Twin 40S Fitted, Won't Start

[theduck]

Ok so fitted my twin 40s to my 1600 pinto after sorting out the throttle linkage, however I can't get it to start. I assumed that the jetting and venturi sizes would at least run, but if they are well out (and judging by Venturi too small?) could they stop it starting completely? Venturi is 30 and I expect I need 34.

 

Or... My timing was set as a best guess to get the engine started on a weber 34ich and really needed final adjustment. Could this need tweaking instead or should it be good enough if it was good enough to run with the 34ich on?

 

I've managed a couple of what sound like almost starts but it dies almost immediately after letting off the starter

 

Thanks in advance.

 

Edit corrected typo

[Guest adamgreaves]

I've just installed twin 40s on my 2.0 pinto but unlike yours mine starts when the choke is open but once I put the choke in the engine stalls - im thinking I may have wrong size jets or something in

[Longboarder]

A couple of dabs on the throttle should enrichen via the acceleration jets, enough to start and repeated dabs will keep it going (unless the jets are way too small. Standard pinto 2.0l will run happily on 32mm venturi so that's not the problem. Starting just after you release the starter suggests you are loosing positive supply to the coil when cranking. Wiring fault or faulty ignition switch. As a temporary test run a live wire from battery positive to the coil positive so it has a definite supply and then try to start it. (You will have to pull this wire off after it's started to be able to stop the engine.)

 

Nigel

[theduck]

No it's not starting, I meant it seems to just about start while cranking, but then only runs for a second after letting off. I know wiring for starter etc is fine as it was running before.

 

I'll check the jet sizes tomorrow.

[Longboarder]

Starting just after you release the starter

I should have said 'seeming to try to start/coming close to starting'. Try the test I suggested. Nothing to loose and it takes a minute.

 

Nigel

[theduck]

Sorry I just spotted a typo in my original post, the engine will fire while cranking, let off and it dies. Though that's one or twice out of many attempts today.

 

I'm going check floats and clean jets and while I am at it check the sizes in the morning.

[theduck]

Checked carbs over today and jets etc as below.

 

Idle jets - 50 / 7850.1

 

Emulsion tubes

right bank of each carb 7772.5

Left bank of each carb 7772.1

 

Main jets 115

 

Pump jets 40

 

Although odd, I figured it should start in those idle jets and the emulsion tubes although mismatched shouldn't come into it. So reassembled and tried gain with tweaks to ignition timing. Very crudely set the ignition to 10degrees advance, which it wasn't far off anyway and still no joy.

 

Checked spark and all good. Plugs were black and some wet, though I put that down to how much I had been cranking it over without firing. The blackness from too much fuel through th 50idle jets.

 

Before I order bits, I assume 40 idle jets and replace emulsion tubes so they are all .5s should be ok?

 

 

 

[Guest Ian & Carole]

Checked carbs over today and jets etc as below.

 

Idle jets - 50 / 7850.1

 

Emulsion tubes

right bank of each carb 7772.5

Left bank of each carb 7772.1

 

Main jets 115

 

Pump jets 40

 

Although odd, I figured it should start in those idle jets and the emulsion tubes although mismatched shouldn't come into it. So reassembled and tried gain with tweaks to ignition timing. Very crudely set the ignition to 10degrees advance, which it wasn't far off anyway and still no joy.

 

Checked spark and all good. Plugs were black and some wet, though I put that down to how much I had been cranking it over without firing. The blackness from too much fuel through th 50idle jets.

 

Before I order bits, I assume 40 idle jets and replace emulsion tubes so they are all .5s should be ok?

 

Well that explains why the linkage didn't match/fit they are not a matched pair.

 

[theduck]

How do you get they are not a matched pair from that? Both carbs were jetted identically...

 

The emulsion tubes were different within the same carbs. So one carb, left bank 7772.5, same carb right bank 7772.1. Same for BOTH carbs.

 

The reason the linkage didn't fit was because the spacing on the pinto manifold is different to the spacing on the XE manifold they came off.

 

Back in topic, are the idle jets too big to get the car running? Will my suggested purchases be ok to run the car on?

 

Thanks

[Guest zerorace]

did they run ok on the xe if so not the carbs, could be a air leek or split 'O' ring

what fuel pump are you running are you sure it is not flooding by over pressuring the floats

the list is endless if they run on the xe

[richardm6994]

sounds like ignition timing to me! You sould be able to bolt the twin 40's onto the engine and it runs (albeit not great as carbs will need setting up)

 

1 person in the driver's seat cranking the engine overand a bit of throttle and another person adjusting the dizzy position until it fires!

[theduck]

I'm running the mechanical pinto pump. I believe they ran on the XE, but then I bought them online so who knows if they actually did? Setup on them as detailed above certainly seemed odd.

 

I've got some new idle jets as I wasn't happy with the 50s as they are much too big for the engine and got some genuine new ones for much cheapness so will fit these anyway.

 

I've tinkered with ignition timing and got no improvement, and it can't have even too far out as it ran on the previous carb and nothing else had been changed other than the carbs.

 

Air leak I will investigate as its a possibility I hadn't considered.

[maccavvy]

do you have a pressure regulator ??

[theduck]

No, just straight off the mechanical pump which I have read should be fine?

[MarkBzero]

how long does it run for before cutting out? Does it only run when held against the ignition (starter engaged, normally position 3)?