[510rcr]

Help my daily driver is down............

After 5000 miles a new IAP in tank pump failed which was put in by someone else. I replaced it and when I pulled it out I felt the power line (in tank section) and it was mushy. New to a spider, I thought it may be a burnt fusable link and opened it up and ruined whatever it was (coiled little wire?). I replaced it with a standard wire and new AIRTEX brand aftermarket pump which worked for less than a tank .

1. Did I remove some sort of aparatus to lower voltage?
2. I could not find anything that says what voltage the pump is to run on.
3. If it is necessary (coiled little wire assy), can I replace the wire assy with something else when I buy my next pump? I do not see that it is a purchasable part anywhere. Maybe something from Radio shack?

I have an IAP service manual but I $#@? at reading wiring diagrams.

Thanks in advance!

Matt A. & clan of misfits:

- Rusty, '83 Spider
- Rodney, '88 BMW 325is (RIP, big crash), organ donor card signed so transferring everything into a...to be improved 89 E30 roller.
- Red, '92 Dodge diesel 4WD (tow vehicle & very uncool backup daily driver)
- Tapanga, wife's Civic and only vehicle which does not eat my time.
- (needs no name) '71 Datsun 510 race car which I can't afford to race anymore (It is my first true love - as evidenced by shirt my wife gave me which has its picture & states so).
- Tool, '88 Toyota 4WD - $50 rolled, beat, abused but runs & pushes winter snow, plus seconds as a poor man's Gator & river toy, plus a complete embarrasment to my wife.
- Assorted array of parts cars to keep the misfits running.
JUSTIFICATION: Tags, taxes & ins on all my misfits less than the Civic!!!!

 

[Tifosi]

'Mushy' coil like thing?

Somehow I'm of a mind you damaged the fuel gauge sending unit, not the pump.

All I ever recall in there was the filter sock, the pump, the rubber connector hose that feed form the pump to the output line and two wires to connect the pump.

Everything else, including the other wires, is for the gauge sending unit.


In general the pump should get a steady 12V to work and have a very good clean ground outside the tank.

The sender puts out a variable signal, but also has a 12V feed.

Are you absatively posilutely sure you connected the correct wires to the correct blades on the outside of the tank?

Does the main pump (under the right side) function as it should, or is it wonky too?

If it works, then the issue is likely at the in-tank pump or wiring.

If it doesn't there may be a problem with the tachimetric relay under the cargo panel, or it's wiring, or it's fuse.


Please to click the link in my signature block to find more extensive information regarding the L-jetronic system.

 

[510rcr]

In tank 12v line

The line in the tank was definitely the 12v power feed as it went from the left side of the pump to the bottom side of the pink 12v feed. The in tank section, when unplugged, was a fine wire slightly smaller in diameter than a
.025 pencil lead and it streched out to about 10" long. It was coiled and inside a loose wire covering. I tried to attach a picture of the wire that came out.

Nice site you referred, I will print it out for sure.

Matt

 

[Elio Comello]

What you have here IMHO is a "rube goldberg" attempt to make wiring from the spade connector to the lug connector. Rube coiled up excess wire, which looks too thin and covered it with some plastic polymer sleeve which is not resistant to gasoline.

Something is strange that makes your in tank pumps "fail". Could you have a problem with the discharge line (restricted/plugged?).

BTW, I'm pleased to see you are listening to your partner and putting the toilet seat cover down...LOL.

I would suggest that you renew the spade connector to lug wiring to the proper guage and correct length so as not to need to coil up excess. It looks like you have too much wire, several connections and what appears to be small guage telephone wire, doubled up to carry the pump current.

Be careful with sparks and gasoline fumes!!!!

Best regards, Elio

 

[144]

Good Lord. It looks to me that you're lucky that your gas tank didn't turn into a bomb and you weren't gravely maimed.

Whoever did that was a (insert explicative of your choice) moron.

That's a poster child for why you need to carefully, and in great detail, inspect any old Alfa that you buy, especially one that the owner doesn't appear to have maintained the car in anything less than excellent condition.

 

[papajam]

You might want to give this thread a read. Although the jury is still out on exactly what it is, this makes two Spiders with the same device. Now unless both of these Spiders were owned by the same PO, I'd say it's factory.

 

[144]

Whatever it is, it doesn't look safe. Almost looks like splice coverings on the wire. If anyone has an in-tank boost pump and hasn't inspected it, I recommend that they do so.

 

[papajam]

Just did a bit of research and although I didn't find out what the device is, I did find the attached recall completed sticker. The black arrow is pointing to what appears to be the device. The blue arrow is the spade connector and the red arrow points to the ring terminal at the fuelpump. So it would seem that the device is indeed a factory item.

Without knowing what the device is, it's difficult to determine what the device does. However, I'll hazard a guess that it's to reduce EMI.

 

[Tifosi]

I'm confused a bit more than normal righ this moment:

Reduce EMI from what or where? (pump eminations, or general wiring/harness static?)

I understand the concept in a sort of limited way, but that doomahickey is buried in the tank and about 4 metal walls and 3 feet away from the ECU.

My weak mind would imagine that if it had to have something in that circut it would be simpler outside the tank rather than in it. (and along the same train of broken thought: I'm mildly curious why there isn't/wouldn't be one on the much closer to the eCU and far less shielded main pump)


Or is it another case of engineers making it look good on paper, but in reality it's more useless and troublesome than it's worth?

 

[Elio Comello]

Tifosi, if the operation of the pump caused "ripple" noise on the DC bus, it would effect the whole car and it's electronics. It is not for radiated electrical emergy RFI or EMI.

I believe the purpose of the "Choke" (name for the parasitic wound electrical suppressor) may have been to supress back emf which could be generated for short bursts, when the fuel in the tank got low and the in tank pump was "gulping" ie., grabbing quick gulps of vapour/air. The pump, suddenly loosing fluid, could with its rotor inertia, speed up, becoming for short bursts a generator. The "choke" may have been added to soak up the energy spike. (A theory anyway).

The link you referred to Papa, is very intersting, but the wire in question in this thread looks like a "retrofit". The wire is much longer and not the gauge of the original (much thinner).

So what was the Alfa Recommendation that went along with the picture (Recall) Jim?


Best regards Elio

 

[papajam]

Well, looks like I guessed wrong that the thing reduces EMI. I'll buy into the choke explaination though.

Elio,
The wire pictured above is that of the device after it's been unwound. I believe it to be the same device as pictured in the posted link above.
The recall was to retrofit intank fuelpumps into 77-79 Spiders.

 

[Tifosi]

So it would work in principle at least as resistor type spark plug or sparkplug wires to try and alleviate the pulses then.

I still don't quite understand how the main pump wouldn't have something simular also, as when the in tank gulps air, a %-age gets shot down to the hardline and making a pulse again in the main pump, unless it's less suseptable due to it maintaining a slightly more constant/steady pressure and flow rate in general.

Look ma, I'ma larnin

 

[510rcr]

Papajam ID'd it

Papajam's link shows exactly what mine was, there were mini coils that same size although I do not think it was actually wound around anything unless its at the bottom of the tank somewhere. I replaced the pictured apparatus with a wire of the same gauge as the ground, crimped & soldered ends. What I did notice is in Papajam's link it appeared in the photo the 12v wire was on the right side post of the pump and mine was originally hooked up to the left. But then the recall posting he made appeared to show the 12v on the left as I found mine. The new & old pumps have no markings whatsoever as to which is + & -.

I looked at the car briefly today and I thought the pump died again but when I bridged a 12v wire directly to the tank pump it works. I need to go completely through the tech stuff Tifosi linked me to as it covers stuff the manual does not. I wonder if I have a blend of a couple problems: one of which may be the fuel pressure regulator and the second may be the deal from the coil? that tells the brain to give the pump 12v. The problems are basically chugging, fall on face, fire, moments of clarity and chugging more to complete shutdown for exercise.

I bought a fuel pressure gauge and will try to get some readings later. Todays been a time with the wife day. I appreciate everyone at this site very helpful and knowledgable group. I think I may just start on page 1 of Tifosi's 48 page tech checks and go through and check everything as I need to iron it out for a trouble free winter. Maybe I can get mine to run 125 mph - grin, chuckle - ok I fell off my chair in my 60's flashback .........Seriously thanks a lot!
Matt A.