yet another 4300 rpom post

[ion332]

OH well thats cool!

I put a huge cap on my coilpack and no change.

I even switched to a 6-1 wheel and now I got no start! This is insane.

I seriously thing that my vb921s gotta come outta there. UGH this stinks.

[ion332]

Car runs with the 6-1, ended up wrong tooth removed, so I re-indexed it.

But, I lost throttle response and still don't know why the 36-1 wheel didn't work.

It works now though, YAY!

[Keithg]

did you try both wheel decoder types?

KeithG

[ion332]

did you try both wheel decoder types?

KeithG

Yes. If you mean 24s9 and the 25, yes I tried those just to see, both seemed to work fine.

As far as the wheel itself:

The 36-1 wheel works great, startup is quick, idles very smoothly, throttle response is monstrous but it won't rev past 4300rpms. Tried everything except a new VR circuit (currently using LM1815)

The 6-1 wheel works decently, idle is a bit more rough, throttle response is acceptable, and will rev out to as far as I want to go. (once again, lm1815)

I think the LM1815 just isn't up to the job imho. I am going to either go with the very simple 8-pin ON semi dual VR conditioner or build the v3.0 conditioner and try again soon.

[Fastest95PGT]

I think the LM1815 just isn't up to the job imho. I am going to either go with the very simple 8-pin ON semi dual VR conditioner or build the v3.0 conditioner and try again soon.

Are you running all the suggested capacitors in the following diagram?



I believe at least one (bottom right one comes to mind) needs to be changed based on the max number of triggers so the circuit doesn't get overwhelmed.

[ion332]

I think the LM1815 just isn't up to the job imho. I am going to either go with the very simple 8-pin ON semi dual VR conditioner or build the v3.0 conditioner and try again soon.

Are you running all the suggested capacitors in the following diagram?



I believe at least one (bottom right one comes to mind) needs to be changed based on the max number of triggers so the circuit doesn't get overwhelmed.

Yes, they are all there.

Its an RC time constant, so, it would prlly be easier to adjust R to speed up the charging of C.

Max Fin= 1 divided by (1.346 x R x C)

So, you can see as the value of R or C decreases, max Fin increases. I did think about just going overboard and just putting in a 330pf or something in there just to see what it does.. But at one point I put it to Vcc and thats suppposed to disable the one shot and it still didnt help. Still ran well until that point though.

BTW, that divided by is there because some stupid quickkey BS! I hate that stuff man o man takes hours to figure out what program is screwing things up on you! Divide by rant mode off.. Anyway!

Nonetheless, I went through all the datasheets and we came to the conclusion that it SHOULD work, HOWEVER, I used to work for a subsidiary of ST looong ago and we spent thousands of dollars to redesign around many of their datasheet errata.

I am going with the ON semi dual VR next, its only 8 pins, very easy to setup and its specifically for automotive apps.

[Fastest95PGT]

Sorry, by running all the suggested components, I didn't mean the count. I meant the values.

Such as the bottom right cap.. is it .001uF on your circuit?.. or perhaps .01uF instead?

[ion332]

Sorry, by running all the suggested components, I didn't mean the count. I meant the values.

Such as the bottom right cap.. is it .001uF on your circuit?.. or perhaps .01uF instead?

yeah lol..

Fin max = 1/(1.346 x R x C)

Fin max = 1/(1.346 x 50E3 x .001E-6)

Fin max = 1/67.3E-6

Fin max = aprox. 15kHz

my theoretical max input frequency is:

Fin wheel = number of teeth x max rpm x 1/sec
Fin wheel = 36 x 9000 x 1/60
Fin wheel = 5.4kHz

So, unless STs datasheets absolutely SUCK and are WRONG, the Fin max is 3 times that of my real input max rpm.

Thats for the RC timing pin 14 for the integrated one shot: if R/C are too large, the one shot pw will be so wide as to overlap and rail the input to the cpu, at which time you get spark cut and sync loss.

And thats what I proposed was to change the .001 uF to a 330pf, but, I eliminated it altogether by connecting pin 14 to Vcc. That gives is a theoretically infinite input freq maximum.

[sportage4x4]

do you have a part number on that dual vr ic from on semi?

[Fastest95PGT]

I didn't follow your other thread (or even open it) but does this issue only happen under boost?

I'm curious if you can reproduce it in neutral in which case how about scoping the VR and the output of the LM1815 circuit to compare the results?

[ion332]

I didn't follow your other thread (or even open it) but does this issue only happen under boost?

I'm curious if you can reproduce it in neutral in which case how about scoping the VR and the output of the LM1815 circuit to compare the results?

I am too lazy and tired right now and I got a torque converter in my truck to fix so that will be a little bit.

What I *can* do is set-up a test fixture and take the other POS oops, I mean nifty lm1815 and opto and breadboard the same circuit.

I sorta wondered if the opto circuit may be running past its limit also ala c11 needing to be reduced or removed.

[ion332]

do you have a part number on that dual vr ic from on semi?

http://www.onsemi.com/PowerSolutions...clearFilters=Y

NCV1124 Dual VR conditioner.

Its only got 8 pins.. VERY simple to set up, and VERY cheap.

Also, its VERY smt, so, best bet is to turn it upside down, glue it down, then solder wirewrap or 20g wires to the legs directly.

SMT or no, if it works its still a godsend if it works as well as they are saying.

[sportage4x4]

yeah looks very nice, designed specifically for automotive apps like crank/cam sensing, thanks.

[Fastest95PGT]

http://www.onsemi.com/PowerSolutions...clearFilters=Y

NCV1124 Dual VR conditioner.

What did you use for cap and resistor values?

[jsmcortina]

I think the LM1815 just isn't up to the job imho. I am going to either go with the very simple 8-pin ON semi dual VR conditioner or build the v3.0 conditioner and try again soon.

I am using the LM1815 on a 36-1 wheel and have seen 6700rpm

James

[renns]

NCV1124 Dual VR conditioner.

Its only got 8 pins.. VERY simple to set up, and VERY cheap.

Also, its VERY smt, so, best bet is to turn it upside down, glue it down, then solder wirewrap or 20g wires to the legs directly.

SMT or no, if it works its still a godsend if it works as well as they are saying.

Looks like a nice 2-channel conditioner, but does it provide true zero-crossing detection? If it really does the job properly, then it'd be a great choice to replace those two LM1815's.

Roger.

[ion332]

I think the LM1815 just isn't up to the job imho. I am going to either go with the very simple 8-pin ON semi dual VR conditioner or build the v3.0 conditioner and try again soon.

I am using the LM1815 on a 36-1 wheel and have seen 6700rpm

James

Yes, but, you cannot deny that at one point you did have a somewhat inexplicable problem and had to change the airgap to get the rpms back up. How is that the EDIS controller was able to work just fine on my car with the same sensor, wheel, and airgap and yet the LM1815 cannot? What is electrically different that causes it?

I don't really have the option to change the airgap, the sensor needs to be mounted in the oilpump housing.

I guess what I am saying is not that it *wouldn't* work, but moreso what needs to change electrically to *allow* it to work in all conditions? Is it a problem in the circuit between the lm1815 and the CPU?

[jsmcortina]

I am using the LM1815 on a 36-1 wheel and have seen 6700rpm
James

Yes, but, you cannot deny that at one point you did have a somewhat inexplicable problem and had to change the airgap to get the rpms back up.

Spark plugs covered in oil.

James