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Poor Gas mileage & Loss of Power "Solved"
#21
05-28-2009, 09:14 PM
Although I don't have a 2nd gen, since we're on the topic of MAP sensors, I went out and tested mine this evening. It read fine with the motor off, but with the motor idling, it was at ~1.12V. When I kicked it up to WOT, it peaked at ~4.35V, and when it was dropping back to idle, it was reading ~0.15V (although it drops fast, so that was a hard one to check). These aren't horrible readings, but they are at the very low side of the accepted range. What do you guys think, replace it or leave it?
I should also mention, the reason I checked it in the first place is cause my truck has a hard time coming back down to idle when I depress the clutch. It will try to stall and then "catch" itself. I have already replaced the IAC. It's been like this ever since I did the auto to manual transmission swap.
I should also mention, the reason I checked it in the first place is cause my truck has a hard time coming back down to idle when I depress the clutch. It will try to stall and then "catch" itself. I have already replaced the IAC. It's been like this ever since I did the auto to manual transmission swap.
I found out how important that sensor really is to the drivability and characteristics of any car with a map sensor. I bet a lot of the dodge trucks with idle issues has to do with the map sensor as well.
#22
05-28-2009, 09:30 PM
Although I don't have a 2nd gen, since we're on the topic of MAP sensors, I went out and tested mine this evening. It read fine with the motor off, but with the motor idling, it was at ~1.12V. When I kicked it up to WOT, it peaked at ~4.35V, and when it was dropping back to idle, it was reading ~0.15V (although it drops fast, so that was a hard one to check). These aren't horrible readings, but they are at the very low side of the accepted range. What do you guys think, replace it or leave it?
I should also mention, the reason I checked it in the first place is cause my truck has a hard time coming back down to idle when I depress the clutch. It will try to stall and then "catch" itself. I have already replaced the IAC. It's been like this ever since I did the auto to manual transmission swap.
I should also mention, the reason I checked it in the first place is cause my truck has a hard time coming back down to idle when I depress the clutch. It will try to stall and then "catch" itself. I have already replaced the IAC. It's been like this ever since I did the auto to manual transmission swap.
personally, i wouldnt worry about it too much.. goin from idle to WOT gradually, i was fluctuating badly between .8 volts to 1.7 volts. the fluctions were more like spikes, and they varied between rpms. say i was at 1800 and it was .9, then at 2400 rpms i was at 1.2, then back down and up, it's shot. however from what you told me and compared it to the chilton manual, youre within spec. test in while to makesure it hasnt crapped out on ya
#23
05-28-2009, 09:48 PM
Mine was doing the same thing if I gradually increased. I think the reason for that is cause there's not much of a vacuum as you gradually increase in rpms, but if you grab the throttle lever on the side of the throttle body and shove it open all at once it should pull a huge vacuum as it's trying to suck in a whole lot of air, and thats where mine was peaking at ~4.35V.
#24
05-28-2009, 10:31 PM
Mine was doing the same thing if I gradually increased. I think the reason for that is cause there's not much of a vacuum as you gradually increase in rpms, but if you grab the throttle lever on the side of the throttle body and shove it open all at once it should pull a huge vacuum as it's trying to suck in a whole lot of air, and thats where mine was peaking at ~4.35V.
#25
05-28-2009, 10:42 PM
Lol, I can't really hold mine at WOT, cause I have a mopar performance computer in my truck that eliminates the rev limiter. I really don't want to blow the engine up (at least not until the 408 is done and ready to swap :P). So I wasn't able to tell if it builds vacuum or not at WOT when you gradually rev it WOT, but I think it was acting like your's. I think I might just go ahead and replace the MAP sensor if for no other reason than it's 14 years old and it just might help solve my idling issues.
#26
05-29-2009, 12:42 AM
Lol, I can't really hold mine at WOT, cause I have a mopar performance computer in my truck that eliminates the rev limiter. I really don't want to blow the engine up (at least not until the 408 is done and ready to swap :P). So I wasn't able to tell if it builds vacuum or not at WOT when you gradually rev it WOT, but I think it was acting like your's. I think I might just go ahead and replace the MAP sensor if for no other reason than it's 14 years old and it just might help solve my idling issues.
It might be in tolerance, however, is that at each voltage point? You can't monitor that unless your on a dyno. Then you will need a tuning solution to see where each point is hitting on the fuel map.
It's best just to change it out. You will be happy with the result. You can't beat $66 at autozone.
#28
05-29-2009, 11:29 PM