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97 Blazer Loss Engine Power after warm up.

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97 Blazer Loss Engine Power after warm up. - 11/30/2007 9:33:17 PM   
BrianSw

 

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Joined: 11/30/2007
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Hi, New here for a reason because I gave up with the Chevy Dealer service center. They can't pin point the problem I having and just want to start popping in parts with no gurantee that it would even fix the problem.

Here's a short history of what happened. My blazer had really bad problems starting I had to spray starter fluid into the throttle body to get it started. Then it would run fine. Only had to do that when starting it. Eventually the engine would not start at all. So, I went to work on it.
I checked fuel pressure and it was really low. I replaced my Fuel Pump. This was my second fuel pump replaced within a one year period. Fuel Filter was replace at the same time. 

I decided I might as well replace my Fuel pressure regulator because I already knew I had problems with the one I had. I could not maintain pressure after turning off the engine. The pressure would drop to zero really fast.

Spark plugs, Distributer rotor and cap, TPS sensor, ignition switch, battery, and alternator were also replaced recently.

The vehicle ran like a champ afterwards. Started on the first turn of the key. WooHoo!
But that didn't last long. After driving the vehicle for about 30 minutes on the highway I would start losing power. I'd be driving at 65 then all of a sudden my RPM's start falling, Engine speed is dropping by itself. I try give it more gas but that would make it worse. Eventually I could only get to about 10 mph speed. And if I floored the pedal it would almost stall out.
I pulled over to the side of the road and turned the engine off. Let it sit for about 2 minutes and started it back up again. Now if was good again. I could get back up to 65 mph and drive normally again. It was doing this every day during the hot summer weather. As the temperature outside started dropping (Fall season) the problem went away. Things were good for a few weeks.

Now it's really cold outside and the problem came back again only really bad this time. I can start the car fine. It will run good for acouple minutes. I can get up to 55 mph then I start losing power again. Can't even get it to go up a small hill in the road. I pull over off the road and let it sit for a few minutes then restart it. I can drive for about another minute or two and start to lose power again. I was able to get it to a near by dealership they had it for a week already. I told them everything I replaced. They supected leaky fuel injectors. I asked them if they can test them and find out which one was leaky. They couldn't because they didn't want to spend the man hours taking them apart incase they were good. They wanted me to take the car back and test them myself. So, I was ready to just go and get the car and try and get it home. Already the have billed me $300 in labor for nothing. Well when I went to pick it up they wanted to keep it for another day because supected that maybe it wasn't bad fuel injectors and said it could be the VCM Module. I asked it were sure thats what the problem was. They said no not really and might not fix the problem at all. But they wanted to put one in at my cost anyways (another $500) no gurantee it would solve he problem. Well I told them no, and I'm going to pick up the car tomorrow.

So, now I'm out $300 and still have the loss of power problem. Thought maybe someone here might have some clue as to what might be causing this. The dealer said the car runs good until it gets warm then runs really bad. I believe the said to was throwing a whole bunch of codes.
Also I did notice that when this power loss problem had gotten really bad my "Service Engine Soon" Light flashes. I've never seen it flash before. They (the dealership) said that was a sign of a really bad problem.

Sorry if I went overboard here with all this but thought it would give some idea of what went on with this vehicle. Any advice or suggestions would ce

< Message edited by BrianSw -- 11/30/2007 10:09:57 PM >
Post #: 1
RE: 97 Blazer Loss Engine Power after warm up. - 11/30/2007 10:16:47 PM   
Hanr3


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My first instinct is cat. Your cat is plugged up. The exhaust fumes back up into the engine and you lose power. Turn the engine off, or let it idle at low rps and it clears out enough for you to drive a little further.

My second instinct is ICM- first sign it is going bad is lose of power, engine dies, goofy timing, when hot. Once cool it returns to normal, until it gets hot again and the cycle repeats.

Beat on the cat with your fist, if it rattles, replace it.

Take the ICM to your local Autoparts store and have them test it. Make sure they do the test like 6 times in a row. You want it to get hot.

Anotehr test for a plugged cat is to disconnect your battery for 20 minutes. If you cannto start the trcuk again your cat is plugged. The puter monitors engine peramiters, it makes adjustments to keep it running properly. When you disconnect the battery the puter loose memory of what it learned, and it goes back to defualt mode. If it dont start, its becuase defualt mode is so far out of whack from what it learned.

These are strictly shade tree mechancis at its best.


< Message edited by Hanr3 -- 11/30/2007 10:19:22 PM >


_____________________________

"Some people spend an entire lifetime wondering if they made a difference.
The Marines don't have that problem."
-President Ronald Reagan

'87 S10-Blazer - SOLD
'93 S10-Blazer 4x4x4 - Sons DD, engine swap is done.
'00 S10-Blazer 4x4x4 - My

(in reply to BrianSw)
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RE: 97 Blazer Loss Engine Power after warm up. - 11/30/2007 10:28:16 PM   
BrianSw

 

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Thanks, will give these a look at when I get the car back from the Dealer tomorrow. Will report back on my findings. It's going to be a long trip back home with it as I'll have to pull over and turn of the engine and restart about every minute or two for about 10 miles.

Brian

(in reply to Hanr3)
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RE: 97 Blazer Loss Engine Power after warm up. - 12/1/2007 4:33:19 PM   
BrianSw

 

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Just got it back from the dealer. They must have cleared the codes on it because I didn't get a Engine Check light on. But I drove it for about 5 miles (it ran good) then the Check Engine light came on and was flashing. I started again to lose RPMs again, I slowed down and the flashing stopped then it was just a steady on light (not flashing). If I tried to accellerate faster, I couldn't gain up more speed. If I let up on the throttle just a little then my RPM's would go up slightly. I got it up to my driveway to my house but couldn't get it to go up it. I live on a little hill and the driveway is inclined up. I turned off the engine for about 2 minutes then started it back up. Then I had more power to get it up the driveway. It's now in the garage.
I have the receipt from the dealer. What a suprise. They decided not to charge me anything for the week they spent looking at it. Good decision by them I guess because they couldn't find what is causing the problem.
I had them copy the codes onto the receipt. So, here they are.
P0442 Evap System small Leak, (gas cap)?
PO122 TPS Low input voltage ( was replace with a new one by me)
PO131 O2 sensor circuit low voltage (Bank1/Sensor1) 
PO300 Random / Multiple cylinder misfires (Reason for Flashing Check Light?)
PO137 O2 sensor circuit low voltage (Bank1/Sensor2)
PO141 O2 Sensor heater circuit malfunction (Bank1/sensor2)
PO143 O2 Sensor Circuit Low voltage (Bank1/Sensor3)
PO151 O2 Sensor Circuit low voltage (Bank2/ sensor1)

Can't see how all my O2 sensors could have went bad at the same time. Maybe I have bad connections to them? Or, maybe because the car was backfiring when this problem first started. Only did it a few times when I tried to give it more throttle.

Still, car warms up then throws these codes.

They (dealer) supected VCM module.

Banged on the CAT and didn't here anything rattle. It's pretty tight and maybe I'm just not hitting it hard enough to move it. Keep thinking the ICM too. I removed it and cleaned the surfaces and replied alot of heatsink grease to it. It didn't have much on it and was abit dried up. I don't think I'll take it for a ride just yet. I did notice that on my way home I got the flashing Check Engine light then it went solid after reducing speed. Started out with no light, Dealer cleared codes I think. I believe it was doing the misfire on cylinders first then the other codes (TPS/O2 sensors) must have followed. I'm an electronic technician so I'm pretty good at trouble shooting electrical stuff. I know of a test I would do when I suspected a electrical component breaking down due to heat. I would spray the component with a can of freeze spray and if it then functioned normally it would be the bad part. Thinking of doing the same with the ICM and see what happens after it heats up and the car starts missing  or misfiring.
Thing is I'm all out of freeze spray at the moment. But I have a can at work. It's 30 miles away though and don't think I'll try and drive there tonight.


Thanks,
Brian 

(in reply to BrianSw)
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RE: 97 Blazer Loss Engine Power after warm up. - 12/1/2007 5:08:55 PM   
Hanr3


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Sounds like the cat is ok then. At least ift passed the beat test anyway.

P0300 eh?
Maybe try a test, how long can you drive it at a slower speed?


_____________________________

"Some people spend an entire lifetime wondering if they made a difference.
The Marines don't have that problem."
-President Ronald Reagan

'87 S10-Blazer - SOLD
'93 S10-Blazer 4x4x4 - Sons DD, engine swap is done.
'00 S10-Blazer 4x4x4 - My

(in reply to BrianSw)
Post #: 5
RE: 97 Blazer Loss Engine Power after warm up. - 12/1/2007 6:25:28 PM   
BrianSw

 

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Well today bringing it home I drove about 8 miles going about 50 to 55 for about 6 of those miles. It started acting up and I reduced speed to about 30 for the rest of the trip and made it home till I got to my driveway. Then turned it off for about 2 minutes to allow to cool down. Then got up the driveway. It is a problem when the engine gets to it's normal operating temperature I guess. Then it loses power, sputters, misfires, etc...

Ran it in my driveway just alittle while ago and got it hot. It was putting much out smoke out of the exhaust. Maybe just water vapor I don't know. Maybe just a lot of water buildup in the exhaust system from condensation I think. Hope it's not coolent. Didn't normally do this alot. Only sometimes. Really cold outside today. Maybe about 20 degrees now. I'm in Buffalo, NY area.

Brian

< Message edited by BrianSw -- 12/1/2007 6:31:08 PM >

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RE: 97 Blazer Loss Engine Power after warm up. - 12/1/2007 7:24:23 PM   
swartlkk


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This definitely looks like there is either a wiring or a PCM failure...  Check over all of your grounds first and foremost.

If you have a pick-n-pull type yard close by, you may want to get a replacement PCM from there and see if that helps.


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RE: 97 Blazer Loss Engine Power after warm up. - 12/1/2007 9:59:20 PM   
BrianSw

 

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Looked at alot of sensor connections today and didn't see anything abnormal. Cleaned them anyways. Pulled off EGR valve to check if it was stuck but was able to push on the little plunger and it is good mechanically.

By PCM do you mean VCM? Or, is PCM something different. This gets confusing as VCM can be called ECM too I guess. Again the Dealer suspected a faulty VCM but didn't offer any gurantee that replacing it would fix the problem so I said no thanks. Can't afford trial and error troubleshooting. Even though process of elimination might help but would be costly.

This problem manifested I think after I changed the fuel pump, Fuel Filter, and the fuel pressure regulator.
I also had put in a new alternator, battery, distributer cap & Rotor, and Spark plugs just before I did the Fuel pump and pressure regulator. Before doing all that I didn't have this kind of problem. Well at least before my Fuel pump failed.

I keep thinking maybe it was something I did during all that work that I maybe overlooked. Like forgetting to reconnect something. I looked and looked but can't see anything I could have missed. Just appears to me like something is warming up then failing when the engine gets hot.
The only thing I replaced now was the TPS sensor because it came up in the codes. But I think the reason for the TPS code was because I was trying to accelerate and the engine wasn't responding the correct way and thinks the TPS was failing.

Gotta be a Nasa Rocket scientist these days with cars.

Well have to use my wife's car tomorrow and leave mine home to rot in the garage while I'm at work.

Thinking of getting a Code scanner but maybe someone can talk me out of it. Maybe something I can use to monitor things while I drive the car until it gets hot and starts to fail again. Would be nice to get somekind of report of what the sensors are doing.

Brian

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RE: 97 Blazer Loss Engine Power after warm up. - 12/2/2007 11:55:54 AM   
Hanr3


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The puter stores all teh parameters when a code is tripped. Go to Autozone and get them to read the codes, then ask them to read the freze frame data (not sure of the proper term). Its the information the puter stores when the code is tripped. While your at Autozone get them to test your ICM. When hot it dont want to play nice, when cool it will work great. It controls your ignition timing. Early sign of falure is acting up while hot and going back to normal when cool. 

_____________________________

"Some people spend an entire lifetime wondering if they made a difference.
The Marines don't have that problem."
-President Ronald Reagan

'87 S10-Blazer - SOLD
'93 S10-Blazer 4x4x4 - Sons DD, engine swap is done.
'00 S10-Blazer 4x4x4 - My

(in reply to BrianSw)
Post #: 9
RE: 97 Blazer Loss Engine Power after warm up. - 1/25/2008 7:44:14 AM   
BrianSw

 

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OK, I fixed my misfire problem. Had several misfires cylinder 1,2 and random. Turned out to be the new set of 6 Bosch Platium sparkplugs. Replaced them with ACDelco plugs and haven't had a misfire code in a few days. But I still have a loss of power problem and getting a new code on the scanner I bought. It's P0153.
After reaching operating temperature it bucks, backfires (sounds like coming from the throttle body) front of engine. If I floor the gas the RPMs jump all over the place (goes up & down) and I hear backfire sounds.
So far I replace the TPS, IAC, New Plugs, New Plug Wires, Fuel Pump a few months ago, fuel filter, Fuel pressure regulator.

Could the O2 sensor (slow response) cause this probem? Can't get this vehicle inspected until I can get this thing from throwing codes. It's almost 30 days past inspection (overdue). In about a week I'll be getting a Notice from NY DMV that they are canceling my registration because it not inspected. Really need some advice here. Would be greatly appreciated.

Thanks,
Bryan 

I can post freeze frame data if that would help for the code. I also collected live data when the car was bucking,backfiring,etc...
Basically I floored the gas and triggered the coderscanner to grab the data. So, it verry erratic.

< Message edited by BrianSw -- 1/25/2008 8:10:58 AM >

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RE: 97 Blazer Loss Engine Power after warm up. - 1/25/2008 10:22:58 AM   
swartlkk


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Does your scan tool have the capability to look at the sensor trace from B2S1.  If so, how does it look?  Smooth transitions or random sharp peaks?  If it is random sharp peaks, the sensor is gone.  If they haven't been changed, I would recommend you change the upstream sensors, both B1S1 & B2S1 which are located in the y-pipe.  B1S1 is on the driver's side while B2S1 is on the passenger side directly ahead of the 'y' in the y-pipe.

As I suggested earlier, it is possible that the PCM (VCM,ECM whatever you want to call it) is at fault for this.  The cheapest route to go would be to grab one either online or from a local recycler in your area and install it.  Worst case is it doesn't work.  Best case is it works and you then need to have a CASE learn done for the new PCM to learn the specific correction factor between true engine position and what the crankshaft position and camshaft position sensors are telling it.

I still think this is a grounding problem somewhere that is affecting the sensors and possibly the ignition system.


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RE: 97 Blazer Loss Engine Power after warm up. - 1/25/2008 10:49:23 AM   
BrianSw

 

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I can record live data for 20 frames. Should I do this when the car is idle and at operating temp? It idles fine. When I accelerate ( step on the gas quickly) even in park after it's warmed up it will hesitate and bog down, backfire, and acting like it's not getting any enough gas. I can get it to sometimes reach higher RPMs if I slowly increase the throttle instead of stepping on it hard and fast.

Really though it was the misfiring thats was causing that problem. Now the misfiring is corrected I still have it.

What about a plugged up cat? Can it get worst when the car reaches operating temp and work OK when the car is cold (less plugged up)?

Thanks,
Brian

(in reply to swartlkk)
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RE: 97 Blazer Loss Engine Power after warm up. - 1/26/2008 9:20:13 AM   
hernandez3674

 

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Its the Cat... I worked on a 2000 with simialar conditions.. I believe the code it stated was a lean condition.. Took it to Firestone and they wanted said a vacuum leak. I took it to the dealer and it was the converter.. And the best part of it was it was still under warranty and they paid for it..Runs perfect now.

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RE: 97 Blazer Loss Engine Power after warm up. - 1/27/2008 10:54:32 AM   
swartlkk


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A plugged cat wouldn't perform good at one point, then all of the sudden clog up, only to unclog a few minutes later...  One way to know for sure is to remove the O2 sensor directly ahead of the catalytic converter (B1S2) and drive it like that.  If the problem is aleviated, it's your cat.  Catalytic converters are warrantied much longer than the factory warranty, but I don't think yours would still be covered.

I'm leaning towards a ICM problem.  You can remove the ignition control module and take it into Advanced or Autozone and have it tested.  Have them test it 10-15 times in a row and see if it still passes.  The ICM is mounted onto a small heat exchanger for cooling.  Your problem seems to be related to heat.  Also, there should be some thermal paste between the ICM and the plate it mounts on.  If this is missing, try putting some dielectric grease (temporarily) onto the back and see if that helps.


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RE: 97 Blazer Loss Engine Power after warm up. - 1/28/2008 7:45:59 AM   
BrianSw

 

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I haven't check the ICM yet but did pull it off clean off the old heat sink compound and reapply new stuff.  Well I Replace both Upstream O2 sensors and the vehicle seems to be running much better. No codes! Also after a 30 mile drive to work no signs of the engine losing power anymore. Not yet anyways. It was doing it everyday driving to work and back and today it was fine. Could the O2 sensors be the cause of such a problem. Maybe when they finally heat up? It like it was the engine was starving for gas. Hopefully now I can get it in to get it inspected but still have to get the computer to run it system checks. I tried to do the GM drive thing to get the IM ready tests performed but never works for me. Still have Cat, EGR, and Evap to pass yet.

Thanks,
for the help. Hope this is the conclusion of this problem.

Brian

(in reply to swartlkk)
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RE: 97 Blazer Loss Engine Power after warm up. - 1/28/2008 8:15:39 AM   
swartlkk


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Glad it's working for you now...  With all of those codes...  Well, time will tell.

It is possible that the ICM wasn't being properly cooled prior to you cleaning it and reapplying thermal paste.  It is also possible that the misfires eventually fouled out the O2 sensors. 


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RE: 97 Blazer Loss Engine Power after warm up. - 1/29/2008 8:26:22 AM   
BrianSw

 

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Well, back to the drawing board again. Yesterday it started doing it again on the way to work (about a 15 mile drive). The engine performs much better after replacing both upstream O2 sensors. But again it is choking after the engine gets hot. Today I'll pick up a ICM. The only question I would have about this is if the ICM was overheating and going bad wouldn't it be causing misfires? I'm no longer getting any fault codes.

Thanks,
Brian

(in reply to swartlkk)
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RE: 97 Blazer Loss Engine Power after warm up. - 1/29/2008 9:17:13 AM   
HeyYou

 

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I don't think the computer really tracks the ICM, it either gets a signal, or, it doesnot... If not, then the computer assumes the engine is not turning, and won't give spark, or, injector pulse. So, if you are getting Injector pulse, but NOT spark, chances are pretty good, that it is NOT the ICM.

(in reply to BrianSw)
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RE: 97 Blazer Loss Engine Power after warm up. - 1/29/2008 9:28:31 AM   
swartlkk


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The ICM (ignition control module) has nothing to do with the fuel injectors and is solely responsible for the spark timing.  If the ICM is failing to initiate the spark at the proper time, it will result in very poor drivability.  If the spark is occuring either way advanced, or way retarded, you won't get hardly anything for power out of it.  If it is at full advance, then there would be detonation.  If it is at full retard, then you just won't get anything for power.  You would need a high featured scan tool to see if the timing is actually changing during operation and a timing light to verify the spark timing.

ICMs are easy enough to get tested at your local autoparts store as I suggested a few days ago.

< Message edited by swartlkk -- 1/29/2008 9:35:24 AM >


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RE: 97 Blazer Loss Engine Power after warm up. - 1/29/2008 10:58:48 AM   
BrianSw

 

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The scan tool I have  EQUUS INNOVA 3130 shows my ignition timing (ignition advance in Degrees). Don't know if that would offer insight as to what is going on if I monitored it. As I'm driving the amount degrees changes. I understand the concept of what you are saying but thought ignition timing was fixed. It does fluctuate some. I have captured frames with this code scanner when the problem occures but it is so erratic it is hard for me to figure out what exactly is happening. I believe I did capture frames of data (sensors) including the ign timing both when the car was functioning normally and when it was not. After capruring the data I was then plotting it with Microsoft Excel. Was doing that incase I took the car to the dealer for them to look at. But, from my past experience with them they wanted to replace things and not say it would fix the problem for sure. When I had it there they wanted to replace a single fuel injector not knowing if the one they wanted to replace was defective or not. Then they wanted to replace the PCN/ECM (the car's computer). There service manager said he wouldn't bet his pay check that it would fix the problem either. So, anyways thanks for the explaination about the timing and will try out a new ICM. I'll see if the autoparts store will test it out. I may just buy one anyways because it does't fail I guess until it gets really hot.
My past expeerience with these ignition modules was that they just tended to completely die, and never seen one that was just breaking down after sometime driving.

Thanks,
Brian

OK looking at the captured frame data (20 frames) when the engine was cold and at idle and when it was hot after a 15 mile drive shows that ignition timing advance on cylinder #1 was pretty much identical. Varied by between acouple degrees 19 - 22.




< Message edited by BrianSw -- 2/2/2008 3:59:36 PM >

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