Ok, this is my first post on the forum. I am working on my friends 97 GTS and he keeps getting a low MAP sensor voltage code. The map sensor was already changed at a dodge dealer however I believe the reason he is getting the code is the engine is pulling 10 to 11 inches of vacuum at idle and loading up with fuel. I searched for a vacuum leak around the intake and did a compression check. The cylinders all came up around 160 to 170 psi. I turned out the throttle stops to try and raise the idle just a little even though I know the idle would be brought back down with the IAC. Has any one ever had this kind of problem.
I would not start turning the screws on a car you have limited experience with. What exactly is the obd2 code that is being thrown. Is this vehicle stock or modified, and if modified please list what is done.
[quote=v10kingsnake]I would not start turning the screws on a car you have limited experience with. QUOTE]
What he said! Those vacuum numbers are fine for the V10 as is the compression. Looks to me like this is going to be wiring or PCM related. You need to see what MAP sensor voltage the PCM is actually seeing. If it is a random fault code, look to the wiring harness under the booster. It does not appear to be mechanical and if it was loading up at idle you would have fault codes for both front oxygen sensors at their correction limits (or a rich code, however you want to say it). Since you moved the throttle blades, you now need to resynch the throttle bodies. Good luck, DW
Ok, this is my first post on the forum. I am working on my friends 97 GTS and he keeps getting a low MAP sensor voltage code. The map sensor was already changed at a dodge dealer however I believe the reason he is getting the code is the engine is pulling 10 to 11 inches of vacuum at idle and loading up with fuel. I searched for a vacuum leak around the intake and did a compression check. The cylinders all came up around 160 to 170 psi. I turned out the throttle stops to try and raise the idle just a little even though I know the idle would be brought back down with the IAC. Has any one ever had this kind of problem.
Vacuum is 1-2" too low.
Compression appears about 10# too low.
You screwed up by messing with the throttle stops.
Ok, this is my first post on the forum. I am working on my friends 97 GTS and he keeps getting a low MAP sensor voltage code. The map sensor was already changed at a dodge dealer however I believe the reason he is getting the code is the engine is pulling 10 to 11 inches of vacuum at idle and loading up with fuel. I searched for a vacuum leak around the intake and did a compression check. The cylinders all came up around 160 to 170 psi. I turned out the throttle stops to try and raise the idle just a little even though I know the idle would be brought back down with the IAC. Has any one ever had this kind of problem.
your best bet is to put that car on a scanner, where you can read all the parameters. I would check your coolant temp sensor { make sure it's not at a neg. number,} and also look at what your map sensor is doing. when you said you did a comp. test, how did you do it? with the trottle open, or closed? anyways, good luck.
I am getting a " map sensor voltage to low" code. I am using a Snapon MT2500 scanner with the appropriate card and key. I checked the wiring and the vacuum gauge and the scanner are reading the same so I don't think it's the map sensor it's self unless the dealer installed the wrong map sensor. I only turned out the throttle stoppes 1/4 turn and have since turned them back. I also hooked the same vacuum gauge up to my 97 RT/10 exact same motor and factory cam and the vacuum reading was the same. The GTS is bone stock. I will check again but when I had the scanner hooked up to the car there were no other codes and all the sensors were reading fine. When I did the compression check I did it with all the spark plugs out and the throttle bodies open. Is there any thing else that I should try?
I am getting a " map sensor voltage to low" code. I am using a Snapon MT2500 scanner with the appropriate card and key. I checked the wiring and the vacuum gauge and the scanner are reading the same so I don't think it's the map sensor it's self unless the dealer installed the wrong map sensor. I only turned out the throttle stoppes 1/4 turn and have since turned them back. I also hooked the same vacuum gauge up to my 97 RT/10 exact same motor and factory cam and the vacuum reading was the same. The GTS is bone stock. I will check again but when I had the scanner hooked up to the car there were no other codes and all the sensors were reading fine. When I did the compression check I did it with all the spark plugs out and the throttle bodies open. Is there any thing else that I should try?
well, if you think the map sensor is not the right one. pull the one off your car and try it out! see if it makes a difference....
Ok, this is my first post on the forum. I am working on my friends 97 GTS and he keeps getting a low MAP sensor voltage code. The map sensor was already changed at a dodge dealer however I believe the reason he is getting the code is the engine is pulling 10 to 11 inches of vacuum at idle and loading up with fuel. I searched for a vacuum leak around the intake and did a compression check. The cylinders all came up around 160 to 170 psi. I turned out the throttle stops to try and raise the idle just a little even though I know the idle would be brought back down with the IAC. Has any one ever had this kind of problem.
Is this vacuum reading from the map sensor port?If not,check it at that port.GoodLuck!
The compression is right where it should be. You should let it turn over 8 revolutions with the throttle open.
In my opinion, the vacuum is low, a stock viper should be 15-17 in. When I had a bad intake gasket, the vacuum dropped to 12 in, it now runs at 16 and this a 97 with the lumpy cam. The obvious places for a vacuum leak on a Gen 2 are:
1. Intake manifold.
2. Brake booster connections.
3. IAM
4. Heater control vacuum pickup (rear passenger side)
5. Crankcase evacuation hoses (front of intake)
6. Manifold vacuum sensor.
Linear Mode
