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Where to buy fuel pressure gauge for CIS fault finding?

NeilH

PCGB Member
Member
Hi all

I have a cold start problem on 3.0 CIS.
The longer the car sits idle - greater than 2-3 weeks - the more cranks it needs to fire.
If left just for a couple of days cold it's OK

I suspect residual pressure drops off over long period. Am looking to source pressure gauge and valves to fit to diagnose.

Anyone recommend anything that's currently available in the UK? Can see lots of pelican parts post to a K-jetronic kit that seems discontinued. Anyone used anything currently on the likes of amazon?

Thanks for any help.

Best regards
Neil

 
Isn't it an electric fuel pump? I don't think it relies on cranking the engine to prime the system.
What starting procedure are you using?
For me, I turn the engine for about 3 seconds with half-throttle then stop. I take my foot off and then depress the pedal a bit and then re-crank and it usually fires up within a second or so.
The diaphragm plate thingy in the airflow system has contacts that operate the electric fuel pump as well as the ignition circuit which is why I press the throttle, but don't really know if this has anything to do with how quickly it fires up.
Hope this helps.

 
Hi old and Slow

Yes you're right - CIS pump starts only on the diaphragm lifting - while cranking or running.

You may have a point! I've only owned the car a few months and sure the previous owner said "no throttle while cranking". But can see with what you now suggest - the open throttle will ensure the low cranking pressure will fully hit the diaphragm to ensure a decent lift of it and the microswitch being operated throughout.

I'll give it a try.

Only thing is it starts ok when been idle a few days but seems to be an issue after a week and progressively worse the longer it's left idle. There's forum suggestions of the accumulator or fuel pump check valve slowly releasing residual fuel pressure back into to the tank. If so, the Pump has to run longer to get pressure back up the next time you crank it after so long.

Regards
Neil



 
Fired SC up for first time in 4-5 weeks.

Used half open, and almost full throttle, when cranking. Took about 5 goes before signs of firing - then suddenly starts.

This was a little quicker than trying with closed throttle. Am sure this means I slowly lose system pressure over this time though and will need a gauge to prove the cause.

Understand another test is to turn ignition on, take air filter out and lift air flow plate upwards - should hear pump run and a distinctive sound just at the point the injectors get enough pressure and start spraying.

Thanks
Neil

 
hi. My 911sc passenger electric window has decided not work. I have checked the motor and it works and changed the switch but still wont work. Has anybody got any advice?
 

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