Jeez it's always something....

[beanhead]

Not sure what happened....rebuilt my demon carb last weekend because it had a little leak, plus it sat in the garage for 10 years before I used it. Had a feeling my intake seal wasn't perfect either so I re-did that while I was there(found oil getting into the ports)- 440 with edelbrock heads&intake, comp 274xe cam, compression 9.5-10...motor used to pull a wavering 14" vacuum at idle and required some feathering on cold starts. Since the carb/valley pan re-do, this thing has been awesome...fires right up, crisper throttle...even sounds stronger, and getting a fairly steady 16-17 at idle...until today. Pulling in the garage it began to stumble and could barely idle, vacuum down to under 10, hardly runs now...float levels good but changing carb settings didn't help..what the frick.Timing set at 20-ish idle, hits all in at 38... Don't have time to monkey with it until the weekend so I'll check the plugs, ignition stuff, do the spray-for-leaks test but what a bummer...ok, mostly just venting here..any thoughts?

 

[not so famous bob]

Not sure what happened....rebuilt my demon carb last weekend because it had a little leak, plus it sat in the garage for 10 years before I used it. Had a feeling my intake seal wasn't perfect either so I re-did that while I was there(found oil getting into the ports)- 440 with edelbrock heads&intake, comp 274xe cam, compression 9.5-10...motor used to pull a wavering 14" vacuum at idle and required some feathering on cold starts. Since the carb/valley pan re-do, this thing has been awesome...fires right up, crisper throttle...even sounds stronger, and getting a fairly steady 16-17 at idle...until today. Pulling in the garage it began to stumble and could barely idle, vacuum down to under 10, hardly runs now...float levels good but changing carb settings didn't help..what the frick.Timing set at 20-ish idle, hits all in at 38... Don't have time to monkey with it until the weekend so I'll check the plugs, ignition stuff, do the spray-for-leaks test but what a bummer...ok, mostly just venting here..any thoughts?

what gas are you running? a lot of timing for panther piss !

 

[beanhead]

Pump 91, worked fine until yesterday...

 

[dieseldazzle]

Needle and seat probably got some junk in them

 

[PurpleBeeper]

Carb cleaner is cheap & takes 5 min. My second guess would be to look at your ignition..... wires backed off? fouled plug(s)?

 

[beanhead]

Thanks guys, yep have to start with the basics..just hoping it's something external at this point

 

[beanhead]

Well here's what I found out so far... carb cleaner test showed no leaks, when I unplug any of the plugged vacuum ports on the carb idle and vacuum increase. Same with the PCV, if I just pop it out of the valve cover leave it connected to the carb things get a little better... Starting to look like a carb/fuel problem it's just weird the way the carb was set it worked great up until yesterday.... still not getting my vacuum where it was without setting the idle too high, at a good idle speed I'm getting 14-ish. It was doing between 16 and 17

 

[beanhead]

By the way all the ignition components checked out okay

 

[miller]

Just a couple things. Fuel filter...might want to look at it. And, rubber fuel hoses. Some types get eaten up, by the gas. I was told to use Gates fuel injection hose, that will hold up good. Don't have the part number. Looked at a different brand...made in china, US brand...laughed, and walked away!

 

[beanhead]

Thanks, I'm starting to think the valley pan may be leaking inside again. Had that problem before, due to permatex non-hardening type sealer(used pan only). Regardless of what temp it's rated for, when it got warm it oozed and created gaps between the valley and intake ports, and between the ports themselves. So this time I used the paper gaskets (aluminum heads&intake) and stuck them to the pan with hi-tack, then used copper spray between the paper and aluminum surfaces. Worked great for a few hours and guess what. The hi-tack never fully dries either and after being heated for awhile is oozing out from under the intake, I can probably assume it's doing the same inside where I can't see. I have used edelbrock's gaska-cinch but it's a pain to get apart, seals well though...

 

[eldubb440]

Same with the PCV, if I just pop it out of the valve cover leave it connected to the carb things get a little better...

probably not the main culpret, but do you have a vent on the other valve cover, or is it clogged?......... you should notice no difference when popping the pcv out of the valve cover........ the pcv valve is a metered vacuum leak and yours is starving for air

 

[beanhead]

probably not the main culpret, but do you have a vent on the other valve cover, or is it clogged?......... you should notice no difference when popping the pcv out of the valve cover........ the pcv valve is a metered vacuum leak and yours is starving for air

The breather on the other side is clear, my other thought is it's the carb...even though I just rebuilt it and it worked great, I am going to blow out the passages again to be sure something didn't get stuck in there

 

[beanhead]

Welp! Pulled off the intake and, prognosis....oil. On the intake side of the pan, and the head side as well. Oil seeping into some of the ports, along with a little of the hi tack sealant that was pulling in there. That's strike two on this engine....as stated earlier, pan alone with sealer leaked, and now the pan+paper gaskets has leaked also..didn't really have a problem bolting it up with the papers in there but I'm starting to wonder if I have a fitment issue...I bought this motor back in 2001 as a rebuilt short block so I have no idea how much, if any it's been decked. Probably safe to assume it has somewhat, but is there a way to check/measure without tearing the heads off or worse? I know a good machine shop around here and can have them take a little off the intake if needed but would be nice to have a number for them...thanks everyone! Oh and what's a good way to seal this thing without using any of the permanently tacky or non hardening sealers? Will a fuel safe RTV type work? I know, right?

 

[beanhead]

.....and it keeps gettin' better!! Looked down the intake ports with a flashlight, and in the ones that had the valves closed there was a nice little puddle of oil in there, maybe half a teaspoon I rigged up some tubing to the end of my small shopvac and got it out then did the best I could poking paper towels down in there to wipe the rest out....explains why this thing has had the issues it's had, I'd say! It's not a 2-stroke! I am surprised it's run as well as it has with all that oil going through the chambers and I've never seen a hint of blue smoke...a good intake seal and we'll be golden!

 

[oldbee]

Have no idea how to check with assembled motor, but you definitely have a fitment issue.

 

[beanhead]

After some checking, that's the problem..so tomorrow off to the machine shop I go. Big hassle but glad I at least know what to fix now

 

[Lionized]

You should be able to see a slight step where the head meets the block if either the heads have been milled or the block decked (or both). Take a look at the front of the engine right where they meet. If the head is set back slightly, there's going to be problems with the valley pan sealing.

 

[beanhead]

You should be able to see a slight step where the head meets the block if either the heads have been milled or the block decked (or both). Take a look at the front of the engine right where they meet. If the head is set back slightly, there's going to be problems with the valley pan sealing.

Thanks that's good info! Uncut edelbrock heads on here, just went out and took a look and howdy-freakin-doody there's a little step..

 

[Lionized]

Thanks that's good info! Uncut edelbrock heads on here, just went out and took a look and howdy-freakin-doody there's a little step..

This is a kinda long video but it describes how to modify your valley pan in this situation. This is actually how I found out about this particular situation.

 

[beanhead]

Thanks Lionized, I considered that but decided to just get the Hughes two piece set up to avoid pulling a head...( I finally got my valve covers to stop weeping lol!)