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Discussion Starter #1
I just pulled the in tank fuel pump on my 83 Spider and noticed some sort of wound copper wire coil that goes from the positive on the pump to the positive on the cover. It had a shrink wrap tube to seal it which has deteriorated. I am wondering if it should be replaced, and if so with what?

Thanks for your help!!!

Dan
 

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Discussion Starter #3
going to the moon...

Thanks Eric, It is reassuring to know I won't be going to the Moon anytime soon...


Looks like the in tank fuel pump is bad, how long does it take to damage the inline pump, as I was driving most of last summer without realizing the in tank fuel pump was bad. Problem I was having is exactly what I see in posts regarding trying to run the car with the inline pump only. It would seem to be running out of gas with the tank half full. I had the problem a number of times, and was thinking it was a vapor lock... I see it can cause the inline pump to overheat, what's the easiest way to test for damage?

Dan
 

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I'm not sure what you mean by 'how long does it take to damage the inline pump?' If the car would run OK with more than 1/2 tank then the inline pump (aka main or high pressure pump) is likely fine. It is designed to push fuel at high pressure but it does not suck well. Thus the in-tank pump provides a constant supply of fuel to the main pump (at low pressure but adequate volumes).

What can ruin either pump in short order (probably measured in minutes) is to run them with no fuel. The fuel lubricates & cools the pump. So don't remove the pump and hook up 12V to 'test' them.
 

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Discussion Starter #5
fuel pump

Thanks Eric, I'll be careful when testing. I replaced the inline pump about a year ago, and it didn't last very long. I do have a sock filter on the bottom, and it was clean when I pulled it out. Would I be better off buying one from International Auto than my local Checkers? Also, if I have to replace the main pump, would Bosch be the best replacement?

Dan
 

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I can't really say who might have the better part. Two advantages of buying from an Alfa parts supplier are 1) perhaps a better chance of getting a part that really fits vs a part that can be made to work & B) supporting an Alfa parts supplier might help keep them in business.

One thing to consider when working with our old cars is the age of the wiring & connectors. When they were new the wires/connectors/etc were plenty adequate for the designed electrical loads. After many years a bit of corrosion, looseness, arcing, age, etc hampers how well the electrons can flow. This reduces the efficiency of the electrical item and that can shorten their life. It is a good idea to clean all electrical connections, make sure crimps are tight, insulation is intact, wire strands are not broken, etc. If you are willing to learn an easy but useful skill try Googling 'voltage drop test'. Here's some info my brother wrote about Voltage Drop Testing (but first you have to answer the prerequisite question...)
 

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Discussion Starter #7
replacement parts

I have successfully passed the test...

Lots of great info for the man of the house!
 

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DanT, if you replace the main pump a year ago and it is bad again, you might want to look at your fuel tank for rust...I had the same problem, but after about 7 months I had to replace both fuel pumps all filters and the fuel tank, which was seriously rusted....
 

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FYI,
I've used an Autozone main pump ($159) for almost 4 years after a series of Bosch pumps. Very quiet and no issues. Your mileage may vary.

I've seen Advance Auto pumps for roughly the same price but AA always has lots of coupons available (google and see!). Last time I looked, I think you could get a pump from Advance for ~100 plus tax. I have no experience with the part.
 

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I can't really say who might have the better part. Two advantages of buying from an Alfa parts supplier are 1) perhaps a better chance of getting a part that really fits vs a part that can be made to work & B) supporting an Alfa parts supplier might help keep them in business.

One thing to consider when working with our old cars is the age of the wiring & connectors. When they were new the wires/connectors/etc were plenty adequate for the designed electrical loads. After many years a bit of corrosion, looseness, arcing, age, etc hampers how well the electrons can flow. This reduces the efficiency of the electrical item and that can shorten their life. It is a good idea to clean all electrical connections, make sure crimps are tight, insulation is intact, wire strands are not broken, etc. If you are willing to learn an easy but useful skill try Googling 'voltage drop test'. Here's some info my brother wrote about Voltage Drop Testing (but first you have to answer the prerequisite question...)

Great site! I have a son that turned 16 last November. We put a used motor in a used Jeep.
He is very happy!
 

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Discussion Starter #11
Thanks for your advice. I replaced the fuel filter when I put in the new inline pump, and haven't checked that yet. The sock on the in tank pump was clean, no evidence of rust or debris.

Dan
 

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Hilarious link - I don't feel so alone anymore in my struggle for "garage time". I've seen in-line fuel pump eBay listings for $50 w/ free shipping. I might give one of those a try as soon as I discover mine's bad. I suspect it is, the tank and in-tank pump were a corroded mess. I'll check the in-line as soon as I can find the "garage time".
 

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What fuel pressure and fuel flow should the in line pump and in tank pump have ? Also. Have an '84 Sipder. Last summer ( hot day ) While going UP mountain passes car would sort of vapor lock. Never cut out but had to down shift and rev engine. On down side O.K. and on flat O.K. Didn't matter fuel tank full, 1/2, or near empty. In tank pump seems to be putting out sufficent flow, installed in tank sock filter (didn't have one) Replaced 1 1/2 year old in line filter, pained underside of gas tank silver. Haven't tested yet - too cool.
Any thoughts ? Thank You Jim Co.
 

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Not sure what the pressure should be, but the intank pump(at least in my 91) does not really have a lot of pressure, just enough to feed the main pump...also I thought the intank pump was added to stop the vapor lock that was occuring in earlier models.....
 

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In tank boost pumps should put about 3-3.5 psi to feed the main supply pump. You may "deadhead" test the in tank boost pump. Very easy to do.
 

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...also I thought the intank pump was added to stop the vapor lock that was occuring in earlier models.....
The intank pump was added to cure driveability issues (read fuel starvation) with low fuel tank levels after Alfa switched to top discharge fuel tanks in 1977.
 

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In tank pump

I rewired the main pump from the battery because it wasn't getting power, and now the car runs, seemingly fine.
My concern is that by bypassing the system to get the main pump power, the in tank pump my not have power now.
1. Do the two get power from the same fuse/location?

2. Does the in tank pump only function when the car is on, or when the starter is turning?

3. I was wondering how you know if in tank pump is functioning.

4. Is it ever necessary to replace the in tank fuel sock filter or clean it?

Thanks,
Rich

1988 Graduate/Spider
I found this response from Papajam, but I don't really understand the locations he is referring to.
The single fuel pump relay powers both fuel pumps in the L-jet system as well. A single red/white wire from the relay output goes up the right side of the car, through the firewall and connects to the inertia switch. From the switch, the wire goes across the width of the firewall where it then re-enters the cabin and goes to pin 9 of connector G73, located behind the fusebox, where the wire splits into two red/white wires; one going to the in-tank pump and the other to the main pump.
 

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1) In tank pump functions at the same time the main pump does: when the drive relay activates or whn the start circut bypass is activated.

2) Listen closely with the eninge running and you should be able to hear it humming with your head in thr trunk. It's a higher pitch than the main pump.
A length of vacuum hose used as a stethescope may help if you can't desicern it without an aid.

3) Yes if there's any contamination (rust, sand, junk) in the tank. It will degrade over time regardless and thus need replacement.

Wiring the main pump to the battery would be a bad plan from a safety aspect.
Without the drive relay, the pump can continue to run after the engine has stopped running in an accident, and should one of the fuel lines have been ruptured in said accident, well....

Main pump and in~tank pump are wired in parallel with each other. What normally makes one operate also normally makes the other operate.
Should there be a failure as a result of the drive relay, neither pump would run unless the engine is being cranked (start bypass circut runs them then)
Putting the main pump on the battery and doing nothing for the in~tank pump can easily result in the in~tank not operating depending on how the main pump was rigged.
You won't know if its an issue or not until you get well eblow half a tank of fuel as that's about the point at which the main pump can't siphone fuel so starts to starve the engine.
The whole purpose of the in~tank is to allow the main pump to work the way its supposed to: supplying high pressure and high volume to the rail. w/o the in~tank, the main has to struggle to do its job.
 

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pump

1. If i were to pull out the in tank pump, do you need to empty the gas tank first? Is gasoline going to drip everywhere?

2. Is there an easy way to know if the in tank filter is clogged. The car has 56000 miles. 1988 spider. Do people clean it or just replace it? and is it a mess to do?


The car doesn't have a roll bar, so I figure if I get into a crash, Ill have more to worry about than the gasoline still running...




Thanks,
Rich
 

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Tank need not be empty to remove the in~tank pump.
It's attached to the sending unit and pulls out of the top of the tank with it.

Can't know anything about the filter without seeing it.
Can't see it without pulling the sending unit.

A rollbar won't prevent entrapment, nor will you likely ever actually roll the car truth be told, but trapped, fully concious and otherwise uninjured so you and/or a passenger can get the full enjoyment of being roasted alive isn't on the top 10 list of best ways to go I promise you.

Its such a little thing to do right with so much potential positive benifit.
Why risk a horrific outcome by doing it wrong because it was a little easier to accomplish?
 
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