'84 K10 Sub: Gas dripping from Exhaust

[93w/t1500]

My poor '84 Suburban (350, Q-jet, SM465, non CCC) has been experiencing some horrible drivability problems. In fact I had to tow her back to the house yesterday. Starting a few months ago I had a problem where she would hesitiate going uphill and then stabilize once the load came off the engine. That progressed to stalling fits when the engine was under load and finally stalling whenever I gave her more than 1/4 throttle. As far as I could tell the engine was flooding out so I pulled the Quadrajet and rebuilt it this weekend. I put it back on the truck and she started fine so I went for a test drive.
She ran fine for about 5 minutes and then started stalling again. The difference was that it wouldn't clear up once restarted. If I held the throttle nearly floored I could keep her running roughly at about 1100 RPM or so but she would die whenever I tried to let the clutch out. The truck was definately running rich again...in fact the cat was glowing cherry red and the undercoating was starting to cook off the underbody.
I got her home, pulled the Quadrajet and checked it over again. Everything seems to be ok but I didn't get metering rods and jets in the rebuild kit. I started her in the driveway and had the same symptoms except a puddle of gas formed and it was dripping from the joint between the manifold and the header pipe. The intake had puddles of gas in it as well.
I'm assuming something is completely shot in the carb...either the metering jets or the power valve but I'm not 100% sure it's a carb problem. Could this be a symptom of a plugged exhaust system?

[84 400]

carb sounds bad. sounds like power valve is done for. Also it sounds like you have a clogged Cat there!!! i would replae the cat and carb and be done with the problem

[93w/t1500]

Thanks. That definately makes sense. The power valve controls the depth of the metering jets and it didn't look to be in the greatest of shape. I'm going to order the replacement carb tomorrow but I wondered if I could check the cats before replacing them (dual exhaust=2 cats). If they were plugged would the truck idle ok? Then I could hook a vacuum gauge up and check for a restriction.

[93w/t1500]

I replaced the power valve, metering jets, & rods last night and, after a little coughing, I got her to start again. From what I could tell the power valve wasn't moving freely. Of course I haven't driven her yet and I still need to figure out if the cats are shot but it's a start.
Here's the question. I ran her until she warmed up and then changed the oil (I figured it was watered down with gas). It was MUCH worse than I thought: I drained 1.75 gallons of oil/fuel out of a 350 with a 5 qt capacity (-1 qt for the filter). I thought it would never stop...I had to change drain pans. Anyway I started her up with fresh Castrol and she clunked for about 3 seconds and then cleared up. What would oil that diluted do to my engine? It ran for maybe 15 minutes total before I changed it out. I suppose if nothing else it probably dissolved a lot of sludge. I had 25-30 psi on my mechanical gauge after I changed the oil, which seems ok but the factory manual doesn't list an oil pressure spec.

[84 400]

well my 85 305 used to idele at 30 psi and my 84 with the sb 400 idles at 60psi. but that is not important for you 30 sounds about right to me. The reason i say the cats are bad is because you stated they were glowing red! that would indicate that they are clogged. try driving it for a few days and run the gas out of the pipes and then look under. if it is still glowing red then they are clogged and need rplacement or just run a straight pipe in there place. i don't know what your laws are though. Hope the power vavle does it and it sounds like the colprit to me. Also when i had gas in the oil it was from a leaking fuel pump diaphrame wonder how your fuel pump is ?

[aggiedave98]

Originally Posted by 84 400

well my 85 305 used to idele at 30 psi and my 84 with the sb 400 idles at 60psi. but that is not important for you 30 sounds about right to me. The reason i say the cats are bad is because you stated they were glowing red! that would indicate that they are clogged. try driving it for a few days and run the gas out of the pipes and then look under. if it is still glowing red then they are clogged and need rplacement or just run a straight pipe in there place. i don't know what your laws are though. Hope the power vavle does it and it sounds like the colprit to me. Also when i had gas in the oil it was from a leaking fuel pump diaphrame wonder how your fuel pump is ?

probably a dumb question, but if you don't have a mechanical fuel pump, is there anyway for gas to get into oil???

[84 400]

Originally Posted by aggiedave98

probably a dumb question, but if you don't have a mechanical fuel pump, is there anyway for gas to get into oil???

oh did he have a elctric one on his 84 350? Thats my fault sorry i just though being an 84 pre fule injection truck it had a mechanical one. i guess i need to read his post more colsely but i don't recall seeing a elcetric pump in them. I don't mean to sound sarcastic so if i do i am sorry it is an honest mistake. and if it does not have an elctric fuel pump i have heard of gas seeping past the rings when really flooded

[aggiedave98]

Originally Posted by 84 400

oh did he have a elctric one on his 84 350? Thats my fault sorry i just though being an 84 pre fule injection truck it had a mechanical one. i guess i need to read his post more colsely but i don't recall seeing a elcetric pump in them. I don't mean to sound sarcastic so if i do i am sorry it is an honest mistake. and if it does not have an elctric fuel pump i have heard of gas seeping past the rings when really flooded

I would assume he has mechanical as well, but was wondering if it was electrical, how would gas get in there... i didn't think about seeping past the rings, but would think that's only a little amount and only when it's not running of course... not enough to see in your oil.

[84 400]

sorry abot sounding sarcastic i just was under the impression that you thought he had in elctrical pump my bad. The seeping in the rings is the only thing i have ever heard of and the mechanical fule pump i have had personal experiance with.

[93w/t1500]

It is a mechanical fuel pump (no computer controls at all, all mechanical federal emissions) but it's only a year old. I'm pretty sure all the gas came past the rings when she flooded out. But I do have good news: she seems to be running fine. I did the vacuum test last night and it said my cats are ok (20" vacuum at 1,000 RPM and at 2,000 RPM). I changed the plugs and set the fast and slow idle, then took her for about a 15 mile drive. The oil pressure was 25-30PSI, everything sounded good, and it only stumbled once. I think the stumbling is due to the fact that my tank is nearly empty and I was climbing a fairly steep hill. So far, so good

[84 400]

glad to hear it man !!!!!!!!!!!!!
hope fully she stays that way for a lonnnnnnng time