I know you have Speed Density...MAP = Manifold Absolute Pressure sensor. It's located on the passenger side of the engine bay on the upper firewall.

For reference:


No, I do not believe the vacuum lines are in very good condition. 20+ years of heat take their toll.

That's one way to do, although not my preferred method.

Here is another:


I went real cheap a few months ago and used my shop vac setup in "blow mode". I placed a smoldering cigar inside...it works like a charm.

 

Oh ok sorry about that lol do u think maybe the map sensor could be bad? And yeah ill probably do the smoke test tonight.

 

Did you get a code for the MAP sensor?

 

No i was just wondering if it sounded like a bad map sensor to you cuz im not sure what a map sensor does lol

 

Well im still trying to get around to do the smoke test.... Here is a link to a video. My truck is making a rattling sound or bad pulley sound. Sounds like the passenger side rear of the engine... What coukd i check cuz i can find anything.

https://youtu.be/pw83EBQlE78

 

have you checked your timing that will affect idle and how she runs?

 

No i have no way of checking.


Better link

 

Anyone have any thoughts?

 

No idea...could be an idler pulley, alternator bearing, water pump, air pump, etc.

Take off the belt then spin each accesory and pulley by hand then listen.

 

I did a couple days ago the only thing i noticed was the ac compressor making that horrible grinding sound.. I put a metal rod against everything that could be making that sound but cant find anything yet. Ill try again tomorrow. Still trying to find time to do the smoke test.

 

So.... Still havent done the test but. If the tough idle has nothing to emissions, ignition, or fuel. Then doesnt that just leave timing (i doubt is it) and vacuum leak in intake manifold?

 

Also what is the most efficient test other than the smoke test... Ive seen the propane and have dont the throttle body cleaner test..... But no

 

Rough idle has everything to do with ignition and fuel as well as accurately metered air (vacuum leaks). Add in equal compression in each cylinder. It's a big recipe to decipher.

 

I have never been a fan of propane or carb. cleaner spray to find vacuum leaks. Others have their opinions.

 

Well i mean fuel and ignition have check out to be fine lol i dont smoke and no one i know does so its hard to do the smoke test.

But u said its common for the intake manifold gasket to go bad right?