| Author |  Topic  |
andydeans3
V4 Guru
United Kingdom
2016 Posts |  Posted - 27 Dec 2020 : 18:37:43  
| Gavin.
Blew the fuel line from rear to front today.
Clean as a whistle, so this only leaves the the NRV (Check valve) close to the tank,the pick up pipe in the tank, that I can't see, or something to do with the operation of the fuel pump.
Perhaps as Derek suggested, the fuel pump operating rod is too short and is not operating the pump properly. However if that was the case why only this very, very, intermittent problem?
I think I'll try the electric fuel pump for a few weeks, and see what comes.
Thanks to all that have contributed.
1978 LHD SAAB 96
1978 MGB Roadster
2008 LHD "Classic" Renault Twingo
1991 Nissan Figaro |
Edited by - andydeans3 on 17 Jan 2021 05:16:58 |  |
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UK_Sub
V4 Guru
United Kingdom
2558 Posts | Posted - 28 Dec 2020 : 10:54:16
| This may not be relevant to your situation, but when I was having trouble with my fuel pump, I took it to the Saab Doctor in London and tried a couple of (used) pumps, that either didn’t work or worked as well as my original one,
I was told it might be a worn camshaft, so fitted an electronic fuel pump, which worked perfectly, once I’d moved it to under the back seat (it was originally in the engine bay and would cut out when it got too hot in traffic) | |
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Dynorog
V4 Fanatic
United Kingdom
250 Posts | Posted - 28 Dec 2020 : 11:24:27
| When people have fitted an electric fuel pump what sort/make of safety cut out do they use?
Cheers
Dynorog | |
|
Derek
V4 Guru
United Kingdom
2191 Posts | Posted - 28 Dec 2020 : 14:01:43
| | Why have you got a check valve near the tank? Mechanical pumps have their own check valve. There was a small trend for fitting marine type check valves between the pump and the carb a while ago. They aren't necessary and can be more of a hinderance than a help. | |
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andydeans3
V4 Guru
United Kingdom
2016 Posts | Posted - 28 Dec 2020 : 17:33:01
| Derek
When I spoke to Steve Broadhead back around 2017, when this problem first appeared, he suggested fitting an NRV under the back seat. WHen I did, the problem vanished, until September this year.
I was going to remove it, as part of this current trouble shooting exercise, just to eliminate it.
I've had a small NRV between the pump, and the carb since I first got the car. Stop the fuel draining back, when you stop the engine.
1978 LHD SAAB 96
1978 MGB Roadster
2008 LHD "Classic" Renault Twingo
1991 Nissan Figaro |
Edited by - andydeans3 on 28 Dec 2020 17:35:08 | |
|
Iain G
V4 Fan
United Kingdom
159 Posts | |
Iain G
V4 Fan
United Kingdom
159 Posts | Posted - 28 Dec 2020 : 20:41:08
| I should add that I only use Huco’s on the Sonett because fuel flow was very poor and on the 96 because it has twin 45 dcoes and I wanted to make sure of constant pressure regardless of revs.
In theory a good mechanical pump and drive should be fine - I know Paul Darlington ran twin 48 dcoes on the standard system.
Hucos very easy to fit and have been very reliable in my experience.
Iain G | |
|
Iain G
V4 Fan
United Kingdom
159 Posts | |
Dynorog
V4 Fanatic
United Kingdom
250 Posts | Posted - 29 Dec 2020 : 07:57:29
| Thanks for the cut out switch info Iain
Cheers
Dynorog | |
|
Iain G
V4 Fan
United Kingdom
159 Posts | Posted - 29 Dec 2020 : 12:55:09
| You might some other eBay listings for switches including the male connector for the wiring.
Iain G | |
|
melle
V4 Guru
United Kingdom
3833 Posts | Posted - 29 Dec 2020 : 13:28:42
| I use a standard Ford inertia switch and a Saab 900 fuel pump relay in my 96, see my 96 project thread.
www.saabv4.com | |
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andydeans3
V4 Guru
United Kingdom
2016 Posts | Posted - 29 Dec 2020 : 19:45:50
| Melle
Hey, Merry Christmas.
Can you send me a link to your 96 project. Can't find it.
My MGB has an electric fuel pump, but doesn't have any sort of safety cut out.....Is this a safety cut out, in case of an accident, or fuel leak?
1978 LHD SAAB 96
1978 MGB Roadster
2008 LHD "Classic" Renault Twingo
1991 Nissan Figaro | |
|
christophe
V4 Fanatic
France
227 Posts | Posted - 29 Dec 2020 : 21:07:05
| | In case of an shock like an accident, the inertia switch cuts the electrical supply to the pump. Thus, you won't be spilling your fuel everywhere to worsen an already difficult situation. | |
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andydeans3
V4 Guru
United Kingdom
2016 Posts | Posted - 29 Dec 2020 : 22:15:12
| Thanks Christophe.
What I suspected.
I wonder why the MGB doesn't have this fitted....ahem, I think I know why....
1978 LHD SAAB 96
1978 MGB Roadster
2008 LHD "Classic" Renault Twingo
1991 Nissan Figaro | |
|
melle
V4 Guru
United Kingdom
3833 Posts | Posted - 30 Dec 2020 : 09:58:53
| @Andy: http://www.saab-v4.co.uk/speedball/topic.asp?topic_id=31068&whichpage=5 Scroll down a bit for the fuel pump (I've used a Facet 40105)/ inertia switch (Ford, Jaguar and other Ford based cars all use the same type or one like Iain linked) and the next page for the relay that was added later. Saabits sell OEM 900 fuel pump relays (p/n 9550948) for less than 25 quid; their website only lists an aftermarket one that is more expensive, so send them an email/ give them a call.
www.saabv4.com | |
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| Topic | |
Oil Pressure Light
