Electric fuel pump wiring (Novice alert!)

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Merrsh1
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Re: Electric fuel pump wiring (Novice alert!)

Post by Merrsh1 »

SeanMc1970b wrote:Trouble starting the van with the electric pump on.

Unplugged and poured a thimble of petrol in the carb and it starts okay. Even when I reattach the power to the pump it cuts out, its like the engine is getting too much fuel.

Any thoughts guys, off a few days next week and was hoping to move it to do a bit of welding.

Sean
I’ve now got similar, van takes a while to start and higher idle... I’m going to reduce the idle speed tomorrow and see if that does it. It seems like mine now gets too much fuel as well...

I’m wary of altering the mixture though...


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SeanMc1970b
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Re: Electric fuel pump wiring (Novice alert!)

Post by SeanMc1970b »

But is now starting when the + is taken from the battery and not the coil?

E D I T: and now I think I fudged the relay......thats enough bodging for one day :?
1983 1.9 dg

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Re: Electric fuel pump wiring (Novice alert!)

Post by Merrsh1 »

SeanMc1970b wrote:
But is now starting when the + is taken from the battery and not the coil?

E D I T: and now I think I fudged the relay......thats enough bodging for one day :?
I know when I did mine I read that there can be a voltage drop from the coil and you may have to take power from the alternator.


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SeanMc1970b
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Re: Electric fuel pump wiring (Novice alert!)

Post by SeanMc1970b »

Merrsh1 wrote: 10 Apr 2021, 17:52
SeanMc1970b wrote:
But is now starting when the + is taken from the battery and not the coil?

E D I T: and now I think I fudged the relay......thats enough bodging for one day :?
I know when I did mine I read that there can be a voltage drop from the coil and you may have to take power from the alternator.


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Thanks will try that in the week
 
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Re: Electric fuel pump wiring (Novice alert!)

Post by Epiphone »

Hi,
just got my MOT and drove it 2.5hrs back home and then a few hours later (wanted to drive to italy) it wouldnt start, realised I was missing the electrical whirring noise. I also thought it was a gremlin from from doing a "big" drive, so decided to take car and tent  :(

Then a few weeks went by and all is fine, went on 1 or 2 small trips - 10 mins driving

This week, went on another 10 min drive to the scrapyard (oh the irony!) and it wouldnt start up, missing the electrical whirring noise.
Got towed home by the Mrs, oh the shame!

Checking now, and the electrical whirring noise is back, and I noticed its 2 fold, there is the Fuel pump noise and (when I disconnect the fuel pump) (from what im ready in Haynes) the Fuel pump relay electrical whirring noise coming from the engine bay too, is that right?

I can also see the voltage on the pump too when turning the key. I tested the relays recently and they seemed to open and close on demand etc. What else to check - the typical grounds?

Both Relays have the constant live (30) and also there is a ignition live coming on the (86)

now I have an issue with finding the fault when its working  :roll:

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Re: Electric fuel pump wiring (Novice alert!)

Post by Epiphone »

hmm, I did have issues at the starter recently too! Would result in nothing happening when turning the key, corroded connection here, will check again
 ImagePosted: Tue Feb 15, 2011 11:29 pm    Post subject:Image

I had a similar problem after installing my new engine. It was a loose connection at the starter, under the rubber boot. Resulted in insufficient voltage to the fuel pump as well as to the distribution box in the engine compartment.

Check your grounds too, including the transmission ground strap, engine ground strap.
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Epiphone
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Re: Electric fuel pump wiring (Novice alert!)

Post by Epiphone »

still not reproduced the fault, but I thought I would replace my Fuel Pump and filter anyway.

But new pump is very loud, making a gurgling sound occasionally (when the engine is running) does it take a while for the filter fill up and for it to run smoothly etc?

When I disconnected the pipe from the tank to fuel pump, it didnt pure out uncontrollably, in fact only did a small stream when I lowered the pipe otherwise when holding the pipe up, nothing came out.... is that normal?

I also installed a new pump bracket and rubbers and I double checked the fitting, seems fine

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Re: Electric fuel pump wiring (Novice alert!)

Post by multisi »

Is the pump the expensive Bosch type or a cheaper alternative ?  The cheap ones tend to be noisy.
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Re: Electric fuel pump wiring (Novice alert!)

Post by Epiphone »

yes it is a cheaper one, I see now, 50euros compared to over 100 for the Bosch one

but should it continue to make noise when the engine is running, as the fuel under pressure is flowing through it, but not pumping itself, right?

and I just figured out that its the idle speed control valve, which is making the noise in the engine bay at the same time as the pump is priming

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Re: Electric fuel pump wiring (Novice alert!)

Post by multisi »

The cheap ones seem to make buzzing  noises all the time, Brickwerks dont stock them any more .
1992 red lle 2.2 subaru 1990 rhd caravelle 2.2 subaru 1986 california import vanagon

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Re: Electric fuel pump wiring (Novice alert!)

Post by Epiphone »

and with the engine running there should be voltage across the pump?

otherwise, all seems fine and working, just want to understand how the pump should run

is that why the Fuel Pump relay (53) has the direct (with resistor) connection for the 85/86, to supply the fuel pump with a constant low voltage but then the ignition switch supplying the higher voltage at start/prime time?

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Re: Electric fuel pump wiring (Novice alert!)

Post by Epiphone »

hmm I think after more research that the ECU is controlling all of this and that as long as the pump only primes for the 3 seconds (and not longer) at ignition, then this is fine

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Re: Electric fuel pump wiring (Novice alert!)

Post by Epiphone »

happened again, over 1 year later, :( weather is hot today, like it was back then 

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Re: Electric fuel pump wiring (Novice alert!)

Post by Epiphone »

so I figured out that the coil had no power and after following this thread viewtopic.php?t=164733

I just bridged the cable from the engine bay junction box (black cable and yellow connector) to the Black coming out of the ignition), it seems this is broken.

now both the fuel pump and idle stabiliser, and I guess the crankcase breather heater all come on 

now the coil has spark when I ground the middle of the Hallsender connector

still doesnt start tho at the moment, is it flooded now after 2 days of bridging the fuel pump relais etc?
 

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