I have a 94 Ram 1500 318 CID motor. It is all stock. I think the vapour emissions is the problem. At the moment I am getting about 6 - 7 miles to the gallon. 2 months ago it built up pressure in the fuel tank an it done about 14- 15 miles to the gallon. Anyone know where might be the best place to start. I have checked the ECM and there is no trouble codes stored on it to do with the motor or emission system. Thanks for any help or ideas in advance.

 

when is the last time you did some plugs and wires and wir filter? start simple

 

.....air*

 

It got bosch platium +2 plugs and wires 5000 miles ago. New air filter 4 months ago and its clean, and the following new parts- air charge sensor, igination coil, PCV, crank position sensor, cat converter, EGR, oxygen sensor . I have a new cap, rotor and cam position sensor but I can not put them on because the old cap screws are rusted and the only way they might open will be to break off the old cap then grip the screws with a vice grip. Is it possible to get the distrubitor out of the block with out having to take the motor out ther truck. Some times when I tap on the gas at idle the motor stalls or almost stalls. With the transmission in park if I floor the gas the motor sounds like its flooding or getting to much gas at the low revs. I got trouble with vaccum lines blocked before but I have checked out these and are ok.

 

This might be of some help to you https://dodgeforum.com/forum/1928466-post12.html

 

Thanks for that link will try that some day.

 

6-7 is really bad. are you sure you're not losing gas to a leak ?

i wouldn't think that the evap system could hurt your mileage. its just vents vapors into the intake, so even if it malfunctioned and stayed open, it would be lean and just a big vac leak.

do you have black smoke and/or rich smell to the exhaust. you might have a faulty front 02 sensor making everything rich. or you might have a single leaking injector. check plugs for any fouling on a single plug.

check for smell of gas to indicate a leaking tank or gas line.

you said you didn't have any engine codes. do you have any codes ?

 

try unplugging your o2 sensors, do the front and if it dont run better plug it back in and do the back, if that dont work get your injectors cleaned out

 

Ok guys. let's all chime in together.....a 1.....a 2........plenum gasket!

 

unless the plenum oil has fouled the 02 sensor, i doubt the plenum is his immediate problem. when my plenum was leaking the truck was a slug and pinged and used oil, but my mpg was normal.