[paul8755]

Hi everyone, I need some help, I am really confused!
I have a 1978 Pace Car.
My problem is that if I wait a few days to start the car it has a tuff time starting and this is what I have done!
I usually had to pour starting fluid to start, so I decided to take the car to a mechanic and they decided to rebuild my Rochester 4 barrel carburator, after they rebuilt my carb and got home the car is still showing signs of the same problem, called the mechanic and he says it now may be the fuel pump.
What do you guys think?
Is it perhaps a fuse or relay or what other than the pump?
I have already order the pump but I want to make sure.
Help. please.

 

[C3blackvette]

A common problem with Q-Jets is fuel leaking down from the bowl overnight and having to crank to get fuel back in at start-up time. This should have been addressed when the carb was taken apart by a profession carb rebuilder.

If the carb is not set up properly for a cold start, it will crank excessively. (Choke Pull-off)

If the engine runs fine on the highway,especially in passing mode, it's probably not the pump. I believe there would be a drive-ability problem with a weak or bad pump (stalling, bucking, hesitation).

If you suspect the fuel pump, disconnect power to the ignition, disconnect the fuel line from the carb and securely attach a short hose into a can. Crank the engine for a few seconds and check the amount in the can. There are spec's for the time and volume, but have somebody crank the engine while you watch for the flow. Don't do this in the garage and have a fire extinguisher on hand just for safety! This is not a difficult task, but it involves gas/gas fumes, get some help if it's the first time.

Based on just what you wrote, I would recheck the carb adjustment first.
No professional mechanic that I know replaces a fuel pump without checking it first.

Hope this helps :cheers:

PS - Before you do anything, if the car sat overnight or longer and fuel really is leaking down from the bowl, when you work the accelerator you may get a couple of good squirts of fuel down the carb from the accelerator pump and then very little.
This is all based on a good ignition system and spark at the plugs.

 

[[email protected]]

I m betting on heat-soak.. in hot weather, you shut the engine off in hot weather,heat transfers to manifold, then carb as it rises... it literally boils the fuel out of the carb .. you have an empty carb and a manifold full of fuel the next morning..thus,hard starting .. a phenolic spacer will cure it

 

[paul8755]

Thanks a lot for your input.
The carburator expert did tell me about the quad jets leaking inside thru the screws in the bottom of the carburator.
he was very careful in sealing those screws with some kind of epoxy to make sure it doesnt leak, he says he has been rebuilding carburators professionaly for 20 + years.
I called him a couple of days after i brought the car home and told him that it wouldnt start!
He said that when he finished rebuilding the carburator he had a hard time starting it and it should have not been that hard he was thinking that the fuel pump may have been laboring a bit!
Now, let me add, I live in las vegas and right now it is very hot, 117 degrees, the other person that responded may be correct, perhaps i need a spacer.
What do you think?
When the car starts i have no problem at all.
The car also stinks a lot like fumes after i drive it and i also think i have to replace the vapor canister.

 

[paul8755]

Thanks a lot for your input.
I think you may be correct on the heat las vegas is 117 degrees now, the only question i got for you is, why didnt the carburator guy said anything about this?
Thanks.

 

[[email protected]]

you should ask him...its a common problem in hot climates.. you live in Vegas, its hot......likely cause

 

[paul8755]

I did,
he said that he does not like to use phenolic spacers because then you have to adjust the linkages and so on.
He really thinks there may be something wrong with the pump, perhaps not been 100%.
Anyways I have ordered the pump and I have my mechanic install it for me and once and for all find out what it is.
Thanks

 

[[email protected]]

good luck, hope that cures it........but if not, this is what a phenolic insulator looks like.they .come in 1/4 inch all the way to 1 inch thickness..it will cure heat soak http://www.ebay.com/itm/Rochester-P...eat-Soak-Riser-Quadrajet-1-4-OP-/231000512089

 

[C3blackvette]

paul8755,

Just curious, while the mechanic had the carb apart, did he actually check to see if the well plugs were leaking?
I have never tested one and actually seen one that was leaking, I really think it's over rated. To fix it professionally, the plugs need to be drilled out and tapped for an machine screw with a good epoxy. Simply spreading epoxy on the well plug is not a permanent fix.
Another rare issue would be that the bowl is porous and that's not something that gets checked during a quick rebuild.
These are issues that need to be revisited if the fuel pump doesn't change anything.
Before replacing a fuel pump that hasn't been checked for pressure or volume output and doesn't show any signs of a weak pump on the road, I would go with the spacer recommended by fishslayer. You just need longer studs/bolts and it could be a cheap, quick fix.
Good luck and stay cool in that 117!

 

[paul8755]

Thanks.
I will probably order the phenolic spacer,
will keep you guys posted.

 

[toobroketoretire]

Thanks.
I will probably order the phenolic spacer,
will keep you guys posted.

Before ordering anything check the fuel pump's output. It should pump out 1-1/2 pints in 30 seconds of cranking. And the smell of gasoline could be coming from either a leaking fuel input line or fuel return line as the hoses don't last forever nor do the steel lines.

 

[paul8755]

OK guys.
I receivd the phenolic spacer and 2 cardboard gaskets. I isntalled this morning and after I was done the car did not want to star, it backfires a bit.
Do you think that I have to mess with the timing at all?
I tightened everything pretty well I dont think there is any air getting in the base of the carburator.
I need help guys.
Thanks.

 

[[email protected]]

you put a gasket above and below the spacer?...bolts are tight? ..spacer has nothing at all to do with timing.. unless you unintentionally moved the distributor while you were installing.. did you turn carb on its side? it may be out of fuel, spin the engine without touching pedal, to pump fuel into it .. check all your vacuum hose connections and plug wire firing order if you removed any from cap

 

[paul8755]

Yes, i put a cardboard gasket below, phenolic spacer in the middle and cardboard gasket on top like a sandwitch.
I tightened the bolts, I had to buy bigger bolts because the original were not big enough, I did not touch thge distributor at all, I did turned the carburator a little bit and disconected only the fuel hose coming into the carburator in order to move it so I can have space to install the hardware.
I did spray starting fluid inside the carburator in order to start the engine, because it would not start without it!
After I started the engine and consumed all the fluid I sprayed, the car stalled and would not want to start again.
I pumped a few times and sometimes it backfired but the car would not start on its own.
The only things that I may not be sure 100% is the vacum hoses are in the correct place.
Thanks

 

[[email protected]]

look in the front bores of the carb and open the throttle. quickly....do you see a strong stream of fuel squirting in ? did you replace the fuel pump like you said you were going to? and install a new filter? sounds like no fuel getting to carb. the spacer would have no effect like that unless its the wrong one and its not fitting/sealing on the manifold

 

[paul8755]

I will do that.
I did not replace the fuel pump yet, I was waiting to see the results of the phenolic spacer yet.
Perhaps you are correct about having the wrong phenolic spacer, because before all this all I had was no fuel in the carburator and I rebuilt it, maybe the pump still needs to be rebuilt but I never had the carburator back fireing before until I installed the phenolic without gasket and no with gaskets.

 

[paul8755]

I have a friend of mine come over my house to check the car, he is a professional mechanic and he owened his own shop for 25 years, He asked me not to touch the car anymore until he checks it out tomorrow.
Hopefuly he can find the problem tomorrow and no matter what I will post the results, worst case I will just take off everything and leave it the way it was and perhaps replace the pump.
Thanks.

 

[paul8755]

Ok guys.
I have actually installed the phenolic spacer the wrong way!
I was lazy and I did not want to take off the carburator completely off the car so I loosen some stuff just in order for me to slip the spacer in. oops!!!
I guess there were two ways of installing it.
The wrong way and the right way!
Now the car does not backfires at all and it has a lot more power.
I guess now I have to wait until the next day to wait for it to cool off and see if the car starts ok in the morning, which it was my original problem, if not the I will just replace the fuel pump and I should be ok.
What do you think?
Thanks for your feedback.

 

[C3blackvette]

Good to hear it was something simple. Hopefully it's fixed. :thumbsup3:

 

[[email protected]]

DUUUUUUUUDDE? you got to pay attention..slow down.. if you don t have time to do it RIGHT, do you have time to do it TWICE??? you are not the first to make a mistake, don t worry about it.. I m glad you solved the mystery.....now, it should solve your heat soak problem and boost a little HP too