HELP!! Old wise and knowledgeable FI gods

[kuhndg]

Today we finally tried to fire up Antwan. After working through all the little electrical glitches and everything else that comes with a novice tackling this size of project, you guessed it.....won't start.

Here is what we have done.

First, the car is a 1980 FI.
Total engine rebuild
Mark's header and exhaust
air box deleted replaced with cone element
replaced plugs and wires
ignition coil and module new.....yes there is spark
replaced the cold star valve
injectors were removed and sent out to be tested and cleaned
not that this matters but the alternator has been rebuilt
all of the sensors replaced
YES, the fuel filter has been replaced
YES the timing is set correct

We think it is most likely not getting fuel. We did try a small amount of starting fluid and it started and burned that up. at that point we came to the fuel conclusion. Can't remember, does the fuel pump start to run when the ignition is keyed? Mine does not. I am no pro here by any stretch of the imagination and would appreciate anyone that can step forward with any knowledge that can help get this car running. Rather than waste anytime, thought it was best to turn to the wise ones.

Thanks in advance,

Bob

[So Cal Mark]

the fuel pump won't run until the flap in the air flow meter moves. With the key on the air filter box opened up, push the flap by hand and you should hear the pump.
A really common occurence with a engine swap is the ground wires that attach to the plenum. Those are the injector grounds, must be grounded or the injectors never pulse. The other thing to check is the wire to the - side of the coil to the ecm. Without that, the ecm doesn't know the engine is turning.

[pope]

Just to make a small correction, the fuel pump initially is operated by the ignition and handed off to the airflow meter by the computer after the car has started for a few seconds. So the car should start regardless of the airflow meter flap, it just wont continue running. The flap is a good manual way to see if the pump will energize.

This switching is all controlled through the dual relay.
Does pump work when jumped by direct 12 v source?
Is the 30 amp in-line fuse for the pump any good?
Is the dual reply working?

Try these after Marks excellent suggestion.
A fuel injected motor is sometimes harder to diagnose because of all the related functions that rely on each other.

[pooldoctorstl]

After you do what Mark and Pope said you should have injector pulse. If it still doesn't start and you have verified that the fuel pump is running, pull out the cold start injector and lay it in a container then crank it and you should get a fuel spray while cranking (be careful and don't catch anything on fire!). If not, put a gauge on it and check the fuel pressure. You never know, you could have a bad pump. I don't mean to offend you, but you said the timing was correct but someone in a past thread had the distributor in wrong after a rebuild. Easy to do because the rotor should point to #4, not #1 when all of the marks are lined up.

By the way, was it running before the rebuild?

Jeff

[So Cal Mark]

Pope, the Fiat does not power the pump initially, The engine has to be cranking.

[pope]

That is right. The key actually has to turn to the start position. This energizes the pump portion of the dual relay to start the pump, but at this point, it is independent of the flap, and only operates as long as you are turning the key. The ECU keeps the pump on once the car has started and hands over operation to the flap.

[rlux4]

Have you checked that you have injector pulse? No pulse; as Mark says, make sure the two ground wires are secure on the outboard side of the intake plenum.
Have you checked for fuel pressure? Is your fuel pump running? If not, check the inline fuse Pope mentioned. It is on a brown with white stripe wire located in the rat's nest of wires up behind the fuse panel.
The dual relay has to be good, to check it this helps;
http://www.wcmotors.com/personal/Fiat%2 ... agnostics/
Ron

[launieg]

Pope, that is not my understanding. On my car, the pump is only energized when the flap on the AFM is at least partly open (not shut). The key activates the starter and turns the engine over, that draws air through the AFM, the flap opens, and the fuel pump runs, in that order.

As for help, I suggest that you disconnect the hose from the cold start valve (injector) and put it in a water bottle, turn on the key to run (not to crank the engine), open the AFM by hand, and see if fuel is being pumped into the bottle. You should also be able to hear the pump running (sound coming from behind the driver's rear wheel). You need to verify that you are getting fuel the to the fuel injectors when the AFM is open and the ignition is on.

[pope]

Launie, If I were you, I would'nt turn that in as a final exam answer. You might have to take the class over in summer school. Though you might impress the MG guys with that answer.

[ga.spyder]

The fact we can get a spark w/o smoke is impressive to the MG guys.

[So Cal Mark]

MGs have FI? it must not be electronic!

[launieg]

That is right. The key actually has to turn to the start position. This energizes the pump portion of the dual relay to start the pump, but at this point, it is independent of the flap, and only operates as long as you are turning the key. The ECU keeps the pump on once the car has started and hands over operation to the flap.

I won't pretend I know more about these cars than you. In fact, I know that I don't. But if the pump is "independent of the flap" until the car has started, then why does the pump run if you do not start the car, but merely turn the key to the run position and then physically hold the flap open? You said it

only operates as long as you are turning the key

But I'm not turning the key or starting the car, yet the pump runs.

I will agree that it is possible that the pump is energized in a special way (and even that the flap signal is disregarded) during cranking (in which case my earlier statement is wrong). It would be interesting to know why it would be engineered that way. I've looked at the wiring diagrams, but the problem is that the ECU is still a "black box." And I'm not a whiz at reading those diagrams either.

I've been to summer school. It can be a lot of fun

[pope]

Launie, you figured it out! NO summer school for you. But you would have liked my 7th grade teacher. Had I'd known that then, I would have acted dumb for a quarter to get some tutoring.

Most people assume that by pressing on the flap, it turns the pump on. What it really does is indicate to the computer that there is air flow and the engine is running, so KEEP the pump going. The other thing it does is turn the pump OFF, but only at a specific time. Since the pump is independently powered, the pump keeps running till you turn the key off. If you got in an accident and the engine stopped, but the key was still in the on position, the pump would still run and possibly rupture a line and high pressure gas could cause a fire. By having the flap close with the engine stoppage, it shuts the pump off as a safety feature. (This safety feature is what you experience when you have the key on and move the flap, by letting it close, it shuts the pump off). There is no pump ON at the flap, only KEEP GOING and SAFETY OFF.
There are two relays in the dual relay and one is for the fuel pump, activated by the key in the start position.

The reason it was engineered that way, was to have the entire fuel injection system started from one point, the dual relay.

[spider2081]

When troubleshooting there are always different paths to take. If I understand you are questioning if it is lack of fuel that is causing your car not to start. I like to take the black cover off the air flow sensor and visually check the freedom of the flap and look at the fuel pump relay switch contact. They are open contacts and easy to see. Opening to flap just a little should close the contacts. If you turn the ignition switch on and move the flap you should hear fuel relay click and the fuel pump run. If you do I would disconnect the cold start valve fuel line and connect a hose to the line to collect fuel in a pail. I then move the flap and see if there is fuel flow.
If I hear the relay click and didn't hear the fuel pump run I connect a volt meter (or trouble light) to the fuel pump wire terminals at the pump. Connecting to both terminals at the pump checks both the voltage and the ground. lWhen the flap is moved there should be 12 volts across the terminals. If there is, the pump is most likely frozen.

Please keep us advised of your progress

[rlux4]

Pope, you silver tongued devil, you! You got a way with words. Very good explanation.
Ron