Does the fuel pump prime - key on?
11-23-2008, 01:48 AM
#16
Team Owner
the box was probably something rigged up to work a O2 sensor for the engine system to pass EPA regs
11-23-2008, 06:29 AM
#17
Rennlist Member
It was a wierd box as it clearly has 6 power transistors with high wattage load resistors....... ?
Was it is series with any leads to the LH or just tapped into the harness ?
Let's hope it hasn't blown up both the LH ECUs you have used....
Did you check the injector wiring and resistances ?
Was it is series with any leads to the LH or just tapped into the harness ?
Let's hope it hasn't blown up both the LH ECUs you have used....
Did you check the injector wiring and resistances ?
11-23-2008, 09:11 AM
#18
Race Car
He needs to find out which wires it's connected to before he starts pulling things off. From what little I can see looks like the wire is cut so it is in series. Put a Ohm meter with the box disconnected on the connector see which pin it goes to on the Lh then stop guessing. Then look up the Lh pin out, if it's an add on it can be bypassed by reconnecting the original wires then you will know what its purpose is.
11-24-2008, 12:04 AM
#19
Rennlist Member
Guys, both my USA 84's pressurize the fuel system on turning key to the run position the first time I turn the key after they have sat.
The pump clearly is running for a couple seconds, both cars.
Just happened in the basement. I have a loose connection on the fuel rail (leak). I turned the key to roll-up the windows to keep the cat out. Fuel pump ran, gas starting dripping from the fuel rail again. (Good news is I saw and fixed the leak).
So, is L-Jetronic different? Cold-start circuit of some sort? I hear that pump run every time. Its not the antenna motor ( its out ). The hatch motor is out. All insulation and carpet is out in the back. I hear it clearly and just saw the results. Am I crazy?
The pump clearly is running for a couple seconds, both cars.
Just happened in the basement. I have a loose connection on the fuel rail (leak). I turned the key to roll-up the windows to keep the cat out. Fuel pump ran, gas starting dripping from the fuel rail again. (Good news is I saw and fixed the leak).
So, is L-Jetronic different? Cold-start circuit of some sort? I hear that pump run every time. Its not the antenna motor ( its out ). The hatch motor is out. All insulation and carpet is out in the back. I hear it clearly and just saw the results. Am I crazy?
11-24-2008, 12:29 AM
#21
Rennlist Member
'85928. I also want know about the "louder" pump when jumpered. The only time I can hear it is when I happen to be re-connecting the batt and I'm standing there, just a huuuuummmm. I had occasion to jump the FP relay and it was much louder at the driver's seat, hatch closed, very obvious. If the engine were somehow to run silently, would you hear the pump at the level all the time? Does the line pressure cause the pump to work that much harder than what we normally hear when powering on?
11-24-2008, 12:42 AM
#22
Three Wheelin'
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Mine all run for a couple of seconds when I release the key from start on all the cars. The only time they are ever loud is when I'm real low on fuel, or just before they burn out
I noticed on the Euro that the pump would seize from overheating when I would thrash her and the engine started getting warm, or if I was running very low on fuel. If I let the pump cool, or fill full of cool gas, it would run again for hours. It seemed to be strickly a heat problem from the returning fuel. Replaced that pump and all is well....
I noticed on the Euro that the pump would seize from overheating when I would thrash her and the engine started getting warm, or if I was running very low on fuel. If I let the pump cool, or fill full of cool gas, it would run again for hours. It seemed to be strickly a heat problem from the returning fuel. Replaced that pump and all is well....
11-24-2008, 01:18 AM
#23
Team Owner
part of the fuel system is routed through the AC system this is a system to cool the fuel , so you may find that after driving for a few hours usually slow driving, (this lets more of the fuel return to the tank after every pass, and it gets heated every pass) the AC is supposed to cool down the fuel but a few AC systems dont get run so the fuel gets hot and so does the pump thus it makes more noise.
Filling up with fresh fuel should cool things down plus running the AC while the engine is running will also help
Filling up with fresh fuel should cool things down plus running the AC while the engine is running will also help
11-24-2008, 01:35 AM
#25
Inventor
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LH2.2/EZF engines take a few more revs before they fire up. The EZF has to have a strong signal from the crank sensor, then it sends the LH a rpm signal, whereupon the LH activates the fuel pump relay. I think the LH doesn't even open the idle control valve until it gets an rpm signal.
11-24-2008, 10:22 AM
#28
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My cars fuel pump does not run when you turn key to on ,But i have noticed is does if you cycle the headlights with key on.....now that seems strange (its a 82)
I used that trick to re pressure fuel system after i had it apart
I used that trick to re pressure fuel system after i had it apart
11-25-2008, 05:43 AM
#30
Rennlist Member
...... and it wasn't connected to anything else ?
Did you check the injector wiring ?
Give us a status report. so we can help you.
Fuel pump runs when engine is cranking ?
12v on pin 13 when igntion is on ?
Did you check the injector wiring ?
Give us a status report. so we can help you.
Fuel pump runs when engine is cranking ?
12v on pin 13 when igntion is on ?