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thenewkid64 · 12-31-2002, 09:38 AM

I need to know if this is normal.

Engine starts fine, runs normal, can drive it for hours no problem. But after I shut it down, about 5 min. later all I can smell is gas fumes in the coach.

The engine is equipped with a quadrajet carb, that looks like it is not the original, the motor is a 1975 454 engine.

I have pulled the aircleaner and run the engine to operating temps, cleaned the carb with a spray cleaner and what I saw happen 2-3 Min. after shut down has me concerned.

There is raw fuel dripping from the left(from the front) inlet on to the throttle plate. Due to the engine temps the fuel is vaporizing into a fine mist and then escaping the carb. Is this normal????

It seems to be getting worse (smells stronger) over the last year. Am I due for a new carb??? rebuild it??

HELP!!!!

TIA

qqq · 12-31-2002, 10:18 AM

Keep your fire extinguisher close

qqq

74Argosy24MH · 12-31-2002, 10:33 AM

It is not right. There are nozzles that the fuel is sucked from when the vacuum of the engine is present, a gasket 3/8" below the top of the carb. It could be coming form either one of these, but if the carb was right the fuel should not be that high in the float bowl to start. Rebuild or replace time.

John

thenewkid64 · 12-31-2002, 12:20 PM

Two more questions.

How much $$ to replace is normal?

Is there a web or mail order place that someone can reccomend?

Is this the type of thing a shadetree like myself can do, or will it require special tools to get the jets set correctly?

That was 3 questions, oops.

Or if it is a float issue that the fuel level is too high in the bowl can I just adjust the max float level?

74Argosy24MH · 12-31-2002, 12:50 PM

So I get to answer 2 out of 3, my choice?

Any of the hot rod books will have the best cross section of prices. I got most of my parts from Performance Automotive Warehouse when I did my engine, they had the best prices.

Fuel control in a quadrajet is metering rods, they dangle from the top of the carb and when reassembling, have to go into recesses in the casting. These are a little tricky but not bad. The float is not externally adjustable. I would try it myself. Get a rebuild kit and a gallon of carb cleaner (maybe a new float, the old foam ones tend to fall apart, see what you have when it is apart). It is not all that hard.

John

PeterH-350LE · 01-01-2003, 08:42 AM

Brett,
throw it out, soon! You have an accelerated problem with the needles valves which can not be rebuild. Its a very common problem with the old quadrajets. Another sympton of this problem is hard starting due to all the fuel leaking out of the bowls.
Get an Edelbrock!

thenewkid64 · 01-01-2003, 08:59 AM

Looking at the carb, it looks like it may not be original. There is a thin steel plate under it and the carb is fairly clean compared to the rest of the motor. I have not had and issues regarding hard starts as of yet, but the PO had just put a new fuel pump on 2 months before I bought it.

After doing a little research i see that new Edelbrocks run $600.00 factory fresh. I was going to go get a hot rod magazine to see what is offered. Any sources that someone can reccomend would be appreciated. I want to do a low modification swap. Meaning I want to do the labor myself, and I do not want to change the intke manifold. I have not doen a carb before, but I figure if I R&R it and can at least get it to start I can always take it to my mechanic to have the carb fine tuned.

PeterH-350LE · 01-01-2003, 09:22 AM

There a different types of adapter plates available for the Edelbrock, no need to change the intake manifold. You also want to go the electric choke route, getting rid of the problems of the mechnical choke.
Adjusting Edelbrock carb is fun and easy. It has been a while since I did it, but if I recall it correctly it was something like 1/2 turn out after max rpm.

74Argosy24MH · 01-01-2003, 10:22 AM

There should be a needle and seat for the float in the rebuild kit. But I don't know if I would bother after finding this. How about $275 for a brand new polished Edelbrock? Go to Summit Racing and paste EDL-1411 in part # search. It would cost $75 to rebuild the quadrajet and you still have the old casting and any problems you might find in it. Or try PAW you can get a catolog from them for $9. 2 years ago it was $5 and they refunded it on the first order, so I wouldn't guess on their prices now.

John

thenewkid64 · 01-01-2003, 11:11 AM

Thanks for the links. I have been surfing the Summit site and had not found the model you referenced. I found the ID number stamped on the side of the carb itself and based on the model that is there it looks like it will require a 795 CFM replacement. The direct replacement is a Eldebrock 1903.

I have not had any problems with the hot air style choke other that I need to release it vs it auto releasing.

Do I need an electric choke? What would need to be added, just a 12 Volt feed that is on with the ignition?

Based on the number on the carb I belive it not be the original. I also found a decoder so I could know what the numbers mean. The manufacture date on the carb is 1976, but the engine tag on the air cleaner says built in 75. And the carb was manufactured on the 1st of sept. in 1976.

Maybe the reason I do not seem to be lacking power is the larger bore?? I also have no emissions stuff other than EGR.

I plan on calling Summit tommrow and giving them the number off the carb as I cannot find an exact reference to the one I have, just the proper range, but it looks like the 1903 is what I need.

74Argosy24MH · 01-01-2003, 11:57 AM

If they want a lot more for the bigger carb I wouldn't do it. At 4000 rpm a 454 uses 525 cfm of air. I thought of a 600 at first, but that would be pretty anemic on acceleration and these big beasts are slow enough already. You really want the air to move through as fast as possible. It picks up and mixes the gas better, the stock flat manifold won't flow that much anyway.

The dates on the carb and air cleaner don't mean a whole lot from that period and time of year. Material didn't move through like it does now, trailer to assembly line. Parts got shoved everywhere and turned up months later. Model year change didn't mean much then unless it was also an engineering change.

The electric choke I would go for over vacuum. Hoses don't last all that long and when they leak they not only screw up your choke but lean out the mixture. Holley uses a single wire hookup, Edelbrock I would guess is the same, but I'll leave that for Peter.

You know if you get a nice new shiny polished carb you are going to have to clean up the top of your engine. If you wouldn't have mismatched compartment locks I know you won't be able to look at a shiny carb on top of a bunch of gunk.

John

PeterH-350LE · 01-01-2003, 01:03 PM

I used the 600cfm on a 350 before, which was perfect. Not sure if you need 795 for the 454, but would be interested to know.
Single wire to ignition for the choke.

TRAPEZE · 01-02-2003, 08:05 AM

If you want the electric choke, then I believe the model you are looking for is the EDL-1906. Brand new it is $420.00 at Pace parts,

http://www.paceparts.com/product.asp?3=1354

and $460.00 at Summit

http://store.summitracing.com/partdetail.asp?part=23426

The factory rebuild of the EDL-1903, hot air choke, will cost $360.00 at Summit, its part changes because it is a rebuild, it is number EDL-9973

http://store.summitracing.com/partdetail.asp?part=13993

My unit came with a Holly pro injection system. It has a throttle body with electronically controlled injectors that are very adjustable. An O2 sensor is installed in the exhaust system to tell you if you are running lean or rich, the adjustment to the injectors is on the dash and allows for adjustment of the choke, idle, acceleration, main and high RPM. It seems to work well for my unit. I do not know the cost, as it came with the MH.

Good luck, let us know how it works out.

Scott

Silver Bullet · 01-02-2003, 07:56 PM

I use the Edelbrock 1407 on my 460 (bored .060 over) and love it. The motor is basically a 473 cid, 9.0 compression. It's a 750 cfm with an electric choke kit. I installed this carb 11 years ago this April. I have had no problems with it what-so-ever, keep it clean and tuned and you will have no problems with it. Oscar
PS Get the Rod, Jet and Spring kit so you can fine tune it to your alltitude.

thenewkid64 · 01-03-2003, 03:18 AM

Thanks for all of the links and suggestions. They have been a great heat help.

I ordered the 1903 last night. Well it is a factory refurb 1903 so they call it a 9973. I decided to stay with the hot air style choke as it is what I am used to. The funny thing is that the model number stamped on my carb does not have a direct match in Eldebrocks list. I spoke to there tech guy and he said that is a rare occurance.

I mostly run in Florida so I am at sea level. I would assume (Bad word) that the carb will be set up for operation from sea level to a 1000~ ft.

We have a rally we are attending on Jan 16-19th so I will need to get it installed ASAP. I am sure I will have more questions as this is my first time doing a carb replacement.

thenewkid64 · 01-26-2003, 09:39 AM

Update:

The carb I initally ordered was not the right model. I ordered the hot air choke model and I needed the divorced choke model. I ended up sending it back, and getting the electric choke model. It arrived on Fri. and I have not yet had the chance to get greasy.

Looking at pre install I have two questions.

In previous posts it is mentioned to feed 12 VDC to the electric choke. Do I need to be concerned with cutting off the current to the choke feed to stop it?

The current carb has the fuel line going straight into the front of it, the new one is pointing toward the passenger side of the motor. So do I need to look for a new line to connect it or just cut the old line with a tubing cutter and mend it with gas line and clamps?

BTW I went with the 795CFM as a number of online calculators said I needed 700+ CFM for best performance.

Thanks for all of your sage advice on this.

74Argosy24MH · 01-26-2003, 10:25 AM

Run the 12v off ignition, the choke will only use it when it needs it. The gas line is probably double flared, about all you can do is use a short piece of rubber line and a brass barb (good time to stick one of the cheapy clear inline fuel filters in too).

John

thenewkid64 · 01-26-2003, 03:08 PM

John,

My toughts exactly on the filter if I am going to reroute it with a flexible gas line.

Thanks for the reassurance, I will start on the project this week!

BTW my dear wife informed me this afternoon she wants new flooring in the MH in time for the sarasota rally! Feb 17-23rd!!!!!!!!!! I have not even figured out hw much plywood I need to replace yet!! I think I am going to thave to tell her to hold on. I will try to have it done before mystic springs.

I have to replace the water heater before sarasota as ours works on 120V Only. I ordered a new one today.

74Argosy24MH · 01-26-2003, 06:16 PM

One other thought for you- there are insulators you can put under the carb, about 1/4" thick that do a good job of keeping the heat out of it. You will probably need longer studs. The mainfolds on these are pretty flat, but check your clearance on the engine cover.

John

thenewkid64 · 01-26-2003, 06:31 PM

This carb came packaged with some type of insulator plate. I was planning on installing it to help with heat transfer. I am also gonig to take a page out of your book and get the intake air nozzle extended to a point in front of the radiator to try to draw in cooler air.