PS2000 Miss Counts When Warm
 

Finally got an FD project car up and running after a few years of building and am having trigger miss counts that I cannot seem to figure out. The problem we run into (with two different PS2000 ecus) is that it gets real bad trigger miss counts when it is fully warmed up after driving a few miles. If I swap ecus they it will be okay for a short bit and the problem comes back. The triggers since last home wander between 11 and 13 when it is acting up which leads me to believe that it's a trigger VR signal miss and not a home VR miss.

-factory FD VR sensors
-850 primary injectors, 1600 blue top secondaries. I assume high imp pri and low imp sec
-haltech power is pulled straight from alternator lug
-haltech harness grounds to top of engine block
-LS2 coils (w/ heatsink) w/ signal ground wires to lug on frame rail and power ground to haltech harness
-VR sensor wires are not mixed up (NE + ecu pin 1, NE - ecu pin 5, G+ ecu pin 2, G- ecu pin 6)

Looking for any input on the miss counts. Car runs awesome until miss counts occur when warm.

- ECU signal ground, large B/W wire, needs to go to battery negative.
- Positive wires need to go to battery positive.
- Power ground, large black wire, needs to go to a good clean chassis ground.
- Coil pin B can connect to ECU signal ground or the engine.
- Coil pin A must connect to the engine. Do not connect it to ECU signal ground or gang it with ECU power ground on the same lug.
The way you have it wired is asking for noise to be introduced. The battery acts as a capacitor and dampens voltage spikes. Wiring directly to the alternator is a terrible idea.

Sounds like it's not missing a home or trigger count. Trigger since last home is supposed to be 12 at all times but you're getting 11/13. So it's seeing all the teeth, it's just seeing them out of synch. My guess, even though you state otherwise, is that you have one or both connectors wired backward and you're triggering on the wrong edge allowing the trigger point to move.

Or you have selected rising edge for the trigger and/or home edges.

Trigger settings:
Attachment 562954

Short log of wandering triggers since last home:
Attachment 562955

You are right, it doesn't appear to be missing the trigger/home counts, it like the home signal keeps flipping out of sync. I will address/redo the power and ground sources then give it another go.

Just an update of where I am at.

- I have rewired the power and signal ground directly to the battery terminals
- Coil pin B is tied into the signal ground circuit in the harness
- Coil pin A is grounded to the chassis near the left strut tower (this is where it was previously)
- Power ground is attached to a lug on the top of the motor
- Existing braided ground strap still present from UIM bolt to right strut tower
- Existing negative battery cable present from center iron to left strut tower

I had to switch the trigger offset to 9 from 10 now in order to get it back where timing belongs. The trigger/home sync issue is still the same however. Sourcing a known good set of VR sensors to try next.

An odd thing to note is that when the throttle is held at 100% to perform a flood clear, the miss count goes away and it's a perfect TSLH 12 every time. When throttle is returned and injectors fire again, the miss counts return. Is it possible that the coils are back feeding during mis-fire and screwing the ecu up?

Thit is what I referenced for the VR pin outs. Are the + and - pin outs on the VR sensors correct on the following diagram?

EDIT: For future reference, the following image is incorrect. The VR + and- wires are backwards in the following diagram!!

https://cimg7.ibsrv.net/gimg/www.rx7...b3bb6637a1.jpg

On the FD trigger tooth offset is 10 every time, no exceptions. I'll check the diagram when I get home but the fact that you have to enter a tooth offset of 9 to synch the timing screams to me "wired sensor backward".

That diagram is wrong. I just pulled my notes through my phone. Swap the terminals at both sensors, set tooth offset at 10, and trigger angle at 65 and you'll be good.

Then the first post in this section is wrong, no?

I see the link at the top of that same thread and it has the + and - backwards from the other image that I found on rx7club.
PS1K to FD w/ LS1 coils

I don't know what is posted elsewhere. I'm telling you, the image you just posted is wrong. Also, what you just quoted from Claudio is wrong. Swap the terminals and set the tooth offset at 10 and start with the trigger angle at 65. Adjust the trigger angle to zero the timing. Shouldn't need to change it by more than a degree or two.

Right. Not disagreeing with you at all. Just stating what lead up to where I am at now.

Got the wire swapped and it fired right up, but had to shut down immediately due to a fine mist of gas coming from a dry rotted push-lock hose which was new when the project was first started.

Fixed. This is after 45 minutes of driving too. :icon_tup:
https://cimg4.ibsrv.net/gimg/www.rx7...9ca15f0130.jpg

Now, buy your stuff from me next time. ;)

Sticker on the back of the ecu says lms-efi.com. ;)

Harness was assembled elsewhere.

:)

Congratulation Ldwig...You understand very well miss fire on Rotary engine using Haltech...