BrianSw

Hi, New here for a reason because I gave up with the Chevy Dealer service center. They can'tpin 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 about2 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 stillhave the loss of power problem. Thought maybe someone here might have some clue as to what might be causing this. The dealer saidthe car runs good until it gets warm then runs reallybad. 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 onwith this vehicle. Any advice or suggestions would certainly be appreciated.

Thanks,
Brian

EvansBlue

You're not overboard. I'd say you may have a bad temperature sensor, a badO2 sensor, a clogged catalytic converter, a bad EGR valve, or bad PCV valve. It could be a combination ofthe five. I'd say definately check your PCV valve and your sensors.

BrianSw

I cleaned out the PCV valve with Carb Cleaner don't know if that was an acceptable method. That was done when I replaced the fuel pressure regulator. It looked OK, not all gummed up.
Don't know exacly how it works but seems to be a kind of check valve. There is a plate inside it and I think it's spring loaded maybe. I can push on the plate and it moves in and then it reseats itself. A O2 Sensor did show up as a fault code on the scanner both from the dealship and a free check by Autozone parts store. Someone else also told me to check the Cat convertor also. I'll do that today I guess when I get the car back home from the dealer today. Hopefully they will at least give me a Diagnostic report of some type. Temperature sensor was not checked by me yet. Not sure where that one is located (engine block?). Have not checked the EGR valve either. Have to locate that one also and see if I can find some info on how to check that one. I was going to go buy a Code scan tool for my own use hoping it might help me out in troubling this. I would like to try and clear all the codes and start from scratch. I have to get another Fuel Pressure tester also as mine is now broken because the little pin, rubber O ring, and a small circular platein the valve connector fell out somewhere.

Thanks, will have a look at the things you mentioned and report my findings back afterwards.

Brian

EvansBlue

The temp sensor should bemade intothe side of the intake duct, you'll see the two or three wires leading from the intake duct. Your O2 sensor fault WILL make it very sluggish. The Exhaust Gas Recirculate valve (EGR) is located either on the back or side of the throttle body. Could possibly be down around the block with a tube going up to the intake. Not sure about it on a 97.

BrianSw

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 supected VCM module.

Now onto the working on it. Will check the things you mentioned and the circuits to the O2 sensors.

Thanks,
Brian

aj_wicked13

Im not sure if this would be it but check your distributer... In my 68 Camaro (with HEI) i had that identical problem... would start up fine and run fine in park but as soon as i would get going (or about 5-10 mins later) it would lose rpm and almost stall out. after about 500 bucks in replaced parts it was the pickup at the base of the distributer (cost maybe 15 bucks). Im not sure if your 97 has a similar pickup but it has to have somthing that is telling the computer where it is in the cycle. maybe a camshaft sensor, hall effect switch, or Ignition Control Module. If you take the ignition control module off im sure you could take it to advance auto or autozone and they will check it for you for free. at least the one where i used to work at did. When they get warmed up after being under load they would fail. but run fine while cold or under no load. Just somthing else to check. Good Luck with your problem.

BrianSw

Thought the same thing about the ICM, I did replace it once acouple of years ago. I know it gets really hot. Thats why I keep thinking it might be that. After I turn of the engine maybe enough for it to cool down abit it starts working better. Could be reason for multiple misfires on all cylinders as I have the code.

Thanks,
Bryan

aj_wicked13

On my camaro it wasn't the ICM itself it was the connector that got the signal from the Pickup. Take the ICM off and have it tested. Luckly that not somthing that going to cost you any money to have checked.... although i personally know that the testers at Advance Auto (at least the one i used to work at) do no get the ICM very hot(even if you check it several times).... so you may get a false reading for that factor...

BrianSw

Wonder what would happen if I heated it up really hot if it would fail right away without even having to have to run it for 20 or so minutes till got hot by itself. Or, maybe cool it down when it is failing with some electronic freeze spray. Gonna maybe try that and see what happens.

Brian

chevyluver

Hi, i just joined here and have the same problem with my 2000 4.3l s10. I was wondering if brian ever figured out his problem with his blazer or if anyone else has a solution. Any help would be great, thanks.