Head gasket?
 

He all, thanks in advance for your help..
Long story, but for numerous reasons my Firebird (455, 6x 8 heads, Crower 60210 cam) has been garage bound for a the better part of the last 4 years, it’s been started and warmed up but not run much.. and I say in the past 2 years it’s hardly been at all.

I made all the mistakes as far as letting the gas sit, not draining anything etc.. but ironically it fired right up last week before the carb gave up. I cleaned and rebuilt the carb (Holley 750 vac sec) changed the oil and filter, new plugs all around and finally got it going again.. it was not smooth and the smoke coming out was pretty bad.. first very black the it eventually cleared up.. in the process of trying to start it I have become hopelessly flooded prior to the carb rebuild and oil change.

The next item to fail was the fuel pump.. carbs would run on id but due on throttle.. I was able to verify no fuel coming from the pump. I’ve had the diaphragm go before.. but I also noticed a wet spot on the headers by 3 and 5 where it bolts up to the head.. it is likely that the head gasket has also gone?

I’ve orders new head gaskets, header gaskets, intake gaskets, and fuel pump. Should I pull the head before trying to start it with the new pump? Is there any other way to verify if the gaskets blow ? The oil thst I took out was not milky at all; so I’m thinking if it did go it was yesterday.

Thanks.. and yes I know that the majority of these problems are self inflicted 🤦*♂️

I would see if you could rent from a tool rental place or borrow from someone a radiator pressure tester before yanking the heads off.
I can’t see why what was a good head gasket would let go unless a whole lot of fuel got into the motor and hydrolocked it !

Thanks.. I’ll see if I can track one down.. would a compression test or give me a good indication as well? They have some cheap ones at harbor freight

No, it’s very possible to have a coolant leak yet have perfect compression in all 8 cylinders.

you said you changed the oil/filter, did you drain the old fuel out of the tank? i would assume so but if not get some fresh gas in there ASAP.

based on the oil & coolant not being milky i would go ahead & start it again after the new pump, the cranking & starting you did should not have blown a head gasket... but doing more testing is a good idea. if it was flooded, pull & clean the plugs then dry them out before reinstalling.

X10 clean out the tank, lines, and carb and recheck. Compression test found a blown head gasket on my car(between cylinders) last year.

1`st I would grab a torque wrench and check all head bolts.

Thanks for the input! I’m borrowing a coolant system tester this weekend. I didn’t drain the gas.. there want not much in it and it eventually ran dry.. I put 4 new gallons in… it ran on this prior to the fuel pump giving up the ghost. The fuel filter is also clear.. I ran water through it to to see if it was clogged from tank gunk/sludge before I settled on the fuel pump being bad…. But as I write this I realize the filter is after the pump so I’ll check the lines…

Just wanted to follow up and say thanks.. the only head gasket that was blown was on top of my neck.. i did a compression test and it was fine (between 160-180 on all 8) changed the fuel lines, put in the new pump, after the pump was primed it fired up pretty quickly. Let it run for a bit, no leaking where I thought I had seen it before. I also had to change my oil pressure gauge hose and the oil (what little there was) was perfect. Still running way to rich but running. When I rebuilt the carb (holley vac sec 4150) it had 72 jets.. should I bring it down a littl to try to get it not so rich? Hope to road test it this weekend and also thinking some actual driving will cure a lot of the running at idle idiosyncrasies. Thanks

MAIN JETS DO NOTHING AT IDLE.

Food for thought. Having the Primary Throttle Blades in the wrong spot on the Transfer Slots will not help either. What is, your idle rpm?

Tom V.

X2 with the above!
At idle are you seeing fuel dribble out of the primary side boosters?
It good you changed your oil, how did it smell, like it had some fuel in it?

There are a few things that can make it rich at idle rich like mentioned about throttle position at idle causing transfer slots exposed. Other things it could be is float level set too high or the leaking fuel past the needle and seat due to either a dirty or bad needle and seat or too much fuel pressure.

The idle screws are 1 and 1/2 turn out. The floats were sitting half way up when I had the car apart, and the fuel sits at just about the top of the porthole on the carb. The primary closes as it should the best I can tell. . Right now it just does not want to idle at all.. has to be at like 1500 to stay running. I’ve tried moving the distributor, but haven’t had much luck. I just pulled the drivers side valve cover and there were puddles of fuel resting in it. Also I did see the leak on the header by 3 and 5, so now Im thinking it. Oils be a head gasket…it is smoking pretty good but now white smoke that’s why im not sure hers a pic of what a few minutes of running will cause.. and a pic of the gas puddle under the valve cover

Also.. before I let it sit for the past few years, it would idle at about 800-9..and start with 1 pump and one crank..

smokey could be from valve seal riding high on the valve stems

I rented a coolant system pressure tester.. seems to be holding but of course the set I have doesn’t have the right cap adapter, so it is leaking a bit from where generic rubber fitting goes in.. while trying it again somewhere between 15 and 20 psi it shot out the thing as well as some coolant. The coolant looks brand new if that’s an indicator. .. so I guess since there’s a good chance it’s not the head gasket, could the leak that I’m seeing just be condensation running out of the exhaust port and it be a bad header gasket.. the headers are basically impossible to tighten so that also seems like a possibility. Would you think it’s safe to run and work on the carb flooding issues? Thanks

Had it running for a short bit again.. same super rich gray smoke condition. I realized I hadn’t removed and cleaned the float screw and the needle and seat, took them out and we’re feet gummed up, replaced them with new once’s that came in my rebuild kit. Unfortunately concurrent to this I put on another carb that I have (850DP that I had taken off because I couldn’t get it to run right) it has been in a drawer for a few years but was empty of fuel when stored. Once on it started right up.. but then flooded really bad again. All the plugs were wet, and when I pulled #8 gas came pouring out of the cylinder. That was enough for me today… but I think I’m chasing a few problems
1. Carb needs to be adjusted correctly and functional
2. Though I have spark, I’m thinking it may be intermittent and lead to the lack of combustion and add to the flooding condition

The distributor is a petronix hei, it’s on its 3rd coil and 2nd ignition module. This makes me think it’s time for a new one, and the trouble I’ve had with this one could be from bad grounding.. so I’m going to replace all the ground on the car.. then start again with the carb.. and since I had gas come out of the park plug hole I I’m guessing I should also change the oil again as well…

Check the engine oil for gas contamination. I also recommend trashing the Pertronix and installing a stock points distributor for reliability.

You had better change that oil and filter just due to the possibility now of having a crankcase explosion no less poor lubrication next time you go to start it!

I definitely will.. just wish VR1 was a little cheaper.! But it’s cheaper than a new engine so there is that..