Fuel Pump?

[NDB]

Had a strange thing happen. I was in the parking lot waiting to get my car smogged and when I started the car to back out of the spot and park in the smog station, the engine started stopping and going until it ultimately stoppped. How do I know if the fuel pump is bad or not? I cannot hear anything when I turn ignition on or begin to crank. There is no fuel coming out of the feed line to the engine. How many volts should I see going to the fuel pump and when should I be able to see the voltage/when should fuel pump initially turn on? Do I need the leads to the pump off to check the voltage? Most of the common things I check were done in the parking lot so I was not sufficiently able to trouble shoot effectively and patiently. I think I've checked most of the common things that may cause the pump to not turn on. The voltage to the pump with the wires still connected to the pump was in the sixes. Is that normal? I'm not completely sure of the whole pump activation cycle, and what sensors effect pump operation. I just want to be sure it's the pump or not because it is a very expensive item just to swap out on a nudge. $200+.

Thanks

I have an 83 spider

[Joe Papa Sr]

turn on ignition so as to get voltage to pump, but not so far as to start engine, and put a volt meter on the 2 terminals of fuel pump. You should see 12 v on wire ends. If pump does not hum, /respond, Id suspect it is dead. Went through this on my 87 2-3 yrs ago.

Joe

[Joe Papa Sr]

You dont have to unscrew terminals for this test

[papajam]

Be aware that the L-jet system will energize the fuel pump for only about a half second when the key is turned on. Turning the key to the start position however should result in constant battery voltage to the pump.

[ghnl]

Your '83 should have the L-jetronic fuel & ignition system. Lots of info about it in the L-jet diagnosis page - link is in my signature.

First thing to check is for the presence of spark.

[MyVeloce]

First of all you have two pumps. One in the tank and one underneath the car. If you turn the ignition switch to the first position you should hear the pump in the tank going. If it is not going then it has to be replaced and it is possible the one underneath may also be gone.

[Munchen]

How's the fuel pump fuse under the rear deck by the ECU?

[philbtp]

Just went through that, if the pump is dead order from local auto parts store. I paid around 150, you may pay more from internet.
Dan

[MyVeloce]

Also check the condition of your gas tank inside. If there is a lot of crap and your first pump doesn't have it's little sock then it will just keep failing.

[NDB]

great, thanks so much for the feedback and info.

I checked the fuse and it is not burned through.

I'm thinking it does have spark because of the way it was sputtering and then eventually stopped, plus, I know its not getting fuel because it wasnt coming out when I disconnected the line to the regulator and/or the cold start injector and turned the ignition to ON and also during cranking.

When I got some info on the pump at the parts store, it was a 100-110 psi pump. Is that the correct constant pressure going to the regulator?

I have read that L-jetronic diagnosic web page, tons of info, I even printed some pages out to take to the car while I tried to quickly troubleshoot in the parking lot, but I wasnt able to effectively attack the possible issue of a failed fuel pump in the parking lot. I'll need to set the car on some jack stands and check these things in the comfort of my garage.

[Tifosi]

Quote:

Originally Posted by NDB When I got some info on the pump at the parts store, it was a 100-110 psi pump. Is that the correct constant pressure going to the regulator?

[NDB]

ok, so i ended up pulling the leads off the external fuel pump so i could get a better contact with the ends of the multimeter. I did get the initial blip of power when i turned the ignition on and was receiving sufficient voltage during cranking. was a little low though due the the car sitting for a while and the excessive cranking i was doing for troubleshooting. i ended up taking the pump off and wiring it directly to to the battery which was over 12 volts. pump was inoperative. you could feel it trying but it did not spin. so i bought a new one and replaced it as well as the filter and everything works fine. i think the failure could have been caused by the numerous of times i took sharp turns with a low fuel level causing the pump to run dry for many short periods of time.
well anyways, its fine now and runs good.

[ghnl]

Good news. Glad to hear you got it fixed.