Intake gasket leak?

[MJ'sBlkBII]

I have been having a very high idle (between 1200-1800 rpm), a lot of smoke/steam and condensation from tail pipe with a very bad smell (think sulpher as a posed to fuel, but wife says it smells rich), rough running when cold and smooth[er] running when warm. I have been going over everythng I can trying to figure it out. I have replaced the coolant temp sensor (2 wire), air/fuel mixture sensor (was nasty black), IAC (also nasty, wouldn't clean), and O2 sensor. I pulled codes and got TPS low voltage and O2 always lean. I tested the TPS and seems to be in spec. I have it adjusted down to .8 at the moment and it is at 1200 rpm, at .91 it sits about 1800 rpm. At WOT it is just under 5. I don't hear a vacuum leak and have checked lines and connections. The only line I don't seem to have any vacuum is the lines to/from the canister next to the radiator. These lines can be disconnected with out any change to rpm's. All others do make a difference. I pulled the plugs on the TPS and IAC and there is a slight drop in rpm. I pretty well soaked the motor in carb/choke cleaner but had no variation in rpm. I got curious (read frustrated) and placed my hand over the throttle body and got very good suction, the engine rpm's dropped and the engine stumbled then I got a very loud whistle seeming to come from the right rear of the intakes (as looking from the front end). This is what I was looking to get, but is this a possable way to identify a vacuum leak? I figure the engine would stall unless it could get air from a leak.
Let me what ideas y'all might have. Thanks.

 

[BRUTUS_T_HOG]

if it didn't stumble from carb cleaner sprayed on the intake then its probably not an external leak.

you can pull the oil cap off and check for excessive vacuum in the valve cover which would indicate an internal vacuum leak.

your brake booster doesn't hiss constantly does it?

 

[MJ'sBlkBII]

No, the booster doesn't hiss. I'm curious if it is a lower intake leak that the carb cleaner didn't get to. I belive I have coolant making it out of the tailpipe. I fire it up from cold and after a couple of minutes it starts smoking and then water starts dripping. It will do this after it has warmed up and leaves a much larger-than-condensation puddle on the ground. I can shut it down and fire it up after only 30 minutes and it will repeat the issue. Driving it seems to stop the smoke and water, but I haven't let it idle long enough after to see if it resumes. The heads are "supposed" to be new. The previous owner said he had overheated it ad had them replaced. The coolant was just flushed because it was brown. I just looked at the overflow and the coolant again seems to be the same color. This is leading me to belive if it isn't lower intake either the heads or the block is cracked. Compresion test is getting done here as soon as it cools off. When I bought it the oil looked new, will be inspecting it again.
Excesive vacuum: I take off the air tube and can hear the IAC pulling air. If I plug the TB port to the IAC with a finger it was stall. I do not seem to have a lot of pull from the PCV port or the breather valve port of the TB.

 

[MJ'sBlkBII]

Got the compression test done. These numbers are are after letting the gauge sit while I prepped the next plug. Figured this would give a sort of leak down test. All dropped less than 5 psi. Gauge only has 5 psi increments.

1-165
2-165
3-155
4-145
5-145
6-160

This tells me the rings and head gaskets are good! Leads me again to the intake gaskets. I shot a bit of brake cleaner (grabbed the wrong can) at the back of the engine/lower intake, as best I could, and got a little pop so I belive I'm being pointed in the right direction. Checked the oil and it still looks new. I've got the gaskets so I will tackle that today. Here's to hoping!

 

[MJ'sBlkBII]

Welp... I changed the intake gaskets. Idle was where it should be. It had gumption. Rpms at speed was 1K lower. 65 seemed faster and it wasn't struggling! Then I don't know why, but it all went back to the way it was! !@#$% No power, RPM's running about 500-1000 high, and idle is back up to 1600. Pulled codes and again, I got KOEO-63 and KOER-13. The 13 confuses me since it's idling high. Disconnecting the TPS actualy increases idle though. Disconnecting the IAC makes no change. Makes no sense. Thinking the RTV in the valley may have moved.

 

[Spitfire1975]

I have been having the EXACT same issue. I think everything is leading to a warped intake manifold that holds good idle when the gasket and rtv is new, then heats up, twists, breaks the seal and the idle goes all to hell from that point on.

I know this is an old post, but maybe it will help someone else.

 

[holyford86]

Sounds like your IAC is bad and your TPS is adjusted too low

 

[Spitfire1975]

I don't know about the OP, but my IAC is now brand new.

When it heats up and then idle goes to hell again, after the gasket change, you can hear the leak back by the distributor when you block off the throttle body and choke out the engine.

 

[BRUTUS_T_HOG]

try to pinch off vacuum going to the PCV valve

 

[Spitfire1975]

Ok. PCV Valve also brand new. What am I/are we looking for?

 

[BRUTUS_T_HOG]

PVC rate of flow is critical. Aftermarket PVC valves do not match original flow rates and cause a large vacuum leak. If the engine runs better with the vacuum into the PVC blocked off then I would try to locate a new motorcraft PVC valve with the correct flow rate for your size of engine. I'm working on a 91 escort right now that runs lea at idle because of the NAPA PVC valve and ford says they are discontinued so I'm going to put a restrictor in the hose

 

[Spitfire1975]

PVC rate of flow is critical. Aftermarket PVC valves do not match original flow rates and cause a large vacuum leak. If the engine runs better with the vacuum into the PVC blocked off then I would try to locate a new motorcraft PVC valve with the correct flow rate for your size of engine. I'm working on a 91 escort right now that runs lea at idle because of the NAPA PVC valve and ford says they are discontinued so I'm going to put a restrictor in the hose

gotcha. Did not know that.

How does/would that affect hearing the leak by the distributor when blocking off the throttle body?

 

[BRUTUS_T_HOG]

gotcha. Did not know that.

How does/would that affect hearing the leak by the distributor when blocking off the throttle body?

well im pretty sure the PCV valve is back by the distributor so you could be hearing the flow through the hose, or what i would think could be leaking is the gasket that goes between the lower intake and the fuel rail. they usually rot out right at the back of the intake and always get ignored when the intake manifold is removed cause the fuel rail doesn't usually need to be removed from the intake, thats why you get two upper intake gaskets in a kit. I don't actually know the details of your truck though

 

[Spitfire1975]

... or what i would think could be leaking is the gasket that goes between the lower intake and the fuel rail. they usually rot out right at the back of the intake and always get ignored when the intake manifold is removed cause the fuel rail doesn't usually need to be removed from the intake, thats why you get two upper intake gaskets in a kit.

There's a gasket between the fuel rail and the lower intake????? Maybe this is where I am going wrong. I thought the only "seal" on the fuel rail was where the injectors and fpr were attached.

I have now replaced the lower intake manifold 3 times. Still leaking back there. I replaced all the gaskets that came in the set (lower and upper manifolds, throttle body and IAC. It also came with what looked like a carburetor gasket, but I did nothing with it, figuring it was an extra depending on the application.

 

[Spitfire1975]

The injector o-rings have been changed within the last 15,000 miles.