Here is my issue: I got the Blazer fairly cheap because the guy was not mechanically inclined and did not want to fool with it.
Anyhow, it starts only when you hold the pedal down. Once it does start it has a strong fuel odor and the ground is black from all of the carbon coming out of the tail pipe.
I replaced the coolant temperature sensor and rebuilt the fuel pressure regulator. Still the same issue. Today I took it to a shop I deal with from time to time and my buddy put a computer on it. Only code it came back with was MAP sensor or high voltage. I replaced the MAP sensor and it still has the same issue. I have checked the EGR valve by pushing in on the diaphragm and best I can tell it is fine. The truck will not run worth a bean with both injectors plugged because they are spraying so much fuel. With one injector, you can get it to putt down the street.
My next step is to just replace the computer, but I wanted to see if someone could shed some light on this issue or perhaps someone that has been through the same thing.
Okay, I am back on this project now that the holidays are over. After testing voltages and hooking a computer up to the blazer, I was left with the computer being bad. I put a new computer in today and the car started up and ran like bad for a couple minutes and then cleared up. I turned it off for a couple minutes and tried to restart and nothing. I replaced all of the plugs using AcDelco. Once again, started up and ran fine. It would even sit there and purr like a kitten. This did not last long and it would try and stall out, and then clear up and run fine and then repeat the cycle. I was able to drive it home from the shop about ten minutes away and it ran good with the exception of the pinging and valve clatter. Not sure if it might have some water in the tank or not. I got home, turned it off and let it sit for about a hour. Went back outside to start it up, and would not start unless I held the pedal down. I am really not sure what direction to go at this point. Would the IAC cause this and OR the EGR valve?
Right after I put the new computer in, the truck started up and ran fine. It sat there and idled for about ten minutes with no issues. Today, I pulled all the plugs out and cleaned them, fired the truck back up and the injectors were once again dumping fuel. Just cranking the motor the injectors were dumping fuel like crazy. Keep in mind it did not do this after I put the new computer in at first, but it did the exact same thing with the old computer in. I had them order me another one and will pick it up in the morning. I am really confused at this point and I hope it was just a faulty computer.
I put the new computer in and still the same. It will idle somewhat decent on 1 injector but is still dumping fuel. I ran the truck about 5 mins or so and could smell something funny and then seen smoke coming from underneath the truck. I looked underneath and it was REAL hot from the converter back. First time it's done this. I hope the converter is not bad now because the whole exhaust system was replaced last year.
Tonight I checked the map sensor using a voltmeter and a vacuum pump and it seems to be fine pressure and voltage wise. I have pulled the EGR off yet but I did apply pressure to it with the vacuum pump and I could see the diaphragm open and close and it seemed like it was moving pretty smooth.
Far as IAC, I could visually see the pintle moving in and out when I would bump the throttle. I havent checked the TPS yet, I will do that tomorrow.
Sorry for the long post, but I figured the more I could explain what I have done, the more it would help someone to be able to help me.
UPDATE today 1/21/2010
I spent nearly all day rechecking, back probing sensors, checking vacuum on the MAP, EGR solenoid, EGR valve seems to be working fine. All of the sensors are within specs far as voltages are concerned. The service engine soon light was out on the dash so I replaced that today. Put the new computer in and I still get the same result, dumping too much fuel out of the injectors. I am not getting a check engine light kicked on and it has been hooked back up on the computer at the shop and no codes are being kicked back.
I am really at a loss at this point. I am getting this computer replaced today just in case it is a computer issue seeing how the Blazer started up and ran as soon as I put the first new computer in. I have heard a couple say the proms (chips) were known to go bad. I am not sure if this is my issue or not.
I just cannot figure out what is going on since I am not getting any codes what so ever.
have the same problem?
Thursday, January 21st, 2010 AT 3:38 PM