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Discussion Starter #1
Hi guys, hope everyone has/is having a nice Holiday week.

I am still dealing with a persistent low fuel warning light issue that I could use some help with. It is intermittent and drivability is impacted, so it is an accurate warning in the sense that it is telling me that I have an issue. I can drive around town without issue but sustained highway driving has the light come one as a flicker, then mostly illuminated, then constantly on and shortly after that she will start to cut out if you give her more than 1/2 throttle. I do understand that running her without adequate fuel pressure is an unhappy thing for the SPICA so I do not actually drive her around like that.

She has had two new rear fuel filters in under 200 miles. She has an under 300 mile new correct high pressure fuel pump. I do not believe I have a hot fuel issue, my test for fuel venting issue was negative.

I did try pinching the return fuel line per Wes Ingram's site and that does extinguish the warning light. I have not tried to drive her with the return fuel line restricted, the test I did was at idle. Per Wes that seems to suggest the injection pump is failing, correct? If so, that means a full SPICA rebuild?
 

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Caveat - I am not well versed in SPICA. But I believe the fuel pressure warning light indicates inadequate fuel supply to the SPICA pump, not from the SPICA pump.

see: http://www.alfabb.com/bb/forums/att...ides-spica-roadside-fault-analysis-ver-1a.pdf

I. SYMPTOM:
Flashing or steady fuel low-pressure warning light. (See section on Fuel Supply System Fault
Diagnostics for a more in-depth troubleshooting procedure)
POSSIBLE CAUSES:
1. Clogged fuel filter.
2. Weak or failing fuel supply pump.
3. Fuel overheated causing supply pump cavitation.
5. Clogged (suction) fuel line from tank to pump.
4. Fuel tank vent clogged.
 

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You mention replacing the rear fuel filter twice. Have you taken them apart to see if they were clogged? Could be crud in the gas tank that clogs up your fuel filter real fast. How about the front fuel filter? When was it last replaced?
 

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Discussion Starter #4
Hi guys - thanks for the responses. I have not cut open the prior rear fuel filter so I do not know for sure if there is crud in the tank. I suppose I could throw another rear filter on there. The front filter should be under 300 miles new. That would make it unlikely to be the cause, no?

While the "pinch the return line trick" is in the return side of the flow I believe it raises the back pressure on the inbound side there by raising pressure in the pump as well. Maybe someone could check me on that?

Thanks guys!
 

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Yes. If you clamp off the return line you dead head the pump which raises the pressure. My three suggestions are 1. If you still have one of the rear filters you took off cut it open and look inside of it or you can blow through it. 2. If you don't have the filter or want to check anyways remove the fuel sender and look in tank to see how bad it might be. 3. Take the front filter head off and apart make sure its completely clean inside. You can also remove the hose nipples from the injection pump and make sure the orifice isn't partially stopped up.

One last thought. If you have any fuel lines that are older then 3 or 4 years and you have been running that wonderful ethanol gas. There's a good chance that one of the rubber lines is swelling up inside. Because there not ethanol resistant. If you don't know the age of the lines replace them all and when you do blow through the metal lines to see if there restricted. If the cars set a long time the old gas will turn to varnish and harden up in the metal lines reducing flow.
 

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Hello,

I would go for:

4. Fuel tank vent clogged.

Did you try to open the tank filler cup as soon as this is happening?
From your symptoms there should be a vacuum in the tank.

Look at this one:

Low Fuel Pressure Light

Good luck

Bernhard
Hello Bernhardt, thank you for the reply. I did open the fuel filler and there was no vacuum / whoosh when I opened it. Was hoping that was it!
 

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What exact Fuel Supply Pump did you install?

The replacement pumps that we use today, usually L-Jet type pumps (OEM originals NLA), can sometimes require that you narrow the restrictor in the outlet fitting of the Injection Pump in order to keep the fuel pressure up under all conditions.

Go to Ingram Enterprises, Inc. || Spica Pump Rebuilds and download the Fuel Supply Diagnostics Guide there. It explains all this.
 

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I am still dealing with a persistent low fuel warning light
Is this persistence pre or post electric fuel pump replacement and exactly what electric pump is the correct pump? Does your model year Spider have an electric in tank supply pump?
 

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Discussion Starter #11
Low fuel tank levels can make this worse. Does it happen with a full gas tank?
I have not tried filling her up, she has fuel in her still but under 1/2 a tank. Will give that a try after replacing the rear filter with the recommended WIX one.

The Spider in question is a '73 and I used a recommended pump, will need to double check the specific brand and model number when I am under the car today.

Does anyone have a picture handy of the outlet restrictor Roadtrip mentions?

Thanks guys, appreciate the help.
 

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Discussion Starter #13
Think this might of had something to do with it?

You guys nailed it - especially Jim G.



 

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Wow! That is serious debris!
 

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Discussion Starter #15
Wow! That is serious debris!
I was pretty surprised too, I've not seen that sort of scale in a fuel line before. Wonder how many filters before that shedding is over? Still, beats it being something else in the fuel system.
 

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You will want to take a look inside the tank and decide from there how to proceed.
 
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