bajachris88 wrote:i rekon having that tachometer based switch or charge light off the alternator is the way to go,
but have an override momentary push button that you hold while cranking to 'prime' then of course the alternator or tacho goes and u let go of the override then technically it should run itself :P
An on/off switch thru the ignition is better...
I always switch the pump switch off automatically after turning the key off.
A light comes on when the pump is turned OFF....
and ignition is ON....
LEE
- Helping keep Air Cooled VWs on the road - location: SCONE in the Upper Hunter Valley - Northern NSW 320 kms NNW of SYDNEY---
Joel wrote:That's all well and good on a fresh engine but one that's got a few miles under it's belt can take a few seconds to get oil pressure and when hot the oil light can flicker at idle which can upset the relay or worse yet cut the fuel pump out.
not fun when you're sitting at traffic lights.
It's so easy to get a tachometric fuel pump relay, nearly all fuel injected cars use them.
I had one from a Commodore and it was great, it primed the pump for 2 secs when you turned the ignition on then waited for a tacho signal before it ran again and stopped soon as the tach signal stopped.
Hi Joel, if I had a motor that when hot, the oil light would flicker, I would pull it down & freshen it up before it shit the tin. Your tachometric fuel pump rely from a dunnydore sounds like a good set up, cheers Frank
I'd do the same as well but you would be amazed how many of the general public don't.
I used to see it all time at the garage when VWs were alot more common as dailys, they would come in for a pink slip or a service, usually a few thousand miles overdue for an oil change and the light would just flicker at idle if it was still hot.
My best mates 68 does also does it.
It's running perfectly, has good compression etc but it's done nearly 200,000 miles since we put that motor in back in '96 and when hot gets the light flicker.
He's getting a new engine eventually so is happy enough to leave it.
Craig Torrens6 times Australian, 7 times State Hillclimb Class Champion
About to install my Ea81 into the trike (see non Vw conversions). So a fuel pump is needed. It is great you guys on here answering these questions especially the safety aspect eg cut outs.
Well done guys. you are serving more than the OP most of the time.
I had a tachometric relay from a EFI BMWon my sons 1303 but it didn't like the signal coming from the MSD, the tacho signal comes out of the MSD box and not directly from the coil -
So I've now fitted a double through relay.
87 not used
87A goes to the pump
85 goes to the oil pressure warning light wire
86 & 30 are joined and fed by the ignition switch
On this relay when its at rest with no ignition feed, no power comes out of the relay at 87 or 87A
Turn the ignition on and the relay gets earth from the oil pressure switch, no power comes out of 87A, it only come out of 87 which is not used.
When the oil pressure builds the warning light goes out and the relay has no earth so it goes back to rest state but power goes through the relay at pin 30 and on to 87A to power the pump, if there is no oil pressure the relay is earthed again which takes power away from 87A.
The BMW tachometric relay cost me about $80 or $90, the Hella double through relay was under $20
The things that are not ideal with this setup,
1. no fuel flow until oil pressure builds, not ideal if the carbs are dry for some reason.
2. pumps stays on until the pressure drops when the motor is cold as the oil is still gluggy
ok , so the unit contains a metal ball (conductor) that sits in a steel cone/ inverted pyramid that makes a circuit. Once there is impact/force it throws the ball out and cuts the circuit to the fuel pump. It also has a reset knob if it does jump out. Would take a good hit to knock the ball out though and one that I hope never to get 😁
thanks for that tip binner. i just ordered one of the collision shut-off switches, I thought it was a no brainer.
As well I got a Peel CP30 fuel control (tachiometric) relay. $40. They are used by the auto-gas installers and do everything that is needed for a petrol fuel pump. Monitors tacho signal, puts out a brief prime signal when ignition first on, and switches off if tacho signal lost. Might have to use it to drive a standard relay to switch pump supply if the contact ratings arent rated high enough for the pump amps.
Further to the above, new engine is in car and running. The Carter rotary pump is a very loud fecker. No vibration as it is rubber mounter but can hear the whirring on idle. Good thing the new engine and exhuast drown out the noise 👍
Have had absolutely no issue at all with the Rabbit Relay set up.
ok,so Im' now up and running but because I have never had a vw with an electric fuel pump I'm not sure if i have the regulator set correctly, after about 10mins of nice idle it sounds like the carbs starve of fuel and the engine dies... could this be fuel starve, wrong psi/flow for reg?
I bought a reg off CIP1 but it doesn't have a bypass back to the fuel tank and now I'm thinking maybe it would be smart to run a reg with a return to the tank. What do you think of these (link below) and would 3psi be too much for my donk, I'm running dual 40 idfs with jet doctors and a empi HD fuel punp at the moment. Or does anyone have a choice of regs to use .........
Also, would it be smart to make the fuel hose length the same from both carbs to meet the fuel line, at the moment one is shorter than the other?
If your going to go electric, buy a Pierberg pump. They are 3psi, suck and pump as well. The only thing is they are $150 but you get what you pay for. Excellent quality and hassle free. I ran one for 6 years in my bus and it never skipped a beat.
I bought one of those Peel CP30 LPG relays off Ebay to fit up with my new fuel carter rotary pump. Tested out the prime function which it does have thankfully. That makes the install very straight forward. Weird thing with the webers is they empty the bowls if sitting for longer than a week. Hence the electric pump. The kaddies never did that at all. One pump on the throttle and it was started.
Just have to machine up some adapters from the 5mm fuel tank pipe to the 8mm pump fittings.
It will all be OK in the end, if it's not OK it's not the end!
68AutoBugBeetle Restorer - Experience over 138\% - YIKES --
I have a plastic electric fuel pump which is located under the fuel tank and I have an ON/OFF switch under the dash and a bright light on the dash to show it is OFF.. The pump is rubber mounted but I can hear it ticking... when it is switched ON... Car will drive about 100 meters until the bowl is dry...
I also run a Holley fuel pressure regulator with a small gauge attached to it.. on the LHS of the fan housing..
I have run these for over 10 years. I always carry a spare identical electric fuel pump for just in case..
3 PSI with a brasillian WEBER dfv-228 carburetor 1600 SP engine.
LEE
- Helping keep Air Cooled VWs on the road - location: SCONE in the Upper Hunter Valley - Northern NSW 320 kms NNW of SYDNEY---
My understanding is that the tachometric relay is mainly a safety measure. The kind of scenario where you have crashed or rolled the vehicle and engine has stalled and you do not have the presence of mind, or indeed the consciousness, to turn off ignition or any other switch. The Peel relays are so cheap and easy to install it just makes sense IMHO.
