GT MK1 (carb) fuel pump

B-Hive · Post by **B-Hive** » Fri Sep 16, 2011 5:43 am

Just did an awesome coast circuit.. Canberra---coast---Sutherland---Canberra in the BX GT ...such a great animal on the open road...however I do believe that my fuel pump is on the way out , as on lively up hill overtaking manoeuvres the old girl would baulk and falter a pretty much lose all go...

Cut to the chase....does anyone know if a 1.6 mech fuel pump is the same/compatible with a 1.9..or is the !.9 higher flow?...

I ask this because on ebay UK there are a variety of pumps from 8 pounds to 25 pounds..one is claimed to suit a BX 1.9 and an LNA 1.1!!! looks different anyway..

Then theres a 1.9 GT pump for models 89-94????!!!

And then theres a 1.6 pump that i know would fit by the look of it but its maybe a lower volume pump... guess the cost isnt the biggest concern...just dont want to get the wrong part...

Thanks

Post by **Tim Leech** » Fri Sep 16, 2011 8:08 am

as far as i know on the UK ones they are the same?.

B-Hive · Post by **B-Hive** » Fri Sep 16, 2011 2:16 pm

Roverman wrote:as far as i know on the UK ones they are the same?.

Thanks I couldnt imagine there being any difference..

Post by **mat_fenwick** » Fri Sep 16, 2011 9:57 pm

Have you checked for other restrictions i.e. kinked pipes or a clogged fuel filter? Ironically one of the guys who did the BXagon with a 19GT had exactly this problem - the car had been laid up for a few years prior to the trip and although he'd changed the fuel filter before setting off, after a couple of thousand miles it was so clogged it was restricting the flow on full throttle up hills.

B-Hive · Post by **B-Hive** » Wed Oct 05, 2011 7:48 am

Thanks for input so far guys...but the problem persists

Have removed and checked fuel tank pickup..all okay

Replaced fuel filter and pump with new

Swapped out coil..

So problem of car hesitating and then bogging down and faultering really badly continues.. Straight line flat road giving it welly and all seems good ..

I have found a test road that can bring the problem on,, in involves a decent hill with some turns.. What I have found now though is that under load up hill ..all seems ok until I hit the first bend,, everytime.. And looking back on what I thought were other straight up-hills, the problem really only occured (i think) after I abruptly pulled out to overtake or to get back into left lane again.

So it would seem that the (carb) is affected by turning right or straightening up after fast left (similar physics)..

The last time it did it (unprovoked) it took a significant amount of time to "clear" itself..

It just occurred to me that the problem still could be the fuel pick up as the pick-up is situated on the right of the tank and near the front..

design fault??? or missing fuel baffle in tank or missing something or another on the pick up tube...

HHHMMM!!!

Thoughts??

citronut · Post by **citronut** » Wed Oct 05, 2011 8:53 am

have you had the lid of the carb to see if you have dirt/water in the float chambers,

regards malcolm

B-Hive · Post by **B-Hive** » Wed Oct 05, 2011 12:42 pm

citronut wrote:have you had the lid of the car to see if you have dirt/water in the float chambers,

regards malcolm

yeppers.. had it all opened up and cleaned out thoroughly

citronut · Post by **citronut** » Wed Oct 05, 2011 1:39 pm

2BXORNOT2BX wrote:
citronut wrote:have you had the lid of the carb to see if you have dirt/water in the float chambers,

regards malcolm
yeppers.. had it all opened up and cleaned out thoroughly

citronut · Post by **citronut** » Wed Oct 05, 2011 1:41 pm

whooops i must of clicke quote instead of headit (edit)

regards malcolm

B-Hive · Post by **B-Hive** » Sun Oct 09, 2011 12:47 pm

ok problem took a tangent, as carb decided to pick up air debris and prevent any proper running...removed barrel one air jet ..totally clogged..

cleaned that up but other issue still persists

All is good until i open up the second barrel then back off to the primary barrel...baulking stuttering, misfiring,,,,and then only eventually only just clearing itself..

when in total fault mode, if i floor it. all ok..so second barrel of carb helps and or compensates...first barrel flooded or whatever....

Pretty close to giving it to the local man and paying him for his "experience"

Post by **mat_fenwick** » Sun Oct 09, 2011 1:04 pm

Is the second barrel brought in simply by throttle position? I was wondering whether that is staying open when it should be closing (i.e. when you back off the throttle) making the mixture too rich when it should all be being controlled by the primary barrel. When you floor it and bring the second barrel into play again all is well...

When the problem occurs, if you kill the engine and quickly shift into neutral you will be able to examine the plugs and get an idea of what the mixture is like at that particular time. That may give a clue.

B-Hive · Post by **B-Hive** » Sun Oct 09, 2011 1:17 pm

mat_fenwick wrote:Is the second barrel brought in simply by throttle position? I was wondering whether that is staying open when it should be closing (i.e. when you back off the throttle) making the mixture too rich when it should all be being controlled by the primary barrel. When you floor it and bring the second barrel into play again all is well...

When the problem occurs, if you kill the engine and quickly shift into neutral you will be able to examine the plugs and get an idea of what the mixture is like at that particular time. That may give a clue.

thnx for your input mat...i think the problem is with the first barrel after use of the second barrel ..i have no idea why...i have had many many weber carb cars and never had a problem like this.... quite uncanny really...it seems to fllod when i press onto to the second barrel and then refuse to operate when I back off...carbs should not be this complicated!!!

citronut · Post by **citronut** » Sun Oct 09, 2011 1:42 pm

is the accelarator pump diaphragm working corectly and shooting a nice clean shot of fuel as you accelarate,

maybe the diaphragm is letting air passed

regards malcolm

Way2go · Post by **Way2go** » Sun Oct 09, 2011 3:20 pm

2BXORNOT2BX wrote:...i think the problem is with the first barrel after use of the second barrel ..i have no idea why..

Have you lubricated the linkage with a thin oil such as 3in1 ? Especially the axis rod for the second butterfly as this butterfly works under air demand, not by (direct) throttle position.
If this is not opening properly due sticking then you would have power loss and conversely if not closing properly on tick-over would result in this being high. If then fuelling and tick-over have been adjusted to try & compensate the revs, fuelling will be wrong when driving.

citronut · Post by **citronut** » Sun Oct 09, 2011 9:44 pm

the second choke butterfly is mechanicaly opend by a cam on the thtrotle linkage, but cant open till the choke mechanisum if fully off, as it is locked off till the choke is off,

regards malcolm

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GT MK1 (carb) fuel pump

GT MK1 (carb) fuel pump

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