3FE No Start Issue

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Other than the sickly sounding fuel pump everything else appears to be in working order. We are pretty sure that we are still getting fuel and the real issue is spark.

We'll get that other wiring spliced in and let you know how it goes.
 
jonheld said:
Is there a possibility of other problems? It looks like someone chewed through the wire.
Click to expand...

Hey Jon, I just want to let all the 3FE guys know that this could be a potential problem area for a lot of trucks... I just looked at mine and it's starting to look the same as James' (weasel65).

BTW James, good to see you on the board! Now make an intro thread! :flipoff2: <--official 'Mud salute
 
There shouldn't be any need to swap fuel pumps, it is much easier to just check fuel pressure and flow.

here's the fuel pump test condensed version. If you don't have the proper equipment, you can probably at least compare from yours to your buddies.

FUEL PRESSURE TEST


Check that battery voltage is at least 12 volts.
Disconnect battery negative terminal and the wiring connector from the cold start injector.
Disconnecting The Cold Start Injector Delivery Pipe







Remove fuel delivery pipe between Cold Start Injector and fuel rail. Use caution if the fuel system is still under pressure.
Connecting The Fuel Pressure Gauge







Connect a suitable fuel pressure gauge to the fuel rail using the union bolt and gaskets to provide a tight seal.
Wipe off any gasoline that may have escaped when the fuel pipe was disconnected and reconnect negative battery terminal.
Installing A Service Wire On The Engine Check Connector







Install a jumper wire between +B and FP of the check connector, turn on the ignition WITHOUT starting the engine and observe the fuel pressure gauge.
Fuel Pressure: 37 - 46 PSI (255 - 314 kPa)

If pressure is low, check fuel pump output and/or fuel filter for restrictions. If pressure is high, continue checking FPR.
Remove the jumper wire from the check connector and start the engine.
Disconnect And Plug Vacuum Hose To FPR







Disconnect vacuum sensor hose to Fuel Pressure Regulator, plug off the end, and observe gauge readings at idle.
Fuel Pressure: 37 - 46 PSI (255 - 314 kPa)

Reconnect the vacuum hose to the FPR and measure the fuel pressure at idling.
Fuel Pressure: 33 - 37 PSI (226 - 265 kPa)

If fuel pressure is not as specified, check the vacuum hose. If no problems are found with the vacuum hose, replace the FPR. Refer to Fuel Pressure Regulator.
Stop the engine. Check that the fuel pressure remains above 21 psi (147 kPa) for 5 minutes after engine shutdown .
If not within specification, check the fuel pump and/or injectors. If no problem is found, replace the Fuel Pressure Regulator.
Stop the engine and disconnect the fuel pressure gauge from the engine.
Using new gaskets, reinstall the fuel delivery pipe to the Cold Start Injector.
Wipe off any gasoline that may have escaped when the fuel pipe was disconnected.
Start the engine and check the Fuel Rail for cracks or signs of fuel leakage, especially around the fuel injectors.
 
Also, this may sound stupid, but make sure you have fuel. A fuel pump will sound significantly louder if it is in an empty tank. May have a faulty guage, so check for fuel at the rail, not the guage. Not sure if lack of fuel pressure will shut spark off, but someone else might know.
 
Thanks for the info.

If it still doesn't start when we get a new plug on, that'll probably be the next step.
 
Update

James has ordered a plug from Cruiserparts.net. Should be here in a few days.

We'll post up the results when it's soldered in.

:steer::banana::popcorn:
 
New plug in, and....Nothing.

Now what?
 
Would I be wrong to think that the AFM might be the culprit?

I only suggest this because we had found a small piece of metal lodged inside it...see post #33
 
I had to re-read everything again...

THe CE light is ON
Have you physically checked for spark at this point? Pull a plug wire and see. Spark + no start = no fuel

THe AFM throws the COR that fires the fuel pump. You could manually short terminals FP and B+ on the check connector and that will run the pump.
 
jonheld said:
I had to re-read everything again...

THe CE light is ON
Have you physically checked for spark at this point? Pull a plug wire and see. Spark + no start = no fuel

THe AFM throws the COR that fires the fuel pump. You could manually short terminals FP and B+ on the check connector and that will run the pump.
Click to expand...

That's right, that's right.... Scratch the AFM for now.

I know the truck is not getting spark, I pulled a plug wire to find nothing.

So here's a quick rundown of what we've done: Swapped ECU, coil/igniter, and EFI relay/fuse between trucks. Replaced the fusible links and faulty wire (post #10). Checked pickup coil on the dizzy.

All parts check out good, and still nothing. No spark and a sick-sounding fuel pump.
 
Lets go back to the beginning here. This truck was running and then the starter was replaced. He had to have missed SOMETHING or disconnected SOMETHING. The starter is on the same side as the distributor, AFM, and some wiring.

Shotgun replacement parts are yielding no love so I suggest a different approach.
Check Engine light is on so ECU sees what it needs to see to energize the EFI circuit, but no spark.

You need to physically inspect this area and all surrounding areas. SOMETHING CHANGED. SOMETHING HAPPENED during the starter replacement. What caused this “piece of metal” to become lodged in the AFM? WTF was he doing? You mentioned changing out the AFM. Might as well at this point.

Lets start doing basic continuity and logic checks.
Key in the ON AND START position: logic high: B+ (pin 3) on Igniter AND Pin 1 of Coil.
Key START position: logic high ECU connector E4-15; E4-2.
ECU ground points: E4-13;24;26; E5-16

Make certain that the igniter/coil combination has a good solid ground.
Make certain that pin 1 on the AFM is ground. Double check TPS connection.

Key OFF: Continuity checks from:
ECU connector E4-3 to Igniter IGF (pin 1); E4-22 to Igniter IGT (pin 2); E4-4 to Distrib NE; E4-18 to Distrib G1; E4-17 to Distrib G-;

Both the AFM and TPS receive control voltage from the ECU E5-1.

Check continuity from E5-1 to AFM pin 4 and TPS pin 1. Then check the voltage on both pins with Key in ON position.
 
You say you pulled a plug wire and found no spark. Have you checked if you have spark from the coil?

The only reason I ask is the :princess:'s POS SAAB just stopped last week while I was driving it. It turned out to be the rotor button earthing back through the shaft! Had spark at the coil but no spark at the plugs. Relpaced the rotor button and it fired 1st swing.

FWIW I tend to agree with the 'something has changed' line of thought, but this is worth a try.
 
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We're not getting spark at the coil. I pulled both a plug wire AND the wire going to the dizzy. Nothing.

We know the coil is good because we used it to start my truck. Same with the ECU and EFI relay.

James is out of town for the week, so we won't be able to work on it...
 
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I almost forgot about this...

James father took the 80 to the dealership, where they determined (after telling them all we've done) that the distributor needs to be replaced. Honestly, it's the only thing that we didn't check. :confused:

Anyway, his dad ordered a dizzy assembly from Cruiserparts.net, so we'll see how it goes from there.
 
I'm not sure what they did. I don't remember checking the dizzy myself though, so that must have been the culprit.

No word yet, hang tight guys....
 
BIG UPDATE

IT RUNS!!! :D

Turns out the issue was with the AFM. Dealer replaced the dizzy, nothing. Replaced AFM as an "oops, that didn't fix it, we'll do this labor for free" type of thing. Fired right up.

Whew. After all that, it actually WAS the AFM.
 
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Good to hear.

After my no start issues, and multiple, multiple, multiple re-soldering of the AFM, I finally replaced mine with a use unit from Specter; no more problems.

But let me get this straight, the dealership replaced the AFM with a brand new one for no cost to your buddy's dad? That is an $800 item right there!
 
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