928inAtlanta

Before I do something really stupid (like sell her!), I'm begging for some advice.... here is the story:

Car is a 79, and was running perfectly. Then 1 day, it starts, runs for 30 seconds, and dies. Won't start again (will die after 1 sec.). Replaced the fuel pump fuse. Won't start. Replaced the fuel pump relay. Still won't start. Replaced the fuel pump (which was old). Still won't start. Then I actually did something smart, and broke out my DMM, and found that there is no current at the fuel pump. Jumpered the fuel pump relay, and still no current (and no current at the relay socket either). Connected the pump to a 12v battery just to double check, and the pump is fine. But the car will start for 1 second only, then die (I'm using a separate power source just for the pump, so the pump is running).

So basically, I've got no power through the pump relay socket, and even when I run the pump from a different power source, the car still won't run --- but was previously running great! The power accessories in the car are working. The tachometer comes alive when the car runs for that second. I'm inclined to think that I've got some type of wiring/electrical problem --- does this sound like some simple thing I'm overlooking?

Right now, I'm totally frustrated, and will be eternally grateful for any guidance!!! Any suggestions are definitely appreciated!!

JP Rodkey

You don't write whether you have the WSM or a fuel guage. The good news is your '79 is like most other cars of that era, meaning you don't have to bother with a computer. Go with the basics - fuel and spark.

1. Check for spark first. Use the old drill of pulling a plug wire and having someone crank the engine.
2. Assuming you've got spark, the ideal would be to hook up a fuel pressure tester. Unfortunately, you really need a tester designed for the Bosch CIS because of the fittings. You can certainly check for the presence of fuel (like at the return line off of the fuel distributor), but it's pressure you really need to monitor.
3. For a simple test, after cranking the engine, you can push down on the control flap under the air cleaner housing. It should offer resistance, indicating you have fuel pressure.

There are so many variables here that it would be best if you can verify whether you have ignition problems or if it's fuel. Your problem sounds like ignition to me. See if you can futher isolate and report back. Lots of folks will help out.

3000teeth

I know this sounds stupid, but check the battery. Is it fully charged? This has been a big problem for me --all kinds of stuff goes wrong if the car sits for awhile and the battery loses volts.

928inAtlanta

The battery is new in the car. Problem is very frustrating!!! Car is a CIS model, and was not sitting -- it was driven regulary, and driving quite well. It did not gradually start running like crap, then die...it went from running great, to not running. When I try to start the car, it will start for 1-2 seconds, and then die. Then for each immediate subsequent attempt, it won't start. If I walk away for 10 minutes, then try to start the car again, it will start for 1-2 seconds. Does this give anybody a clue as to what the cause might be?

928BC

It sounds like it's running for only a couple seconds on the coldstart injector. The ignition module I think has a signal that can cut power to the fuel pump relay if it thinks its over 6300RPM. this might be your problem or your green wire from the distributor to the ignition module might be grounding out.

Dennis Wilson

When you checked for power was it the 30 pin or the 15 pin? If no power to the 30 pin, check the connectors at the bottom/center of the fuse panel for corrosion. If that appears OK and still no power, check the jump post under the hood and the battery connections at the starter. If there is power to the 30 pin but none at the 15 pin, the ignition switch is probably bad.

Dennis

SMTCapeCod

OK, my post disappeared!
Work with Dennis, he helped me to diagnose a bad circuit in the TSZ module. The safety circuit that runs the fuel pump.

Mrmerlin

Did the car get wet before this non start issue happened, if so check all of the wires going to the CE panel and under the hood at the hot post and open the back of the 14 pin connector at the hot post look for corroded wires also look at the CE panel for water leaks they will either be rusty orange or chalky white running down the securing rails if so try removing all the relays and replacing all the fuses if this is the problem then you need to reseal the bottom of the blower box before the car gets wet again also check under the hot for the ignition box check these connections and as always disconnect the battery before doning any checking for corrosion

RicerSchnitzzle

One more thing to check.

I had the same symptoms with the start and die, then no start. Turned out to be the distributor cap was cracked and grounding to the block. New cap and VROOOM! Turn the lights off in the garage and look for stray sparks from the cap, most likely near the hold down pins.

Shark Attack

FWIW, My 79 fuel pump ran as soon as I turned the key if the car was running or not. And the FI on mine was not electrical. If you put power to the pump, does the car run then? Its strange you have no power to the relay socket.

Im looking at the wire diagram now, do you have power at fuse 22 ? Make sure you are on a good ground with the DVM.
on the relay did you jump post 30 and 87?

928inAtlanta

I'm still dumbfounded...but have a question for the experts:

Could a bad alternator be the cause? To me, the perplexing issue is that I am finding no power at the fuel pump fuse or relay. Could the alternator somehow be at the root of the problem? I admit that my skills are limited, but there has to be something that is causing a lack of power at the relay. The car was driven regulary, and never in rain.

Sean79 5spd

I suspect this is related to an ignition issue not a fuel issue. I can't remember all the details but the ignition box controls power to the fuel system. If ignition does not occur power will be cut to the fuel pump. I would go over all the components of the ignition system including, the ballast resistors, green wire, coil, pickup in the distributor. Also check for corrosion in the 14 pin connector (pass side engine comp)

michael j wright

O.K. 928inAtlanta said that he ran seperate power sorce to pump- so he should be getting plenty of fuel. My car has done this same thing in the past also- turned out that I had alot of junk get accumulated in the fuel dist inlet screen - thats where I would look first - very simple to check and clean- just my 2 cents -Mike

928BC

If you are finding no volts at ethier side of the fuse using a good ground(don't take the reading in parrallel with the fuse) then check termial A1 on the A connector at the bottom left of the fuse panel. If not, like Denis was saying the ignition switch is at fault. Looking at the W. diagram anything controling the realy will have nothing to do with having power at the fuse or at the 30 terminal on the fuse board realy socket.