Billb442

I am having an issue with my 69 442 running extremely rich and having a hard time starting after sitting a while. I had the carb rebuilt a while ago and just got around to installing it. It takes a while of cranking to start and smells of gas really bad once it does. I can turn the idle screws all the way in while running and it has no effect on the engine.
After sitting a couple of days I pulled the carb off. When I disconnected the fuel line from carb I noticed no gas came out at all. Then I removed the fuel line from the fuel pump end and again no gas came out. None.
I then removed the top of the carb and there was very little gas in the float bowl. The float did not appear to be stuck but the level of the gas in the float seems lower that the fuel inlet valve. The inside of the intake manifold is wet. I called the carb guy and he said it sounds like a bad fuel pump. Possibly to high of pressure to the carb causing it to flood.
From what I just read, the fuel pump I bought Airtex can have issues.
Any thoughts?
Bill

pcard

Bill - did you have these problems before installing the new carb?

Billb442

As far as I recall it was running OK. The car has been in process of being restored for many years now and it hasn't really been running in quite a few years. So it was sitting for a while with gas in the carb which is why I had it rebuilt figuring it might be gunked up with dried up gas.
I also replaced the fuel pump at the same time as the old one wasn't pumping any gas. I replaced it with a cheap Airtex pump and it seemed to pump OK but now I am having the issue described. So I'm not sure if it is the carb or fuel pump or both that is causing the issue.
The carb guy said he checks all the components thoroughly when rebuilding it and he said he fixed the common issue of the main well plugs leaking. He offered to tear it down and look it over for any issues so I am bringing the carb to him on Friday.
So I am trying to figure out if I possibly need a new fuel pump at this point. Is it possible for it to put out to much pressure and blow fuel past the float needle and flood the engine? Also isn't there supposed to be a check valve in the fuel pump that stops fuel from leaking back to the tank?
Bill

rjohnson442

pull the hose off at the carb and stick it in a bucket and have someone crank the motor over for you. If gas shoots out into the bucket the pump is fine. My bet is the floats are soaked or the needle isn't seating. For about 7 bucks you can put a fuel pressure gauge between the pump and carb and eliminate the pump as the problem. post back with the psi results.

brown7373

If you crank it with the line disconnected from the carb and no gas came out it would seem like the pump either defective or not getting fuel from the tank. What pressure is the pump supposed to put out. Carbs take a lot less than later model fuel injected cars.

Billb442

I know that it is pumping gas as I did exactly as you suggested when I installed the pump to make sure it was pumping. I did not check the pressure though so I guess I need to get a fuel pressure gauge and check that tonight when I get home. Should the fuel be draining back down the line though? That doesn't seem right to me.
Bill

MDchanic

Bill, you are describing two separate problems.

In one, you are not getting gas to the carburetor, the float bowl level is low, etc.
In the other, you are getting too much fuel, and the engine is running rich.

They really aren't very compatible with each other.

If you have any cracks in rubber hoses or pinholes in steel lines between the tank and the pump, your fuel can leak down, and be hard to pull up, especially when first starting after a few days, giving half of the exact symptoms that you describe.
If this were the case, though, once the pump pulled gas from the tank, the car would run fine, maybe feeling a bit weak at full throttle or at high speeds.

If the fuel pump were pushing too much pressure past the needle valve, then you could run rich, but usually very rich, so that it essentially won't run, and especially won't idle.
If you removed the airhorn, you would see too much fuel in the float bowl, not too little.

You need to find out what was done to this carburetor when it was rebuilt - were any jets or needles changed? Was anything else changed?

I agree that measuring the fuel pressure and the volume pumped in a minute, as per the specs in the Chassis Service Manual, is a good place to start, but I think all that will do is prove that your fuel pump is fine, so that you can then begin to go after the real problem.


Also, if your car is a '69, as you say, those carburetors did not have problems with leaking well plugs.
If your rebuilder thinks they do, I would question his abilities.

- Eric

Billb442

Eric, thanks for the response. Let me clarify a little the symptoms I am having.


I believe that I am getting gas to the carb just fine as I had tested the pump when I installed it. The problem is after it has been sitting for a day or two the fuel has leaked back down the lines and takes a while when trying to start the car again because the pump has to pump the fuel back to the carb. Once the fuel gets pumped back up the car starts and runs but runs extremely rich. The idle screws have no effect on anything.



The other issue appears to be that the carb may be leaking fuel as the float bowl was low when I took the top of the carb off. Understand that I took this off days after the last time it was started not immediately after. I would imagine that if I took it off right after starting it the bowl would have been full. Otherwise I don't know how it would be running so rich. Also when I pulled the carb off the intake it was wet down inside there as if it was leaking gas.


As far as the rebuild goes. This carb was a reman quadrajet that I bought a while ago. It is going on a W30 engine so I gave the carb guy the specs for the W30 carb. Whether or not he followed those specs and changed anything or not I don't know. I will ask him when I bring him the carb on Friday.
Bill

Fun71

Have you checked the fuel pressure? QJets like 7psi max, so if your fuel pump is putting out more that that the fuel bowl could be overfilling.

Several years ago I went through 3 different new Carter fuel pumps from the parts store and they all pegged my pressure gauge at 10 psi. I finally gave up and put a pressure regulator on it.

edit: I shouldn't have said 7psi max, I should have said greater than 7 psi can cause issues.

Billb442

No, I have not checked the pressure yet. I am planning on doing that tonight. I'll post what the pressure was after I test it.
Bill

Billb442

OK, I rented a fuel pressure gauge from autozone last night to check the fuel pressure. Unfortunately they only had one made for fuel injection systems so the gauge is designed to read high pressure. I don't know how accurate they are at the low end but I tried it anyway. I had to rig it up with various hoses and clamps to get it to work but I think I got a good seal as no gas was leaking out. The first number on the gauge is 10 and it has a few tick marks between it and 0. I cranked the engine and the needle settled somewhere in the middle of 0 and 10 maybe a little above middle. So it "appears" to be putting out correct pressure if we can believe the gauge.
So I guess that leaves the carb as the culprit? I'll have to wait and see what I find when I bring it back to the carb guy on Friday.
I would still like to know though is it normal for the gas to drain back from the carb to the tank when the engine is turned off? My fuel pump does have a fuel return line but I don't know if it is supposed to allow fuel to always return or only under certain conditions.
Bill

MDchanic

It is not normal for the fuel to drain back to the tank unless there is an air leak in the line between the tank and the pump.

The fuel may evaporate from the carb (it gets kinda hot), but should not leak out, and cannot drain back (the fuel entry is at the top).
To check for leakage, just pull the carb and fill the float bowl with acetone or something similarly volatile and thin (no float or fuel pump plunger inside after you've removed the airhorn) and watch the bottom. If there's a leak, it'll start dripping right out.

As for pressure, a fuel injection gauge is the wrong instrument.
All you need is a standard diagnostic vacuum gauge. They all (as far as I've seen) read backward as fuel pressure gauges, and are much easier to hook up.

- Eric

brown7373

If the fuel pump checks out as somewhere under 10psi, and when it starts it runs rich, I would suspect the carb. Just because it was rebuilt by a "carb guy" doesn't mean it is right. What jets and primary rods did he use? A lot of carb kits sold in parts stores are junk, and deteriorate rapidly with ethanol and other additives in the fuel, which causes them to leak, run rich and destroy rubber parts in the carb.


If the float bowl is low, it could be a low float and it could be evaporation. Flooding could be from a needle and seat that leaks or a gas soaked float that sinks. If it were me, I'd check the jets and primary rods, call Cliff and order a kit and correct jets and rods if needed. He can help you select the right ones for you application. www.cliffshighperformance.com

Billb442

Eric, thanks for the reply. Actually now that I think about it I don't know if the gas is leaking ALL the way back to the tank but it is definitely leaking back from the carb to at least the fuel pump as the fuel line was completely dry when I took it off. Is that at least normal? If not does that indicate a problem with the fuel pump?


I will try filling the float bowl tonight and see what happens.


I understand the fuel injection gauge is not correct but that's all they said they had and I figured it would at least give me a ballpark reading. I will look for a vacuum gauge that has a fuel pressure meter on it and give it another try.
Bill

caddy

Start with cheap fix first, check the fuel lines at the tank... I had a similar problem with fuel not being where it should be if I let the car sit for awhile... Tank hoses were dry rotted, but, would get fuel to the carb when pumped...

Billb442

I'm not sure what jets or rods he used. I gave him the specs for a W30 carb and asked him to rebuild it as such. Whether he did that or not I'm not sure. But he offered to tear the carb apart of Friday and take a look so I will take note of what parts he put in and go from there.
Bill

Fun71

Back when I worked at some parts stores in college there were two styles of paper fuel filters that fit into the carb inlet: one had a check valve to prevent gas from leaking back and the other one didn't. You could try installing one of the filters with the check valve to see if that does anything for you.

FYI, the carb on my car goes dry after sitting for a few days. I have to crank it over for a bit (20 seconds or more) until the float bowl fills up before the engine will start. This doesn't happen when I drive it every day; just when it sits for 3-4 days or so.

MDchanic

The still do. These can help a bit with "fuel drainback" problems sometimes, presumably by limiting air entry at the top of the line (fuel shouldn't be getting in, as it drops down into the float bowl from the outlet).

- Eric

Koda

Eric, could you clarify why you said the 69 quadrajet does not have the leaking plugs issue?

Billb442

Thanks, I will look and see if I can find one of those filters. OK, so maybe my bowl being low was just evaporation? It was a few days before I pulled it off. I just wouldn't think that much gas would evaporate that quickly.
Bill

MDchanic

Yes. If you listen to the authorities (like Cliff Ruggles), they will tell you that the leaking plug problem was essentially limited to the '66 and '67 models, which had different plugs (driven-in, I believe), and was cured by changing to spun-in plugs around '68.

Certainly, it is possible for the later plugs to leak, but it is not a "common problem" as some like to say, and does not to be routinely "corrected" in non-affected carb models.

If there's evidence of an active problem, that's a different story, but that's easy enough to check.

- Eric

brown7373

Changing the filter will not address the running rich, and maybe not hared starting. Does it have a correctly operating choke? Those filters were not designed for our cars. I think normal evaporation is much more likely. I have 3 Q-jet equipped 70-72 cars, and numerous before them. They ALL started after depressing the accelerator once and turning the key. Maybe if one sat a month or 2 it would take 15 or 20 seconds, but they always start. You aren't pumping the accelerator while cranking, are you?


I'd check the jetting, the float level and all adjustments, including and especially the choke. The kits from Cliff include rubber parts impervious to ethanol, gaskets that insulate better from heat, and they include a new float, also impervious to ethanol.

TripDeuces

Fuel can't flow back to the tank from the fuel bowl because the needle and seat is higher than the fuel inlet. If the bowl is going dry it's probably going out the fuel well plugs which will certainly give you a rich condition. I have to wonder if the rebuilder sealed those well plugs.

Billb442

As far as I can tell the choke is working. It is the disconnected mechanical type that works off the heat of the intake. It is closed when cold and opens as the engine warms up. Whether or not it is opening at the proper rate I don't know but it does fully open when warm. I do pump the accelerator once to set the choke but after a while of cranking when it finally does start to run I do have to hold the gas pedal down slightly or it will stall. Even as I do this it runs very rough for about a min, as if its not running on all cylinders, but I think it could be because of excess gas possibly leaking into the intake. Not sure about that though. Once it has been running for a little while it idles fine but still smells really rich out the exhaust.
I will have the jets and float and all that checked on Friday and will post back the findings.
Bill

Billb442

OK, so I got a proper vacuum/fuel pressure gauge and connected it directly to the fuel pump. I cranked the engine for several seconds and watched the gauge. It registered around 7 psi but would pulse up to around 8.5-9 psi as the fuel pump would pump. When I stopped cranking the engine it quickly returned to 0 psi. Is all this within spec?


I also put the carb over a bucket and filled the float bowl to check for leakage. After a couple hours I did not see any leakage under the carb. I checked the float bowl adjustment and it was spot on at 1/4" which is what the service manual says it should be. So I guess I will wait until tomorrow and have the carb guy pull it all apart and find out what jets and rods he used.
Bill

MDchanic

According to the CSM, fuel pump pressures should be a constant 5-6psi at idle, so if you've got 9, that may be your problem.

I'm not surprised that the carb didn't leak.

- Eric

Billb442

Well I'm thinking I should probably replace my fuel pump to be on the safe side. Anyone know of a good source for a good quality fuel pump? Most I have looked into don't say who the manufacture of the pump is.
Bill

pcard

I bought mine at Inline Tube.

Fun71

NAPA carries Carter fuel pumps and a lot of the other parts stores carry either Carter or Airtex. I think both are good quality pumps. If you want to know who the manufacturer is, just ask the parts salesman at your local auto parts store and he will tell you.

Billb442

Well I have Airtex now so I guess I will try and find a Carter one and see how that goes. You said you had issues with Carter pumps too though. Are those the only 2 options now? Where did you get the regulator from?
Bill

Billb442

Update: I took the carb to the carb guy who rebuilt it a while ago. He tore the whole thing down right in front of me. He blew air through all the passages and none of them were blocked. He checked the float height and it was fine. He checked all the needles and rods, they all looked good and the correct size. He put it all back together and hooked up a electric fuel pump that puts out 6.5psi. He left it on for a while and checked for any leaks. There weren't any. So it seems like they carb is fine.

I received a new Carter M4516 fuel pump that I ordered and installed it last night. hooked up the pressure gauge and cranked the engine a bit. The pressure now reads 9.5-10.5!!! So its actually worse than the Airtex one I had in there. Ugh! I don't get it. According to the specs this is supposed to be rated at 5.5-6.5psi. How is it pumping 10psi?

Maybe I am doing something wrong? According to the Service Manual the engine is supposed to be idling on the gas still in the float bowl. I was just cranking the engine without starting it. Does it matter if it is idling vs just cranking? Also the manual says the fuel return line should be plugged. When I tested it the return line was hooked up as normal. Would this cause the pressure to be high? One other thing to note. The fuel line out of the pump is 3/8 but the pressure gauge line is smaller. So I had to basically put the gauge line inside the 3/8" line. Could this downsizing of the line cause the pressure to read that high?
Bill

Fun71

You aren't doing anything wrong, it's an issue with the pump itself.

That's about the same thing I went through with fuel pumps several years ago - three different pumps put out 10+ PSI. Quality control is apparently out the window and the pumps are not being built or adjusted correctly. I bought a basic Holley (I think) regulator from a member on ROP to get around the problem. I never had this issue back in the 80s and 90s.

My2nd 69 442

Billb442. You have a beautiful car. I had on almost exactly like your photo when I was much younger and I currently have one without the vinyl top.
I have read this post with interest due to having the near same 1st start of the day. I've been using a small squirt of carb cleaner for my 1st start after that it starts fine. I have a carb kit on order but I have doubts of the carb kit fixing anything.
Have you found an actual fix for your issue?

My2nd 69 442

Ops. I just now see that this post is several years old.