I have a 1990 f150 4.9l 4x4 automatic. I have been having troubles lately. When I cold start the truck it usually dies the first and sometimes second time but then starts right up. It also dies or almost dies when I first ease on the gas. Sometimes it seems like it is going to die when accelerating from a stop but then i press harder on the pedal and its fine. If I stop somewhere, when I come back out and start it, it has no problems usually. My engine light is on and is showing code 22 which i found meant: MAP (vacuum) or BARO signal out of range - MAP. I have only started working on my own vehicles since I got this truck less than a year ago so any help is appreciated. My mpg is right around 10 which seems a little low but I mostly just drive city miles to work which is only like 3 miles away.

 

Test and/or replace map. Your truck is a 1990 it don`t have baro. Pull engine vac also.

 

I replaced the map last September, how would I test it? Is there something that could be causing it to go bad? Also not sure about pulling the engine vac.

 

It has one hose going to the map. Take it off and blow and suck on it. Does it leak? Engine vac is measured with a vacuum gauge off the brake booster hose when the truck is at idle.

 

https://www.f150forum.com/attachment...1&d=1368040147

You have to do is right or the results of the test does no good. Disconnect the connection and measure the volts on the vfer it should be 4-6 volts. This is with koeo. Let me know what you get. And if this is not what your connection looks like.

 

Awesome Ill go get a voltometer from advance auto and Ill check it out. Just found out my tranny is leaking so I have to look into that first.

 

Your also going to need a hand vac pump with a gauge to finish testing the map. Checking the vref is just the beginning of the test.

 

When you buy the meter make sure it can do hurz also.

 

Ok thanks I appreciate the help