Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
Here is a little back story, New motor, new everything sensors and all. At idle it runs rough like it has a bad ass cam. It’s does not have a misfire. I tested the MAP and it tricked me at first just like in chapter 8 Paul said it would 2.5 on signal. But I can unplug it and it runs perfect…. I’m going to check the voltage the right way tomorrow but what else could be bad that unplugging the map could fix if it’s not the map?????
I have a 1988 F-250 that doesn't respond to the voltage test. I think it is measured in ohms. I could be wrong but thought it might point you in the right direction if voltage test comes up empty. Mine runs perfect with alternator unplugged, go figure.
Sounds like possibly a vacuum leak to me.
That's exactly a friend of mine described his 5.0 when it had a vacuum leak (sounds like it has a bad ass cam!)
Okay get this! It’s the first for me but there is to much vacuum! 21 pounds and it runs great when I put 10 pounds on it. How can I lower the vacuum without a leak?
It's relying on the tps when map is unplugged, so check tps first, then smack map with a hammer, then replace, lol, have to ask this, any old sensors still in possession?
