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brownjeff, ASE Certified Technician
Category: Dodge
Satisfied Customers: 13886
Experience:  17 years experience, ASE certified, dealership certified, Service Manager for 15 years,
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i have a 96 dodge ram 1500 4x4 i believe i got a vacuum leak

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i have a 96 dodge ram 1500 4x4 i believe i got a vacuum leak but tracing it is very hard... i run rich, i lose gas, possible misfire on cyl. number 5, checked the routing of wires they are now correct did a tune up (complete), i lose vacuum going on inclines during steady and moderate accelerator pedal pressure, replaced all check valves...what could i be missing?
Have you tried pinching off the vacuum lines one at a time to see if you can locate the leak? Have you tried spraying carb cleaner or throttle body cleaner around the intake area to try and locate a vacuum leak?
Customer: replied 7 years ago.
yes i have sprayed around the manifold and all vacuum lines i did get an increased rpm around the throttle body at the map sensor however i got mixed results around the intake and also i just learned on my truck that the front axle is automatic and is vacuumed operated i knew that but what i didnt know the extent to which they were routed... now my truck does have some rust issues.... what i am trying to figure out is to why i have such bad performance even though i cant really find the source... so here is my delima i am a technician ASE certified but i dont have the feild experience to pinpoint certain problems... now i did have the manifold removed at some point to seal the oil leaks form the top... but didnt have a problem til later down the road....i had the fuel system repaired and sealed all fuel leaks... now i do have a leaking block freeze plug but i cant get to it though at the same time i add coolant to the system everey once and a while.... now i noticed if i drive with the 4th gear disabled basically O/D Off i do not lose vacuum on hills.... i also noted that the vacuum lines go to the top of the trany/transfer case... i sprayed in that area as best as i can, however i ran into the same results no increased rpm.... is there something i over looked is there anything i havent done.... i am almost at wits end trying to figure this drivabillity problem for the past year of owning this vehicle so what else is there?
Do you get any codes in the computer?
Customer: replied 7 years ago.
no codes i even took a scan tool and recorded data found no anomilies except for the ignition advance degrees... this has sparked an intrest but do not know why though it reads during the test drive between fram 0 to frame 80 a total of 30mins of data i found the lowest it went was 10 degrees the highest it went was 25 degrees... i was also looking at fuel trim short and longterm.... those two started out in great numbers but during the final mins it was to me reading normal at like +-5% so it does switch around and for that i know my fuel meter sensor front O2 sensor is functioning properly but i cant really figure out as to why i smell gas in the tail pipe... though the ignition timing is a little red flag to me.... i once had an isuzu amigo carburated and distributor driven i advanced the timing manually by turning the distributor and it caused all sorts of problems so i wonder if i need to do something to the distributor...
The timing is not adjustable and is controlled by the computer so unlikely causing the problem.

Have you cleaned the throttle body and the injectors as many times these are over looked and can cause many driveability problems
Customer: replied 7 years ago.
yes the throttle has been cleaned and so has the injectors... maybe its time to take it to a shop i have done every thing i can do and i dont know what more there is if you and i have done all these things and still no results as to fixing the problem what else is there??? i have done everything you asked and i dont know what it could be... could it be internal that the only other way of testing is cylinder compression and leak test is that all that is left i mean they have tested fine in the past i still dont know why i am still having these problems.
That was going to be my next suggestion to check compression if you have not already to make sure mechanically everything is good.
Customer: replied 7 years ago.
now i know the last test date it was with in the past 2mos.... i will try it again but i dont know... maybe if i tell you i have a hesitation when cold or from a stop and when pulling off the gas goes down... it doesnt however do it again once driven for a while... what if that could be the problem.... maybe i have good compression but warped cylinder walls i dont see that likely but now it may be a factor i know the oil pump went out and had it replaced.... could it be oil or block related.... i do hear some ticking but from past advices that was normal.... my engine does rock and tumble like it is power balancing so where might this peice of the puzzle fit in?
If the oil pump has failed in the past then I would definitely do a compression test to make sure mechanically the engine is good as if it lacked oil at any time could have caused a mechanical problem
Customer: replied 7 years ago.
the oil pump went out in october of last year since then i have had numerous compression tests either for beliefs that i have and actually do have a blown head gasket or because it was warrented do to the nature of the jobs being done to the vehicle like i have said tests have been good since october of last year.... if this is all we have then i dont know... if you have any other theories or hypotheticals as to what i have and havent done please tell me like i have said i have tried everything i am wits end. so maybe that mixed results at the intake is the problem but if there is no other then the vehicle is beyond both yours and my knowledge.... so what else havent i done???
Remove the distributor cap and try moving the rotor back and forth by hand. If there is excessive play in the distributor it will effect the timing and cause the vehicle not to run correctly
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