No Fuel Injector Pulse
#1
03-26-2008, 11:28 PM
No Fuel Injector Pulse
Hi guys,
My girlfriend has 98 Blazer 4.3l with 138k miles. She is a broke college student and i am trying to help her out.The fuel pump was replaced 6 weeks ago with a Napa fuel pump.Shortlyafterwards while driving the car it started to stumble like it wasn't getting gas. I happened to be in the car and thought it wasthefuel pump again. It happens. Within a mile it died. I checked the fuel pressure by sticking my finger in fuel pressure check valve behind the throttle body. Almost no fuel came out. So i figured the fuel pump was bad and we had it towed to the garage that replaced the fuel pump.
The mechanic put direct power from the battery to the fuel pump and the fuelpump runs fine. The mechanic told me when he hooked up his diagonsiccomputerthat hewas only able to read simple codes. He said there is a short somewhere in the electrical system that isn't allowing the ECM to recieve information. He said he didn'tknow what the problemwas and offered to buy her car for $300.
Later that day the mechanic called me back and said he did some further testing and the problem is a short causing no fuel injector pulse.
Two days later he called her and offered her $400 for the blazer. Finally, he told me that he knew what the problem was. He said, "The problem is a short behind the dash, and it would cost $800 to fix." I asked him what the problem was? The mechanic said he couldn't tell me that. I said why. He said, "This is about $$$,this is a business, and he isn't going to reveal any information."
Do you guys know what the problem is? A short behind/under the dash that will not allow fuel injector pulse?
Your thoughts are appreciated.
Allan & Kari
My girlfriend has 98 Blazer 4.3l with 138k miles. She is a broke college student and i am trying to help her out.The fuel pump was replaced 6 weeks ago with a Napa fuel pump.Shortlyafterwards while driving the car it started to stumble like it wasn't getting gas. I happened to be in the car and thought it wasthefuel pump again. It happens. Within a mile it died. I checked the fuel pressure by sticking my finger in fuel pressure check valve behind the throttle body. Almost no fuel came out. So i figured the fuel pump was bad and we had it towed to the garage that replaced the fuel pump.
The mechanic put direct power from the battery to the fuel pump and the fuelpump runs fine. The mechanic told me when he hooked up his diagonsiccomputerthat hewas only able to read simple codes. He said there is a short somewhere in the electrical system that isn't allowing the ECM to recieve information. He said he didn'tknow what the problemwas and offered to buy her car for $300.
Later that day the mechanic called me back and said he did some further testing and the problem is a short causing no fuel injector pulse.
Two days later he called her and offered her $400 for the blazer. Finally, he told me that he knew what the problem was. He said, "The problem is a short behind the dash, and it would cost $800 to fix." I asked him what the problem was? The mechanic said he couldn't tell me that. I said why. He said, "This is about $$$,this is a business, and he isn't going to reveal any information."
Do you guys know what the problem is? A short behind/under the dash that will not allow fuel injector pulse?
Your thoughts are appreciated.
Allan & Kari
#2
03-26-2008, 11:37 PM
RE: No Fuel Injector Pulse
Sounds like he's trying to rip you off. I would get out of there as soon as you can.
If you don't have fuel pressure under normal circumstances, but when the pump is jumpered you have appropriate pressure (did he show you the truck run when the pump was jumpered?), then you have three possibilities. #1 - blown fuse. #2 - faulty relay. #3 - wiring fault. I would start by checking the fuse and relay. I would next check the ground and power at the pump.
Now, if you find that the relay and the fuse are good and there is no +12V getting to the fuel pump with initial key on, then it is possible that the PCM isn't triggering the fuel pump relay, but lets cross that bridge when we need to.
How much of the investigation can you do yourself?
Notice that none of those involve anything wrong with the injector pulse. He's throwing terminology in incorrect context at you in hopes that you will bite. The fuel pump has nothing to do with fuel injector pulse.
*Moving to 2nd Gen Tech*
If you don't have fuel pressure under normal circumstances, but when the pump is jumpered you have appropriate pressure (did he show you the truck run when the pump was jumpered?), then you have three possibilities. #1 - blown fuse. #2 - faulty relay. #3 - wiring fault. I would start by checking the fuse and relay. I would next check the ground and power at the pump.
Now, if you find that the relay and the fuse are good and there is no +12V getting to the fuel pump with initial key on, then it is possible that the PCM isn't triggering the fuel pump relay, but lets cross that bridge when we need to.
How much of the investigation can you do yourself?
Notice that none of those involve anything wrong with the injector pulse. He's throwing terminology in incorrect context at you in hopes that you will bite. The fuel pump has nothing to do with fuel injector pulse.
*Moving to 2nd Gen Tech*
#3
03-27-2008, 06:21 AM
RE: No Fuel Injector Pulse
Sounds like Mr. Mechanic has been in the market for a Blazer, and I think he's found one he likes
. Definitely go to another garage. If you explain the situation to the new garage, say you know you're getting ripped off using Kyle's points above, the new garage will probably be inclined to tow the Blazer to their place free of charge (granted they will now be doing the work).
Good luck!
. Definitely go to another garage. If you explain the situation to the new garage, say you know you're getting ripped off using Kyle's points above, the new garage will probably be inclined to tow the Blazer to their place free of charge (granted they will now be doing the work).Good luck!
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