Sometimes when I start my car the RPM's will jump way up and down for a few seconds amd finally will settle down and it also has been taking a few tries to start.
Some say it may be a vacuum leak. Is the best way to check for a vacuum leak like the way Haynes manual says or is there something better?


Sometimes on the first try the car actually won't start and it acts like it I has a dead battery(weak sound from the starter and dim lights) but the next try it will start.

I just changed the starter today so that isn't it.

This is what I plan on checking:
1) Camshaft Position Sensor(POS)
2) Ignition switch
3) Fuel Pressure
4) Vacuum Leak

Could there be anything else that could be causing me problems.
Please help!!


1995 w 118,000 mi.

 

Bump,Bump,Bump

 

Hate to do this again but, does anyone know how to check for vacuum leaks.

 

IACV...upstream on the back of the intake manifold...take it off with three bolts and clean it with throttle body cleaner..should fix the problem

-matt

 

I cleaned it about 10,000 miles ago. Can an IACV go bad or does it just get dirty?

 

It could go bad..I replaced mine with a 98 Unit and it still drops off sometimes when I bring my car down to idle lets say at a stoplight...

-matt

 

Well I just cleaned the IACV agin and checked the vacuum and nothing has changed.
The IACV was still pretty clean and the vacuum pressure stayed steady at 19-20psi which is normal according to Haynes manual.
Any other suggestions? Has any one ever checked their fuel pressure?

 

this may not be such a good idea but has worked many times for me ( i actually found a leak on the bottom side of an intake manifold once) but just use propane, like the handheld ones for plumbing. DONT light it, just let the gas run out and move it around the engine bay while its running. you might be able to use like wd-40 or something too...but if and when you find one the engine will sputter (and maybe die). Again, this isnt the best of ideas but it does work if you have the *****.

 

That's the worst idea I've ever heard. Use the method outlined in the Haynes manual to check vacuum pressure.

-Ace-