Community Forums

HoneyBadger · 05-17-2015, 05:33 PM

Quote:

Originally Posted by Speedjester

Sounds like a stuck needle and float... The needle and float is located on the front in the fuel bowl... With it off try tapping the bowl with the back of a screw driver...the older carbs do not like ethanol fuel..

Thanks for the suggestion- I've tried the tapping and its not unsticking what ever is es-stuck.

KSagal · 05-17-2015, 05:43 PM

If I had to guess, I too would guess the needle valve as well. If you are sure the gas is getting to the carb, but not inside.

I have had chevy engines with carbs that had a stone fuel filter right as the gas lines goes into the carb body, and have had that stone get clogged pretty quickly, so I might try that...

I recently had an 84 chevy MH that haunted me with carb issues, and a mechanic friend suggested a Eidlebrock, as they work right out of the box. The advice was sound, and it ran great, was a great investment.

I sold that MH 2 years later, not having had to do any more with the carb, and sold it with the spare rochester in the parts bin. (I think the new owner said he might rebuild it to have as a spare.)

Unfortunately for you, mine at the time was a chevy 350. (which had more carb options.) If you went to Eidlebrock, I would think you need at least a 750, but a 600 may work.

All this may be moot, as you already invested in a carb. If you have to pull it, will you want to put another rebuild from the same house?

Good luck. Keep us posted.

I am watching closely, as I am re building an 88 Southwind right now, with a 454 and I believe Rochester. I have not yet gotten to the engine adjustments.

talbott357 · 05-17-2015, 07:28 PM

I have had several quadrajets over the years on different vehicles. When they work, they are great, when they don't, they don't. It really does sound like a stuck float. Sometimes a few taps with a heavy screwdriver handle or the wooden end of a hammer will free them. I would definitely contact the tech line on the carb company, they will walk you through the trouble shooting on it.
I work in auto parts and handle commercial/garage accounts and deal with tech lines quite often. The people they have on hand are very knowledgeable and helpful. Parts stores can still get quads, but they run between 400 to 500 bucks.
You can also get a can of seafoam fuel treatment and try pouring a little down the throat of the carb and see if it knocks any dirt or debris loose.

JaycoEagle10 · 05-17-2015, 10:32 PM

HoneyBadger, YES the accelerator pump(if working properly) WILL squirt gas into the throats of the carb, even if float,needle is stuck. As long as, there's fuel in the float bowl. After all gas is run out of bowl, it will NO LONGER squirt any gas.

I've dealt with Rochester'ss. They're great carbs when working properly. Not the easest carb to rebuild however. They tend to warp often between the top/bottom halves and the between the air intakes, and many people don't run a flat edge along them to square up and just clean and throw on new gaskets hoping/thinking that's all there is to rebuilding carbs. Sometimes it does work, but more often than not it won't with Rochester's. If I remember correctly, they used a 750 quadrajet on a 454.

Call the company you purchased this carb from and see if they'll remedy your problem.

I've owned many older GM products over the years and if they used that carb filter that fits between the fuel line and carb(stone filter), just remove it and put an inline filter somewhere. Those stone filters are nothing but problems many times. Now, for a concours restoration, it would be different.

Another member mentioned a Edelbrock carb. DO IT. Even if you need to get a carb manifold adapter to switch from spread bore to square bore. AND. You have underhood room and fits your air filter housing, or you get a new performance "open" air cleaner system.

Just make sure the carb is around 700-780cfm to work with your engine, if you go this route.

terry735001 · 05-17-2015, 10:58 PM

i had 14 trucks i had to keep running

sounds funny but i found it better with the filter in the carb to take it out and drill a hole in the in of it and reinstall it to keep the one way valve so fuel would not flow back down the line and then right next to the motor i would install a see in fuel filter in the just befor the fuel pump

with todays fuel the paper filters go bad in 5 to 6 months
you see more smaller airplanes crash/stalled motor over using car fuel

HoneyBadger · 05-18-2015, 03:51 PM

Hey, thanks to everybody for your suggestions.
I took the carb off this morning to send back to the seller- but when I did, I realized that one of the vacuum ports on the carb was totally clogged with some black, gritty stuffy and the metal where the vacuum line attached was discolored.

????

Carefully cleaned the gunk out of the port and thought "oh, what the heck? why not?" slapped it back on and varOOM. She started right up.

Was it because the removing and reattaching dislodged the stuck float/needle? Or because of whatever that vacuum port was supposed to be doing?

If anyone has any idea what that crud was, I'd appreciate knowing. The vacuum line went ultimately to the intake manifold.

Happy as I was with the engine starting, I flung the old girl into reverse and promptly got stuck since the recent torrential rains in South Texas caused the left side of my "driveway" to turn into mush. 3 hours later AAA politely pulled the motor home from where I was mired, back up onto solid ground.

And now the brakes are sticking. *sigh*

KSagal · 05-18-2015, 05:47 PM

Vacuum is important to the flow of fuel inside the carburetor. Block it off, and you will not run. Restrict it and you will not run well.

The nature of a vacuum line being blocked, since it is a tiny vacuum cleaner, is that that black stuff may have been sucked from somewhere else.

First thing I would do, before I even started it again, and surely before I go mudding with it again (I couldn't resist) would be to get a fuel filter to go inline on the way into the carb. I used (on the last motor home, I have not yet done the engine work on this one) a glass filter housing with white paper inserts.

I was amazed at how much crap came up from the old tanks on my '84. I suspect my '88 current machine will be the same. I had all kinds of black bits and debris that got to that glass filter, and not beyond.

I will install the same type on my new one before the test drive.

HoneyBadger · 05-18-2015, 06:51 PM

Quote:

Originally Posted by KSagal

Vacuum is important to the flow of fuel inside the carburetor. Block it off, and you will not run. Restrict it and you will not run well.

The nature of a vacuum line being blocked, since it is a tiny vacuum cleaner, is that that black stuff may have been sucked from somewhere else.

First thing I would do, before I even started it again, and surely before I go mudding with it again (I couldn't resist) would be to get a fuel filter to go inline on the way into the carb. I used (on the last motor home, I have not yet done the engine work on this one) a glass filter housing with white paper inserts.

I was amazed at how much crap came up from the old tanks on my '84. I suspect my '88 current machine will be the same. I had all kinds of black bits and debris that got to that glass filter, and not beyond.

I will install the same type on my new one before the test drive.

This Q'jet carb has an internal paper filter, which was clean, but I actually have plenty of room for an external filter, AND i just ran across a new unused one in the junk drawer- so I'll probably stick it on there.

talbott357 · 05-18-2015, 07:59 PM

You might go ahead and replace the vacuum lines when you get a chance. I did all the ones on my 86 Pace Arrow 454, every one of them was degraded and flaking apart inside and out. It takes a little time, but it was worth the effort.

MotorPro · 05-19-2015, 05:01 AM

Sounds like your needle was stuck and you shook it loose.

Franka548 · 05-19-2015, 05:48 AM

HoneyBadger,
Glad that you got it going again. I agree with talbott357, I would replace all the vacuum lines, the rubber does deteriorate.
Frank

BA-in-Mich · 05-19-2015, 07:24 PM

Now that you got that going, check the weights in the distributor and make sure they are free to move and not gummed up.

HoneyBadger · 05-20-2015, 05:44 PM

The rig is currently sitting at the mechanic's down the road- waiting to get a new passenger side exhaust manifold put on. He is taking it slow as far as soaking the bolts with penetrant, hopefully he won't break any off

He's going to fine-tune the timing while he's got it there; I'll ask him to check the weights.

Miramichi · 05-20-2015, 06:49 PM

Having had several big block cars and several of them with quadrajets, they are a great carb, when working properly.

I would recommend finding yourself a Holley. A 650 should be fine. Dare I say even an edlebrock would be ok and far less adjustable, which would be best for you it seems.

Just read the second page lol. Glad you got it going! That darn ethanol, try to keep away from it!