NEW PROBLEM(S):

[Stewart G Griffin]

Yes, i didn't think there was that big a difference---i installed the new seat.  The carb is back together.  i don't see what everyone fusses about? 

For the choke arm, i tilited the carb on its side and then guided the arm in with a paper clip and then was able to match it's angle with the choke lever rod's "dowel" setting.  For the power piston i stuck a thin screwdriver on it to keep it from popping up while i lowered the airhorn down and then slid the screwdriver out at the last minute.

The most time consuming part(besides getting the tools, reading and waiting for the parts to come in) was actually waiting for the carb cleaner to dry.  After it dried and the petroluem smell went away, i was able to take it all inside and assemble it, because it is getting cold around here.

So, hopefully this solves the problem.  If not, it's probably the pump.  i'm running out of things it could possibly be.

[eventhorizon66]

Even if it doesn't solve the problem, you now have a nice "like-new" carb.  And it was a valuable learning experience.  Are you using the 1/4" thick heat insulating base gasket?

[Stewart G Griffin]

It's pretty thick, i'll have to measure it.

[eventhorizon66]

No need.  I was just making sure you ended up with the right gasket.  It it's "pretty thick" it's the right one.

[Stewart G Griffin]

OK, so i think i've pinpointed the problem----there is serious flooding going on;  The new airhorn-to-main bowl gasket was drenched with gasoline, there were puddles of gas on the intake manifold and there was gas on the flare nut(i didn't tighten it enough).  Also, before the carb was rebuilt and this overall problem started happening i subconscienciously noticed these puddles but thought that they were coolant, possibly due to not having enough lighting, also the air cleaner was probably blocking my view.  Thus, i didn't consider it a problem.

The reason why i was able to tell now is i know what a new gasket should look like and could tell right off the bat that gas was getting on it whereas the old one was probably pretty drenched to the point where it changed colors.  i know that the fuel level in a quadrajet bowl should be at most 3/4 full and definitely not higher than the bowl top.

During the carb rebuild, i put in a new float and checked the level to be good.  i also vacuum tested the new needle+seat and put in a new filter.   i also checked the old needle+seat, float and those were found to be good and at the right levels.

So, assuming the carb itself is not the problem, what else could cause flooding?  Is it possible for a  pump to go bad to be putting out too much pressure?  The other possibility is there could be trash in the fuel system, but i don't think this is likely as when i rebuilt the carb, it wasn't that bad.

NOTEs:
a) i have a vapor return line on the pump.

b) the service manual says there should be 5-9 lbs. (will provide more detail later, don't have the service manual in front of me---i'm at work)  This sounds like too much?

i wasn't able to test the pump pressure last night, will probably be able to get to it tonight.

[Stewart G Griffin]

OK, scratch the previous post;  i took care of the flooding all over the intake manifold problem--what happened was the inlet nut was not tightened enough.  i saw it today because what happened was i got my fuel pressure gauge hooked up and in order to see it, i had to start the engine and then rush over to the front of the truck.  And i'm glad i did because it was gushing out.

So anyways, fuel pump pressure is ok--within limits.  And by the way to clarify--the service manual says 5.5-7lbs. for small blocks if you have a return line.  If you don't have a return line, then 7.5-9lbs. small and big block.   Big block with return line is 7.5-9lbs.  And all inline 6's 4.5-6lbs.

No improvement.  We are basically back to square one.  i will try to get a video up on how the vacuum gauge is acting.  i don't think, at this point, that the carb is flooding but i'm not ruling it out.  i guess the next thing to do is check the float with the engine running.  i know you need a special tool for that.

i'm looking towards a sticking valve, although i have my doubts about that;  Let's say that a sticking valve or lifter was causing the engine to run crappy at idle.  Wouldn't this also cause the engine to run crappy at higher rpm also?


2) i think at this point we should talk about the "pouring something in the carb while the engine is running thing."  i have heard about this and i actually once saw some mechanics doing this but up until a few minutes ago (i've been doing some more reading) i didn't know what they were doing.  Supposedly this help free up sticky valves.  It could not hurt to try this.  My engine was installed in 97.   i think it is called seafoam?

[Irish_Alley]

I've heard pour a lil bit of oil in the carb and watch for smoke to come out of the engine, shows if you have a vacuum leak. now seafoam goes in the crank case and fuel tank to clean the fuel system and you add it to the crank case to quit "noisy lifters" that ain't your problem tho.

[eventhorizon66]

Maybe you could use a product like Seafoam as preventative maintainence, but not as a fix-it.  And I realize that people do it, but adding it to the crankcase just seems like you're asking for a spun bearing.

[Stewart G Griffin]

OK, i think i'm going to hold off on the seafoam/marvel mystery oil etc. for now;

At this point i wish to profusely thank everyone for all the help.  It seems like interest in this problem is waning and i totally understand----it has dragged on WAY too long---over a month.  If anyone wants to drop out, this is totally understandable.  i will still soldier on, although it might be at a slower pace.

i think what i'm going to do now is to anally go back thru everything and do it right starting from the ignition system. i'll just read books and i won't come to the net and post every little detail unless i really get stumped.

Well, actually, before that, i'm going to try one last thing for this community effort and that is to post a video of how the truck is running and what the vacuum gauge is doing.  i think that will really help.

[eventhorizon66]

I think that your ignition system would be an excellent place to start (or continue, rather).  You know your carb is newly refurbished so that eliminates it as a suspect, unless it just started a new "misbehavior" after the rebuild.

Also here's a guide for reading a vacuum gauge.  Tuning with a vacuum gauge  Here's one with an animated gauge.  How to Use and Interpret a Vacuum Gauge  Not sure about the accuracy, but check it out.  Posting a video may help the pro's (not me, LOL) here help you, so that's a great idea.  Good luck.

[Irish_Alley]

stewart you vac gauge will read funny cause your engine is loaping you can't get a accurate read in it till you fix the loaping. every time you hit the low rpms you gauge will drop then when it hits the high rpm it will increase

[Stewart G Griffin]

test video

[Stewart G Griffin]

i'll get the video up a.s.a.p.;  It's too dark and i'm trying to find a way to brighten it.

In the meantime, if after you shut an engine off and see vapory stuff coming out of the carb is this normal?  This is sort of like a dry ice type thing you might have seen at rock concerts (they don't do it anymore because everyone stinks these days, but kiss, rush etc did it).  It's not true smoke but it looks like it.  If i open the throttle by hand it really comes out.

[TexasRed]

That's gasoline. Sounds like maybe you still have carb problems? Is your well plug leaking?

[Stewart G Griffin]

OK, i finally got my video right.  It's not great, but it's the best i can do for now:

First off, i apologize for the poor quality;  i can't quite figure out how to get regular, non-digital videos on the net, so i used my digital picture camera's video mode, because my digital camera has a USB plug in to the computer and my video camera doesn't---and then my battery ran out and i'll explain the significance to that in a sec.  Also, the video was too dark, so i downloaded a free video editor called EnhanceMovie, thus the logo flashing in and out.  So i apologize for that as well;  i'm not trying to give them an advertising space, although i thank them for brightening up my video.



So what is happening is that when first started and on high idle at 1200rpm, the vac gauge is steady enough to be "normal."  If it drops below that then the vac gauge starts acting haywire.  Now, what happened was my batteries on the camera had run out.  So what eventually happens is as the choke opens all the way and it comes off highstep, it will go down to 800, 700, 600, getting very more unsmooth as the rpms go down and then it will stall out.  While it goes to 700, 600 rpm the needle goes even more wild with the swinging  from the 9o'clock position to about the 3o'clock position.   i think the video actually sounds better than the actual situation---it's much rougher sounding--like a funnycar at the starting line.  Also when the engine revs up, it's not doing it on it's own.  That's me bringing the rpm's up and/or keeping the engine from stalling out.  i think the soonest i will be able to make another video is tomorrow or wed.


i will solve this problem.  The question is when.