Tow Job

[4uall]

Hope it gets sorted out for you soon

Keep sending the nice weather east

[majicwrench]

Testing the fuel system while car is running well is going to tell you nothing. If car runs well it has enough fuel pressue. I would certainly note, however, if you can hear the pump running.

I'm also curious, what did you pull off the CSI??

Really, to do any effective troubleshooting, car has to be dead. Run it till it dies. Drive it around, park at house, wait, try to start. If it won't start YEAH now check for spark again, just to be sure, then crack the fuel line at CSI and crank engine. Fire extinguisher handY?? Fuel should spray.
If no fuel, now you need to check power and ground at pump. If you have power and ground, bad pump. If no power or ground, fix that.

Giving a inop fuel pump a good whack often gets em running again.

[courtenay]

Keith - I pulled the electrical connection off the CSI. I thought I had read on another thread that this might help. Obviously it didn't. I did test for spark with a spare plug when the car wouldn't start after I was towed home - I had spark. I also removed one of the plugs from the engine and it was dry, even after a lot of cranks.
I understand that attempting to test the fuel system when the car is running probably isn't going to show anything. I'm going to spend some time driving around our neighbourhood on the weekend to see if I can get the thing to shut down again - close enough to home that I won't need a tow truck - and then run the fuel system diagnostics.
Thanks for the help...
Bruce

[majicwrench]

If you really want to be prepared, run some wires from fuel pump power and ground into the cab, then hook up voltmeter. Obviously should read 12v+ when car running. If car won't start you can instantly see if it looses voltange.
Is you car wired correctly, where pump only runs when cranking?? Or does your pump run any time key on??

As far as spark, I'm just anal about double checking things like that, keeps one from chasing your tail.

Looking forward.

[wizard124]

A quote from my FIAT "Fuel Injection System" technical training manual. Regarding the fuel pump:

"The DC motor is totally immersed in fuel for lubrication and cooling." "Pressure in the system is always maintained and excess fuel flows under low pressure back to the tank. This prevents the formation of vapor bubbles." "The pump contains ball check valves which provide excess pressure relief and pump priming".

A couple of thoughts. Are you sure the fuel return line is clear? If it isn't maybe the cooling isn't sufficient and the motor stops?? Or, these ball check valves are mucked up. Have you tried a fuel system cleaner?

[courtenay]

Good suggestions Keith - I will hook up a V meter to the fuel pump and once I get the thing to fail again, I'll recheck the spark. Going to try and find some time this weekend to play with it. As far as I know, my pump only runs when cranking. I certainly don't hear anything when I turn the key before cranking.Have about an acre of lawns to cut today and tomorrow as it's supposed to rain on the weekend...
Thanks for that Wizard.

[narfire]

Bruce, how's the ground connection for the fuel pump? I'm trying to remember if it connects to a ground at the rear driver light. Had your golf clubs rolling around in the trunk lately?
As it is a long weekend, the weather is changing to its usual weekend cloud and rain after a week of hot sun.... I'll mail the radio...
Not coming over this weekend...
Chris

[DaveHoliday]

Bruce,

I have been having a similar problem with my 81 spider. I have a post up but haven't heard back yet. My car shuts down after driving it for 15 to 30 mins...almost as if it is running out of fuel. I have found that my gas tank builds up pressure (NOT suction) and removing the gas cap to release the pressure will allow the car to restart....might not be related to your problem...just passing along a similar scenario that i have dealt with.

[courtenay]

Thanks, Dave, I'll give that a shot once I can get the car out on a warm day. Unfortunately, a sole bunch of other things have gotten in the way of getting at my Spider problem. However, once I can get a warm day where I can drive around the neighbourhood (don't want to get too far from home with this problem) long enough to re-create the problem I'll give the gas tank pressure relief a try.
I guess the big question is what the cause of the problem is that can be solved by taking the gas cap off?

[courtenay]

Well, it's been awhile since I've had a chance to get back to my car. Since I had the problem, we've spent a month in Europe followed by 6 weeks at an RV/Marina resort on Northern Vancouver Island. Both trips very successful - I now have enough salmon and halibut to get our family through 'til next season!
Anyway - back to my Fiat. The car started right up after sitting for the past couple of months. Before I started it, I turned the key to the run position and opened the flap on the AFM and the fuel pump ran. I let it warm up on idle for a bit then drove around the neighbourhood for about 20 minutes and returned to the garage - it's a very warm day here and the car was well into it's proper operating temperature.
Shut it off, and it wouldn't start. Tested for spark - it was good.
Turned the ignition on and moved the AFM flap and while I could hear a click under the dash, the fuel pump did not turn on.
Something in the system somewhere is preventing the fuel pump from engaging when the car is warm.
I am appealing to the gurus on the forum to suggest what I should try next.

[RRoller123]

bad double relay sounds like

[courtenay]

That's kind of what I'm thinking as well after doing some searches. Question though, is it possible for the double relay to work when the car is cold and then fail when it's hot? - because that is essentially what is happening.

[81SPIDERMATT]

a failing fuel pump will imitate your symptoms also ... to be sure you would need to test the voltage at the pump ... if you are getting good volts at the pump than most likely the relay is doing its job ... if no voltage then I would suspect the relay

[MrWampus]

I always learn new things here. My fuel pump runs when I turn the key to the first position. I can here it clearly prior to turning to crank the engine. How was mine wired differently than it is supposed to be? What do I look for? Is this a common bypass on FI cars? Could this contribute to my poor MPG?

[RRoller123]

It is common for the pump to be wired to run with the ignition on, (likely done when the double relay failed at some time in the past). It is done by bending the contact arm under the cover on the AFM. Not a problem, but would be good to install an inertial shutoff switch to shut off the pump in case of an accident. You can read Brad Artigue's EFI manual for details on the pump on/off action. If you search the forum you will see multiple posts on the inertial switch too. It is a common mod, and has no effect on mileage.

Pete