ajbremer
New member
MAP Sensor problem fixed
I bought my 1991 Pontiac Sunbird 2.0L for $400 just the other day. Gave a guy at work $200 on pay check and $200 the next. Great looking car, no dents, cold air, good heat, white in color, and it's a convertible!
Any way, his story is this. He's replaced many hundreds of dollars worth of parts and still couldn't fix his problem. He said the car will run fine for a few days and then spit, sputter, and stall to the point of thinking that you'll be stranded on the side of the road. When it ran bad, he said he would park it for weeks, get in it again, and then it would run ok for a couple of days and then the same problems would return.
He's taken it to two mechanics who didn't end up fixing the problem, he replaced the starter, coil, computer, O2 sensor, MAP sensor, plugs, plug wires, fuel pump in the tank, fuel filters, and the list goes on. But yet the car would continue to have major problems. Then one day not too long ago, the water pump started to leak and at that's the point where he decided to sell it to me because he said he's put too much money into it and that's the end of that!
Well, I changed the water pump and a few gaskets and put it all back together and the same problem came up. It ran ok for a few miles and then it would spit, sputter, and stall. You'd be going down the road around 15 or 20 mph and it acted like the fuel was being turned off and then on again every 5 seconds. It woud go and then it would want to stall, I'd step on it and then it would go again, then try to stall, back and forth. So...here's what I did.
I put a jump wire onto the diagnostic port to find my codes because the engine light was on. It gave me a code 34 (MAP Sensor). The guy that sold me the car said he put a new MAP sensor on it so I started into looking at it. It has a vacuum line and 3 wires going to it. Well, I started the car and then I began to tap on the top of the sensor and it would change the idle now and then, you could tell by the sound. When I removed the vacuum line I could feel vacuum in the line so I thought that was a good sign.
Then I began to look at the sensors jack/plug and the 3 wires that go into a bunch of other wires after about 10 inches of length. Some of the wires looked squeezed, crushed, and bruised. So I decided to do a continuity check. I bared the wires down really low just about where they go into the other wire bunch. Then I used a continuity checker, one end on the bare spot and the other end touching the little prongs within the plug. I found it was all good, even when I moved all the wires around the continuity was good...good connections there.
I plugged it all back in and drove it to church. It drove ok until we were on our way back home and then the problem started again. I just about couldn't keep the car running. I pulled into a gas station to try to mess with it again and then an idea came to me.
Those prongs inside the jack/plug (3 wires) seemed kind of skinny and maybe one of them wasn't making connection into the female parts of the MAP sensor. So I got into my tool box and found some thick wire. I cut off 3 single strands about 1/8" long and set them down into each one of the 3 tubes of the MAP sensor, using them like an electrical shim. I plugged the jack into the MAP sensor and the car runs great!
I've driven it a couple hundred miles since then and there's been no problems at all. Has anyone else ever heard of this happening before? Thanks!!!
I bought my 1991 Pontiac Sunbird 2.0L for $400 just the other day. Gave a guy at work $200 on pay check and $200 the next. Great looking car, no dents, cold air, good heat, white in color, and it's a convertible!
Any way, his story is this. He's replaced many hundreds of dollars worth of parts and still couldn't fix his problem. He said the car will run fine for a few days and then spit, sputter, and stall to the point of thinking that you'll be stranded on the side of the road. When it ran bad, he said he would park it for weeks, get in it again, and then it would run ok for a couple of days and then the same problems would return.
He's taken it to two mechanics who didn't end up fixing the problem, he replaced the starter, coil, computer, O2 sensor, MAP sensor, plugs, plug wires, fuel pump in the tank, fuel filters, and the list goes on. But yet the car would continue to have major problems. Then one day not too long ago, the water pump started to leak and at that's the point where he decided to sell it to me because he said he's put too much money into it and that's the end of that!
Well, I changed the water pump and a few gaskets and put it all back together and the same problem came up. It ran ok for a few miles and then it would spit, sputter, and stall. You'd be going down the road around 15 or 20 mph and it acted like the fuel was being turned off and then on again every 5 seconds. It woud go and then it would want to stall, I'd step on it and then it would go again, then try to stall, back and forth. So...here's what I did.
I put a jump wire onto the diagnostic port to find my codes because the engine light was on. It gave me a code 34 (MAP Sensor). The guy that sold me the car said he put a new MAP sensor on it so I started into looking at it. It has a vacuum line and 3 wires going to it. Well, I started the car and then I began to tap on the top of the sensor and it would change the idle now and then, you could tell by the sound. When I removed the vacuum line I could feel vacuum in the line so I thought that was a good sign.
Then I began to look at the sensors jack/plug and the 3 wires that go into a bunch of other wires after about 10 inches of length. Some of the wires looked squeezed, crushed, and bruised. So I decided to do a continuity check. I bared the wires down really low just about where they go into the other wire bunch. Then I used a continuity checker, one end on the bare spot and the other end touching the little prongs within the plug. I found it was all good, even when I moved all the wires around the continuity was good...good connections there.
I plugged it all back in and drove it to church. It drove ok until we were on our way back home and then the problem started again. I just about couldn't keep the car running. I pulled into a gas station to try to mess with it again and then an idea came to me.
Those prongs inside the jack/plug (3 wires) seemed kind of skinny and maybe one of them wasn't making connection into the female parts of the MAP sensor. So I got into my tool box and found some thick wire. I cut off 3 single strands about 1/8" long and set them down into each one of the 3 tubes of the MAP sensor, using them like an electrical shim. I plugged the jack into the MAP sensor and the car runs great!
I've driven it a couple hundred miles since then and there's been no problems at all. Has anyone else ever heard of this happening before? Thanks!!!
