Yes, i rather use the LM2917N-8-ND chip instead of relying on the arduino to count and all.

David

 

SgtWookie: I sent you a PM. Do you think we can pick the LM2917N-8 back up?

JimEli: Nothing is written in stone, yet. Hopefully it will be soon, though.

David

 

I'm going to try the 203k and see what i get. I'll post the results )

David

 

203k:
Engine off: 5.01v
Cranking : 4.xxv to 0.3xv
Idle : 0.4x and less

David

 

David

 

Going back to your post on April 9th (bottom of page 6)...

Ok:
235k:
Engine off: 5.02v
Cranking : 1.5v
Idle : .06v

Apparently, 235k is too high. The RUN\ output needs to be 4v or above while the engine is cranking, and below 1v when the engine is running.

194k:
Engine off: 5.02v
Cranking : can not really tell..
Idle : .06v / .11v / .25v / .61v / .44v / .43v....

Try this value again.

Also try 180k.

The higher the value of resistance, the lower the RPM has to be in order to transition the output from high to low.

 

194k:
Engine off: 5.00v
Cranking : 4.00v - ?
Idle : 1.20v - .70v

180k:
Engine off: 5.00v
Cranking : 4.00v - 1.9v
Idle : 1.0v - .40v

David

 

When you are cranking the engine, do you have the ignition or fuel disabled so that the engine won't start? Or are you simply relying on getting a reading during the brief cranking time? (maybe 2 revolutions of the engine)

 

This one:

Or are you simply relying on getting a reading during the brief cranking time?

David

 

I'm afraid that's not going to work very well. You won't have enough time to get an accurate reading.

 

Well if i can find my fuel line power wire then i will disable it and test again.

David

 

There should be a fuse (or circuit breaker) for the fuel pump. Check your manual.

 

David,
How are you supplying the +5v to your test LM2917-8 circuit?
If you're regulating down from an ACCY circuit, be aware that ACCY is normally powered off during cranking/starting.

The same holds true for the BAT (14v) supply of the LM2917-8 itself. I neglected to add a diode and fairly large electrolytic cap (100uF 35v) to keep the IC powered in case the battery voltage dropped substantially during starting.

 

David,
How are you supplying the +5v to your test LM2917-8 circuit?
If you're regulating down from an ACCY circuit, be aware that ACCY is normally powered off during cranking/starting.

The 12v comes off the battery and is converted to 5v using a 12v to 5v regulator (seen in the picture i took a few post back labeled "5v")

The same holds true for the BAT (14v) supply of the LM2917-8 itself. I neglected to add a diode and fairly large electrolytic cap (100uF 35v) to keep the IC powered in case the battery voltage dropped substantially during starting.

Well i have "Radial Electrolytic Capacitors 100 uF 10v 20%" cap's but I'm sure i could not put those in series in order to make 30v? Or could i?

I'm still in the process of finding the cut off switch for the fuel pump.

David

 

The 12v comes off the battery and is converted to 5v using a 12v to 5v regulator (seen in the picture i took a few post back labeled "5v")

Ok.

"a few posts back" turned out to be 9 pages back...

It appears that you do not have any caps on either the input or output of the 7805 regulator. This can cause the regulator to oscillate at frequencies in the MHz range, which will definitely cause problems.

Well i have "Radial Electrolytic Capacitors 100 uF 10v 20%" cap's but I'm sure i could not put those in series in order to make 30v? Or could i?

When I wrote "100uF 35v", 100uF is the capacitance in microfarads, and 35v is the voltage rating. These are available in fairly small radial packages; the E2 package is about 7.5mm in diameter with 2.54mm spacing of the leads.

If you place capacitors in series, you reduce their capacitance. Two 100uF caps in series would have a value of 50uF; three in series would have a value of 33.3uF. So no, placing capacitors in series is not a good idea.

I'm still in the process of finding the cut off switch for the fuel pump.

Don't you have an owner's manual for the vehicle? It should have a chart for the fuse box(es); there should be a fuse and/or a relay for the fuel pump. Removing either would disable the fuel pump.

 

I was referring to this:

which is on page 13.

Don't you have an owner's manual for the vehicle? It should have a chart for the fuse box(es); there should be a fuse and/or a relay for the fuel pump. Removing either would disable the fuel pump.

No owners manual. I'm having to google it and so far have no found a 1990-1992 ranger fuse box diagram in order for me to know which fuse to pull... I'm still searching.

David

 

That looks like you're building a flying trapeze!

Why are you twisting resistors' leads together?

You could use the free area to the left of the LM2917-8's pin 1 to put resistors in series or parallel.

 

That looks like you're building a flying trapeze!

Why are you twisting resistors' leads together?

You could use the free area to the left of the LM2917-8's pin 1 to put resistors in series or parallel.

I twisted them so they would be in series to make 203k.

David

 

No owners manual. I'm having to google it and so far have no found a 1990-1992 ranger fuse box diagram in order for me to know which fuse to pull... I'm still searching.

Why don't you go down to your local auto parts store, and buy a Chilton's or Haynes' repair manual for it? They are not very expensive; less than a tank of fuel for certain.

 

pull some plug leads and it won't start.