 11:00 Goss' Garage - Auto Repair & Maintenance, Lanham, Maryland
FREE NEWSLETTER register at Goss' Garage - Auto Repair & Maintenance, Lanham, Maryland

Goss' Garage
9421 Smith Avenue
Lanham-Seabrook, MD 20706-4045
301-577-9200
PatGoss@Goss-Garage.com
Goss' Garage - Auto Repair & Maintenance, Lanham, Maryland

From: Jason
Sent: Thursday, October 01, 2015 5:42 PM
To: 'Pat Goss'
Subject: RE: Monte carlo problem

I can’t find any problem with the connector. I checked the hot and ground and they are good. It’s not cracked anywhere I can see.

I did look today and by looking at the sensor tops and from what I found on line it seems that the part that came off was an AC Delco (Hitach) and the one I replaced it with is a Delphi.

If there is anything specific I can check on the connector please let me know. When I have my reader hooked to the OBD II port it always sees a signal coming from the air sensor. Perhaps if it’s the wrong brand it’s sending the incorrect info?

Thanks again for your advise.

Jason

From: Pat Goss [mailto:patgoss@goss-garage.com]
Sent: Thursday, October 01, 2015 10:18 AM
To: 'Jason
Subject: RE: Monte carlo problem

Why not check the connector based on your description it’s the most likely problem? We used to do them by the hundreds.

Sincerely,
Pat Goss

MotorWeek Television
News Channel 8 Television
Goss’ Garage Radio radio.goss-garage.com

Live Chat Thursday morning at 11:00 Goss' Garage - Auto Repair & Maintenance, Lanham, Maryland
FREE NEWSLETTER register at Goss' Garage - Auto Repair & Maintenance, Lanham, Maryland

Goss' Garage
9421 Smith Avenue
Lanham-Seabrook, MD 20706-4045
301-577-9200
PatGoss@Goss-Garage.com
Goss' Garage - Auto Repair & Maintenance, Lanham, Maryland

From: Jason
Sent: Wednesday, September 30, 2015 9:58 PM
To: 'Pat Goss'
Subject: RE: Monte carlo problem

Thanks for the advice. I do still have the part I took off. I can’t find Delphi or Hitachi on the old one. However googling the part number points it to being an AC Delco brand part. The replacement one I order is made by Walker Products. Perhaps it wasn’t the best idea to buy the cheapest one I could find. Seems strange that after replacing it the car would run fine for 6-7 months but maybe this one is just not durable enough.

Thanks a lot.

Jason

From: Pat Goss [mailto:patgoss@goss-garage.com]
Sent: Wednesday, September 30, 2015 2:24 PM
To: 'Jason
Subject: RE: Monte carlo problem

Jason:

Begin by testing the wire connector at the MAF (huge problems) and second if you have the original MAF sensor compare brands to the new one. There were two brands (Hitachi and Delphi) and they often do not work right if interchanged.

Sincerely,
Pat Goss

MotorWeek Television
News Channel 8 Television
Goss’ Garage Radio radio.goss-garage.com

Live Chat Thursday morning at 11:00 Goss' Garage - Auto Repair & Maintenance, Lanham, Maryland
FREE NEWSLETTER register at Goss' Garage - Auto Repair & Maintenance, Lanham, Maryland

Goss' Garage
9421 Smith Avenue
Lanham-Seabrook, MD 20706-4045
301-577-9200
PatGoss@Goss-Garage.com
Goss' Garage - Auto Repair & Maintenance, Lanham, Maryland

From: Jason
Sent: Tuesday, September 29, 2015 10:07 AM
To: patgoss@goss-garage.com
Subject: FW: Monte carlo problem

Hi Pat,

My father has contacted you a few times over the years with car problems and you have always been very helpful. I’ve got a very intermittent problem with my car and after I sent this to him he suggested I send you an email. I’m about ready to take it to a dealer but it’s so intermittent that I’m afraid that while they have it, it won’t act up and I’ll just be out of pocket money with no answer.

Please help. I have the skill to rebuild an entire engine but I can’t figure this one out.

Jason Miller.

From: Jason
Sent: Friday, September 25, 2015 8:40 PM
To: Marvin
Subject: Monte carlo problem

https://montecarloforum.com/forum/mo...misfire-54095/

You can read all the feedback I’ve gotten so far using that link to see the website.

Here is what I wrote.


I have a 2004 non SC SS. 3.8L engine

For the past 2 weeks I've had a really random misfire, or what feels like a misfire, problem

I drive 160 miles to work and back. One morning while in some light traffic about halfway to work I feel something not normal. As I come to the next traffic light and I'm stopped I can feel a slight mis and I can see the tach move down 100-200 rpms when I feel the mis. I turn off the radio and AC and keep driving the car with the mis so I can find a good place to pull off the road. within the next 2 miles the mis go away. I pulled onto the highway and drove 70mph the next 40 miles to work with no problems. Even turned the AC and radio back on.

On the way home from work about 10 miles in I hit stop and go traffic on the highway. Once again I feel the mis. This time it doesn't go away. For the next 5 miles I'm stuck in traffic for about 20 min until it opens up. the entire time the mis is getting worse. By the time traffic is really moving I can't accelerate past 50 mph. I end up pulled over on the side of the highway. Radio and AC off and it's missing bad. I try to rev the motor while in park and it has a hard time reaching 3000rpm. After sitting there for 3-4 min it dawns on me it's acting sort of the same the way it did 6 months ago when the mass air meter went bad. I remember the test for that was to unplug the MAF and see if the engine would start. So I leave the car running, pop the hood, unplug the maf, jump back in the car and the mis is gone. I put it in gear and drive home 50 miles with the MAF unplugged. Seems to run just fine. I let the car sit for 2 days then last weekend I decided to check the car out. Plug the maf back in, start the car and it's like it never had any problem. So all of last week I drive it to work putting 500+ miles on it with no problem. Then yesterday a week later I'm driving it to get coffee and back (6 miles round trip) and 2 miles from home at 45mph it starts missing again. It does this for about 30 seconds then clears up.

At no time during any of this did the check engine light come on.

I put the code reader on it and there are not codes. Not even any pending faults

I'm stumped on what to even start checking. I did check the output from the maf sensor and it's reading 2.4-2.5 hz at idle and climbs normally when you rev the engine.

any ideas?

 

I thought I would share as I believe I have fixed the problem. I purchased a Hitachi brand MAF and have now put almost 1000 miles on the car and the misfire has not returned. Who knew that a different brand MAF would cause such a problem.

 

I was going to say, I just installed an ACDELCO not remanufactured, MAF on my MC SS and it has stopped my issues with dying randomly. Glad you got yours figured out! I too am amazed that brands make that much of a difference.