The Dodge Challenger Message Board

Hello, i fired up th3 360 today, hoping for a drive. It was running very rough. I took the aircleaner off and there was wet fuel under the lid and around the top of the carby. This TQ is new. That is, it is fully rebuilt and the guy who does them is a TQ fanatic. Anyway, i started it again without the aircleaner and was able to see it through the windscreen. Within a few seconds i could see fuel bubbling up through the front air tube! I had a look down and it was liquid fuel about 1cm thick in the secondaries.

I could not get through to the fellow who rebuilt it but rang another fellow who is clued up on them. He said one of the floats was sticking up, or, if it had the brass floats, one of them might have a pinhole and was filling with fuel, keeping the inlet valve fully open. I have since pulled it off turned it upside down and poured the fuel out through the top. There was a large amount of rubbish in the fuel! Lots of small gritty looking garbage. I filled it up with fuel through the inlet and poured it out again. Same deal. So i can only assume there is a lot of crud getting through. The filter is on the other side of the pump. I am just about to put in a second filter AFTER the pump. Unfortunately it does not have that very fine mesh inline filter inside the inlet, so i think i should get one of those. I am about to pull the top off the carb and have a look. Dave, or anyone if this has happened to you, what did you do? IS there any pointers you can tell me to prepare me for my excursion into the depths of the TQ fuel bowel? Thanks very much. steve

well, have taken the top cover off. Its as i thought, new and spotlessly clean inside. The floats are the older brass ones that he has repaired with tin and solder but have not had fuel inside them, they appear to be working properly but tomorrow will clean and blow the seats with air and test them. Probably just some grit holding the inlet valve open. There was plenty of grit in there. Lot of trouble to go to just for a near microscopic bit of dirt.

Man,, it's been a lot of years since I worked on those. They would eventually warp/crack the 'plastic' fuel bowls during our weather extremes. There is a particular O-Ring on the ThermoQuad that must be present or else it will flood as you described but I cant remember where it was located.

Hey there Eddie, i think you mean these ones in the picture. I did check them first, but i don't think they would cause huge flooding like this. This was definitely caused by one of the float bowl needle/seat staying open and fuel from pump pressure pouring in. I checked and cleaned them both. Everything new, so should be no problem but i was a bit worried about the top cover gasket. The float bowls seem to come very close to some of the surplus gasket edge. If this edge was turned down slightly they would definitely interfere with the float bowl rising all the way up and closing off the needle and seat valve. So i pulled the gasket out and trimmed that area out so there is no chance of that happening. Putting back in soon, will let tell how it went.

I had this happen with a Edelbrock Performer carb. Ran like a pig for a week but after blowing air through it and refilling the fuel tank it ran perfect again. Must just have been some crap in the fuel.

Yep, thats the one Steve. Hope your gasket modification helps.

Thanks, i finally got in contact with the fellow, it was a long weekend in Sydney (Australia: the Land of Public Holidays!). He was baffled, had never seen it happen. Said a hole in the float can do that, other than that could have been the load of crud in the fuel that i described. Carb all back on now, but before i connected the fuel line, i took a sample of fuel from the line by cranking it over. Still lots of grit coming through even with 2 filters!.. So i am not connecting that up yet. The fuel tank is freshly cleaned, must be a rusty fuel line i'd say. So its off to get one of those expensive cartridge fuel filters with the sintered metal element that you can flush out and reuse. The fuel line can STAY there. All for now.

Sometimes you get a lot of crap in the fuel from the petrol station when their storage tanks are getting low.
The fuel is always better just after they have topped their tanks up.

The worse thing you can do is to get fuel at the fueling station while IT'S being filled up. (It stirs the sediment at the bottom of the tank,,and there is a lot of it in the bottom of those rusty steel tanks)

dave-r wrote:Sometimes you get a lot of crap in the fuel from the petrol station when their storage tanks are getting low.
The fuel is always better just after they have topped their tanks up.

Yes , thats what this fellow said too. We lose both ways. Superman wouldn't have a problem, he'd use his X-Ray Vision to see if the fuel station tanks were full. If they wern't, he'd drive somewhere else (in his Challenger of course)

airfuelEddie wrote:The worse thing you can do is to get fuel at the fueling station while IT'S being filled up. (It stirs the sediment at the bottom of the tank,,and there is a lot of it in the bottom of those rusty steel tanks)

That's a good point Ed, i hadn't thought of that. I'll remember that because i often see the tankers filling the vaults with cash, sorry, with petrol.

Sorry, in one of those moods tonight.

Whenever I fill my small gas can up at various filling stations around town I see there is a always a small amount of fine grit,sand, rust ect in the bottom of my container. I started asking around. Our tanks are made of steel, they even 'leach' fuel into the ground! This is perfectly acceptable. If you were putting in new tanks they must be a synthetic material, very expensive,,ect..but most are plain steel tanks that obviously corrode and the stations dont use or change filters. Lately, Steve I think I may be having the same problem. Sometimes my car 'loads' up very badly and runs very rough, blowing black smoke,(fuel), and acting like the needle&seat have the dirt problem as Dave had on his Carter AFB. Then after some hard running it runs fine. If it does it again, I am thinking of removing my Center carb and dis-assembling it for a good look-over and fresh gaskets. Damned Gas stations or petrol pumpers

yea the old ryco filterswork well i found those cintered bronze filters are shit they block to quick your better off without it if you use a good inline filter the cintered bronze 1s just block up all the time even if the fuel is clean enough not to be a problem foe a normal filter theyre just shit unless you need real fine filtering then why is what i want to khow ,any engine that actually needs to get some fuel has larger jets than any particles those super restrictive filter will allow
cheers ian

hey eddie thats always been a problem over here when ever ive drag raced ive goneout thr road & thrashed the crap out of it first a technic thyat works exceptionaly well with hemi 6s after a good flogging they idle over 1000rpm & run real hard my guess is pumped up lifter nothing to do with fuel but it does sort out any probblems
seems to work
cheers ian

Hi Ian - looks like you wrote those posts in a hurry (!) anyway, you are right, people are saying the sintered elements clog up very quickly. I just don't want all that crap and grit in the bottom of my new TQ fuel bowl. And i'm driving it to Sydney soon so the last thing i want on the Nullahbor is fuel problems due to poor filtration. Today i bought a Ryco EFI filter for BEFORE the pump. They filter down to 10 microns instead of 20+ microns for the carby filters. It was a metal can type. I also bought an inline glass type one for the line after the pump. It has a replaceable gauze type element - $20 at Auto One. Hopefully that will be good enough. The car fuel line is the only thing that would have crap and scaly rust in it due to the car sitting doing nothing for 5 years. I think after a few hundred miles of fuel flow that should diminish, then only have to worry about the fuel station fuel quality.

yea i was a bit pissed that night now that ive read what wrote its a bit garbbled
cheers ian

Shoulda told me, i would have "had a few" before i read it, then it woulda made perfect sense!

Anyway.... FOUND the cause of the flooding problem tonight. Unfortunately i didn't pick it up the first time i pulled the TQ apart. I put it all back together, onto the car, fired it up - SAME problem, fuel pouring in. Hopping mad. Off again and then finally discovered that one brass float was about 1/3 full of fuel! It was hardly noticeable in weight but only when i shook it. I weighed them both, the good one was 8 grams, the bad one was nearly 19g ! The fellow who built it is sending me two more tomorrow.

glad to hear you found the trouble steve
cheers ian