Manager Forum

HAVE 2001 DODGE P/U 1500; CAME IN FOR A MISS & ROUGH IDLE. CHANGED PLUGS, WIRES, CAP, ROTOR, CLEANED INJECTORS.

STILL HAS ROUGH IDLE?

What are your fuel trims?

-1.7 to 6.6

pull pcv out and plug port in valve cover. take off oil cap and place hand over the port and see if you feel any suction. look through the throttle body and see if there is any sign of oil contamination on the lower plate. if this is the engine i'm thinking of there were huge issues with the plate gasket blowing out and causing a vacuum leak and rough idle. you could hook up a vacuum gauge and check that way but i use the good old hand over oil fill method, it's quicker. if it' appears to be the gasket issue get the repair kit from the DEALER. it comes with a replacement plate. a few more bucks but well worth the small investment. i tried just replacing the gasket from a gasket set purchased from my local parts supplier (without the plate) and i couldn't get it to set to my satisfaction, it kept popping out at the sides. whew...........i wish i could refine my posts.

thanks i will try that

THERE WAS NO SUCTION,BUT CLEANED THROTTLE BODY . IT HELP SOME ,BUT DID NOT FIX. MORE HELP WOULD BE GREATLY APPERICATED

Are you seeing missfires on the missfire data on your scanner?

Is it just at idle? I have seen bunches of those engines that have the inlet screen on the injectors pluged with really fine dirt/dust/rust. Have to pull the injectors and look at the inlet and then what I do is put the injectors in an old fuel rail I keep laying around and pulse the injectors with gas hooked up to the rail, this reverse flushes the injector and removed the offending trash. I have used carb spray with the straw and blow the trash out that way before I started reverse flushing them.

YES THANKS ILL TRY THAT

SORRY THERE IS NO MISFIRES

a couple of quickies here. is there any evap solenoids stuck open? try plugging off all vac ports including brake booster. if issue resolves itself start attaching one at a time to isolate. if problem persists try introducing propane into the air intake or spray carb cleaner over the intake opening. not directly into it and see if idle smooths out. this is going to be a process of elimination........

already tryed both of those things

Is the EGR stuck open a little?

no

haven't heard anything about compression.......i've seen bent push rods cause this..

compresson is good

after futher test ended up begin intake gasket. thanks for all the help

If the intake gaskets were leaking shouldn't the fuel trims have showed a possible vaccum leak? Thats weird if they did not. Guess i just have not ran into that before.

brianp87 wrote:If the intake gaskets were leaking shouldn't the fuel trims have showed a possible vaccum leak? Thats weird if they did not. Guess i just have not ran into that before.

i've hit a few where the trims weren't that far out. the leak is so close to the intake port that it can be a very, very, small leak. these trucks run a bit on the rich side any way. as a rule when any of this "vintage" come into my shop with a rough idle the intake is yanked off and the plate replaced. glad the issue was resolved and thanks for the fix being posted.......

yes its good to know if I run into it