Blew something...help!

[DTT92LX]

Hey,

Punched it yesterday and must've blown out something but can't figger it out...

Car is running really rough. At idle, in park, warm start, it revs at ~750 for 1 sec, then stumbles for 1 sec and keeps cycling that way. During the "stumble" period, I hear a hissing under the hood. Sounds like under the upper intake but can't really tell from where. Also, exhaust smells REALLY rich.

When driving, it sounds fine, haven't really pushed it to test for power loss.

any ideas guys?

 

[DTT92LX]

Was just out listening to the hiss and it is definitely coming from under the upper intake. What is that tube that I can see from the front of the car that goes from the intake around back to head/block/somewhere?

 

[shttygtstang]

head gasket ????? do a compession test theres not much to go buy

 

[DTT92LX]

That was my initial thought but saw on here that you should see bubbles in the radiator on a cold start if head gasket. Don't know how reliable that test is though...

Anyone know what that tube is?

 

[Js5ohLX]

Sounds to me like a vacuum line fell off or cracked.

 

[Quick5pnt0]

Sounds to me like a vacuum line fell off or cracked.

I agree, you have to go out start the car and try to listen where the hissing is coming from. Its probably just a vaccum line that came off under the intake or something.

 

[Daggar]

You can start by running the engine then spraying some starting fluid around that area to see if the engine idles up. So long as everything is tight (meaning your throttle body out to your air cleaner etc.) then hearing the engine idle up is a sure indication that something is sucking that starting fluid in. If you don't get any change in the engine pitch (meaning that you don't have a vacume leak) then change your throttle position sensor. In that case, the sucking noise you hear is the motor trying to spin up and the throttle body not opening quick enough to keep up with it. You can also check this by disconnecting the intake hose from the throttle body then revving up with the throttle linkage. If you hear air being "sucked" past that throttle body then that's a pretty good indication that the sensor is whacked. That condition would also explain the rich fuel smell you're getting.

 

[Whytry91]

off topic, but I saw he was a new guy so I thought I'd spruce up his avatar.

 

[Daggar]

hehehe... thanks... now is he not only a mindless killer, he's phsycho! lol

 

[88mustangGT]

defently a vacume hose poped off or cracked. it will cause you to run rich when that happens.

 

[DTT92LX]

Just to tie up this thread...

Once the engine cooled off a bit I got my meaty paw up under the intake and found the vacuum leak. The hose on the left split at the nozzle. Its not the hose going around back the engine but the other, smaller, one going down to a box under the airbox. WOT module I think I've heard it called???

Thanks for the help.

 

[89lxsport50]

The small hose on the front of the intake goes to your charcoal cannister. The large one that goes around back is the PCV hose.

 

[DTT92LX]

What's the charcoal canister do? Can it get clogged, 'cause now that I reattached the hose, a very old hose mind you, it's collapsing slightly under the vacuum. Up at the intake end. I'll put a new hose on but I'm just wonderin' if I have other problems that I should consider... Don't think the hose should really collapse unless there's blockage at the canister end...