Carb mounting

For all Carb and Injection engines, standard or modified plus non-standard engine transplants. Heads; Blocks; Cooling (including heater issues related to the cooling system); Mounts etc

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Nutty
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Carb mounting

Post by Nutty » Fri May 15, 2020 6:54 pm

Hi all, just a quick one, I have changed the carburettor flange for a brand new one, part no 026 129 761E however the carb, pierburg E2E, is very loose on the flange, I mean the bolts are tight torqued up to the manual but the whole carb moves and inch or so from side to side, is this normal? I have read on the forum that a leaking flange can cause all sorts of spurious idling problems and believe me I have idling problems, too low, seems to be running on 3 cylinders at times, have done timing, Timing belt (will triple check)new sparks, coil is fine, leads fine, good spark, will do compression test in the morning


The first tool invented was a hammer, the second a bigger hammer

GT_II
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Location: Warwickshire

Re: Carb mounting

Post by GT_II » Fri May 15, 2020 8:01 pm

The flange comprises two metal plates partially encased in a rubber moulding which allows movement between the two plates. The lower plate is rigidly mounted and sealed to the inlet manifold and the upper plate is rigidly mounted and sealed to the carburettor body. Any leaks are usually caused by a crack in the rubber between the two plates.

So the flange assembly does allow some flexibility, but the movement should be between the lower and upper plates of the flange, not between the carb and the flange or between the flange and the manifold.



Nutty
Posts: 22
Joined: Mon Jan 20, 2020 8:56 pm
fill in the right answer: 15

Re: Carb mounting

Post by Nutty » Fri May 15, 2020 8:18 pm

Thank you for your reply, I did fit the old flange to another carb, the rubber is much stiffer and there is much less movement in the carb, the bottom plate is solid on the manifold and the top plate is solid on the carb, will replace for the old one tomorrow and see what happens.


The first tool invented was a hammer, the second a bigger hammer

Nutty
Posts: 22
Joined: Mon Jan 20, 2020 8:56 pm
fill in the right answer: 15

Re: Carb mounting

Post by Nutty » Sat May 16, 2020 10:53 am

Well, compression test done, 1, 13.5bar, 2, 12bar, 3, 9bar, 4, 14bar, wet test 1, 15bar, 2, 13bar, 3, 10bar, 4, 15bar. Seems no 3 cylinder is on the dodgy side, test carb mounting next.


The first tool invented was a hammer, the second a bigger hammer

mark1gls
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Location: Somerset

Re: Carb mounting

Post by mark1gls » Sat May 16, 2020 3:52 pm

Yes bit of a drop in cylinder 3...

Make sure you have the bracket on the front to hold the air box as it’s often missing or fixing on air box broken and without the bracket the carb and air box wobble about and split the rubber mount.


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Nutty
Posts: 22
Joined: Mon Jan 20, 2020 8:56 pm
fill in the right answer: 15

Re: Carb mounting

Post by Nutty » Sat May 16, 2020 10:39 pm

The bracket is present and correct, I just assume the modern rubber flange is of a different consistency than the old one, call it progress..


The first tool invented was a hammer, the second a bigger hammer