Engine not running right
- Thread starter johng
- Start date
Roscobbc
Moderator
John - what is your carb? - Quadrajet, Holley (or perhaps Edelbrock) - If its a Quadrajet it'll have a dual plane spreadbore manifold like the one Oneball showed in previous post. I'd be very inclined to accept Andy's offer to borrow his Quadrajet (if that's what your carb is) if only to eliminate (or otherwise) a carb issue.
johng
CCCUK Member
Good news and not so good news. Put the carb back on the engine and it now runs fine 
. However I noticed when taking the carb off there was a slight weep of fuel from the filter housing. Having put it back together there is still a slight weep. Is there meant to be a seal between the carb body and filter housing? I don't have one. Exhaust temperatures are now all pretty much the same.
. However I noticed when taking the carb off there was a slight weep of fuel from the filter housing. Having put it back together there is still a slight weep. Is there meant to be a seal between the carb body and filter housing? I don't have one. Exhaust temperatures are now all pretty much the same.
Roscobbc
Moderator
John - there are USA specialists who offer re-manufactured Quadrajets - they ain't cheap (especially when adding the shipping costs etc) but unless you swap the inlet manifold and use a 'square bore' carb (which again ain't cheap) - or - source a Holley spreadbore carb to match your existing inlet you're kinda stuffed. Quadrajets are great carbs when working properly.
antijam
CCCUK Member
I had running problems on my '71 that were fuel related. A rebuild of the carb (not the original but a Quadrajet that had been fitted from a later car) and a lot of faffing about didn't sort things out, so in desperation I bought a professionally rebuilt Quad' - of the correct year - from a dealer in the States and after some rejetting to compensate for the deviations of my car from stock, the car now runs perfectly.
It wasn't cheap - the best part of £1k with all the shipping and tax charges - but it certainly solved my problems.
teamzr1
Supporting vendor
If this helps
New Quadrajet and Rochester carbs, rebuild kits and repair parts
New Quadrajet and Rochester carbs, rebuild kits and repair parts
johng
CCCUK Member
Some of those carbs on Amazon look surprisingly cheap, but fortunately all I need now for a properly working Quadrajet is a 1" nylon seal to go in the filter housing. The only outstanding question is what was it that blocked one of my passage ways. The filter looks clean and so did the inside of the carb. Hopefully I haven't got water in my tank.
antijam
CCCUK Member
Those carbs listed on Amazon are not genuine Rochester Quadrajets but Chinese knock-off 'compatibles' - which is why they're cheap. I'm not saying they're necessarily inferior but as ever, you get what you pay for.
johng
CCCUK Member
A bit of a disappointment today. Went to a car meet with my son and all was well on the way there, but on the way back I've got the same symptoms again. Ticks over fine, goes if I floor it, but feels like it's running on less than 8 cylinders at part throttle. I guess I need to strip and clean the carb again, but the question is why? I did fit a new filter after the last episode, I'm thinking maybe it's water in my fuel.
Roscobbc
Moderator
Try a gravity fed slave tank?
johng
CCCUK Member
Could be, I did have a problem a couple of years ago with the carb mounting bolts coming loose, but then I'd expect the tickover to drop. I'll check they are tight and if so I'll try cleaning the carb out again. Trouble is even if that cures the problem it will presumably just happen again at some point.
johng
CCCUK Member
I'm going to need a fairly large tank to get to Wednesday's meeting Ross
Oneball
CCCUK Member
Could be the carb base or manifold isn’t flat. Piece of float glass and some emery.
johng
CCCUK Member
I don't think there is a flatness problem as the car has been running fine for several years. The only time I've had a problem has been when the bolts came loose (and then the issue was it wouldn't tick over) and last time when cleaning the carb fixed the issue. I imagine that the fault is the same again now and cleaning the carb will fix it, but how do I prevent re-occurence? Presumably the carb filter should stop dirt getting in, but what about water, will that go through the filter? Typically I've currently got almost a full tank, so flushing it is not easy.