19 replies to this topic

[ralt12]

Here's the issue. Parked the car ('95) in the trailer, running fine. A week later, I go to pull it out, and it won't start. Initially turns, but then shuts off. ( cranks with no problem) No fuel from the sample port, so I take the access cover off the fuel tank, and jump the fuel pump with a couple of test leads, and presto the pump works. Hit the master and then the ignition ket, and no power to the fuel pump. Replace the fuel pump relay, and it still won't do anything other than a little brrmmm, then dies.
Anyone run into this before?

[Keith Novak]

When you say no fuel from the sample port, was that with the pump jumpered in the diagnostics box?

[ralt12]

No; not sure how to do that.

[Keith Novak]

Open up the little black box in the engine compt right by the upper LH shock mount. Same place you use when doing the timing. The pin positions are listed inside the cap. Put a wire or paper clip between FP and GND. It bypasses the relay. Switch the key on and you should hear the FP whir. That's how you drain the tank with a test port. You can actually run the car that way. I've forgotten to remove it more than once.

That can help you isolate the problem from something pulling too much load off the electrical system to get a good start up and the alternator running the system.

[ralt12]

Thanks, I'll give it a try when it's under 100 out...

[Jamz14]

I had this same issue. Check all your ground points. Especially the ground at the rear of the PPF. As others have noted, don't just wiggle it. Disconnect, clean, and re-tighten .

[ralt12]

Won't start by bypassing the relay in the engine compartment. Ground checks are next.

[Keith Novak]

I didn't mean see if you can start it that way. I'm trying to help rule out the easiest stuff.

You tried to start the car and no fuel came out. Then you jumpered the fuel pump directly and it worked. You didn't say if it worked when you just jumpered the box and just turned the key on. If the key did turn the pump on when you're not trying to start the car, my guess is it's not the fuel pump circuit. Something is going on when you try to crank the car.

The car sat for a week between when all was good and when it wasn't. When you crank the car, it draws a lot of juice from the battery. If the battery is low which can happen over a week, it won't start but it may crank. It may not pump fuel either since it could be pulling enough to the starter that there's not enough to run the pump too. If the battery is fine, the juice has to go through the kill switch. Those go out sometimes. Another easy check would be to bypass the kill switch. The current has to return to the battery so the ground on the PPF is a likely culprit too.

[davew]

Couple quickies

Is the fuel test port on the input side of the fuel rail. If it is on the return side you will have no pressure and no flow. Fooled people before.

Instead of throwing parts at the car, get a shop manual and a wire diagram and see how the system works.

Do not believe any of the well intentioned people on the internet. Grounding the FP circuit does not bypass the relay, it only grounds the relay to turn on the fuel pump under conditions that the pump would not normally run. The relay is still in the circuit.

Do you have spark? No spark and no fuel will be a different diagnostic path than just no fuel.

Dave

[Keith Novak]

I bet $10 I could hook up jumper cables and bypass the kill switch faster than someone can find the right page in the wire diagram.

[davew]

I bet $10 I could hook up jumper cables and bypass the kill switch faster than someone can find the right page in the wire diagram.

And that is my point exactly. The car cranks so that pretty much rules out the master switch. And the master switch would not be in a wiring diagram anyways. I know you are well meaning, but in the case of this post (and this post only) it is not helpfull.

All too often we get this type of question. But we only get 10% of the needed info.

Your question, my car won't start? I want to know:

Does it crank over normally?
What is battery voltage?
What did you just modify or fix?
Does it have fuel pressure?
Is the fuel pressure test port on the pressure hose?
Does it have spark?
Does it have noid?
Do you hear fuel pump running?
Does the engine have compression?

All of this requires 5 minutes of time and can save days of questions on the internet

Using this case as an example. I will assume(for arguementive purposes) the test port is in the pressure hose and the car really has no fuel pressure. Also it has compression, so the motor mechainics are not the problem.

If you have spark and noid, the computer system is at least partially working. If you have no spark and/or no noid, you have an electronic issue with the engine management. If you have spark and noid the problem is limited to the fuel pump circuit.

You have 2 wires that feed the fuel pump. 12 volt power and ground. Do you have ground? Do you have power when initially turning on the key? After a few seconds you should loose the power. Now you can start figuring out which part of the circuit to diagnose using a wire diagram.

As another note, just because you hear a relay click does not mean it is working. Relays have 2 seperate circuits. The small wires are switched by something else (ECU in this case). That is the click you hear/feel. The controlled circuit is normally the larger wires and inside the relay are a pair of contact points (just like an old Chevy) The contacts wear and corrode. They live in a pretty harsh environment, in that the voltage is arcing every time the contacts get close. This can easily cause relays to corode and fail.

Sometimes throwing parts at a problem is the best way to fix it. But that is rarely the fastest nor the most economical.

Dave

[Bench Racer]

Dave, you have a fuel pump e-mail. pm box must be full.

[Keith Novak]

All too often we get this type of question. But we only get 10% of the needed info.

That's my point too.

So far he determined the car won't start. The FP runs if you apply power directly to it. No fuel comes out the test port when you crank the car. Not much to go on. I usually start looking at the easiest things to check and rule out one by one that don't involve changing parts before digging in too deep. "It aint got no gas in it." Is the battery low? When you jumper the FP do you not just hear a click but the pump whir, a squeaky noise in the rail as the fuel starts flowing and fuel pumps out when you're drawing almost zero current from anything else?

My questions were to try to pin it down a little more than that. I figured there could be a couple really obvious culprits if you ask a couple easy questions that take minutes to check so how about we rule those out first.

Your list of questions is great. It would make a great sticky..."Before you ask why your car won't start or runs then dies..."

[Bench Racer]

I sent an e-mail to Dave Wheeler with reference to the fuel pump issue to confirm the message below. The message is true for my 1990.

EDIT:

I am one of those well intended people Dave Wheeler talked about.

Today I viewed the wiring diagram for the 94 & 97 1.8l car which has only one coil in the fuel pump relay.

The 90-93 has two coils in the opening circuit relay.

[ralt12]

As sudden as this came, it left; I cleaned the ground connections, then the fuel pump still wouldn't work. rechecked all the connectors--and I mean all the connectors, a real nut and bolt job--and it runs again. Don't know which it was, but it is a little strange.

[George Munson]

This is probably a dumb question, but what is "noid"?

[DES4]

This is probably a dumb question, but what is "noid"?

Not a dumb question at all. A "noid" plugs into the fuel-injector connector and flashes while cranking the motor to confirm you have an injector pulse happening.

[George Munson]

Thanks, it looks like another tool to add to my collection.

[TEAM MEDICARE]

Where does one purchase a "noid"?

[Bench Racer]

Where does one purchase a "noid"?

Please get purchase directions from Mr. Google.