JBrown

I have an XDI electromotive ignition system in my car. It has been in the car for 2yrs. Since the day I had it installed I am having a strange issue.
When I shift from 1st to 2nd, sometimes 3rd to 4th the car just turns off. I am not loosing ignition power or fuel. It is the strangest thing. If I run the car hard it never does it . It seems to only happen when I shift in the rpm range of 2800-3500. It does not happen all the time. I can drive the car all day around town and it will happen 1-3 times. I can idle it all day and does not turn off. I can stay in 4th on the highway and it never shuts off. It will also show up if I rev the motor in neutral. Sometimes when it cuts out , it will jump right back up and stay running but most of the time I will have to start it again. I have been playing with this problem forever. I want to fix it once and forall.
These are the fixes I have tried. New cranck sensor, rewired system multiple times. changed grounds. Sent out XDI box and replaced for me. I had a passenger in the car to see if I was loosing power to unit and when it happens the lights on the XDI box stay on and dont change color. The car will start right up, no other issues. The only other parts in the equation is the 3 coil pack and the harness. I was told it could not be the coil pack but I am thinking it has to be that. I have also checked all the pins going into the unit and all connections are good. I have two parts drawing tach signal. I have the tach and a MSD box that operates my soliniod for inrichment. Any exsperts in ignition I would love your advise. Besides that the system is great. I can adjust timing and car runs like a champ with the system.

Thanks for the help
John

m42racer

John,

I have an idea what it could be. Is the Trigger heel small in diameter? I think the ECU is shutting down as it loses count of the teeth as the Cranks "stops" when you change gears. The system does not lose power, nothing to do with Coils or wiring. Fix, would be bigger wheel with bigger teeth. Also check the trigger wheel is tight on whatever turns it. A way to check this would be to use a scope and watch the trigger input pulse coming into the ECU when this happens. If what I think it could be, the signal will lose its pattern.

Hope this helps.

WERK-I

Sorry I don't have a solution, but I do have a friend who has a Ruf 930 that is doing the same thing! They've replaced the crank-sensor and checked the wiring and it's still doing it. He doesn't have an XDi but the earlier HPV-1. I've had a HPV-1 twin-plug for over 10 years and never had that kind of problem.
Have you tried unplugging the MSD box from the XDi to see if it still occurs?

DWalker

A few questions:

What specifically is your trigger setup?

Does this happen with the clutch in or out?

If you are using a trigger wheel or flying magnet setup what is your sensor mounting solution and what specifically is the airgap?

I understand the re-wiring, but can you supply pictures (obviously the more detail the better) of the wiring, especially of the sensor wires.

m42racer

High tooth count trigger wheels need to be big and have big teeth. I expect this to have 60-2 wheel, so if the wheel is small in diameter, then the teeth are very small. Cranks do "stop" and ECU's lose count and reset, (shut down). Just something to look at. As I said earlier, the acid test to these theory is the scope test while running.

JBrown

Hi Guys, Thanks for the info.
m42racer, I dont know what you mean buy the trigger heel. The only thing I can tell you is that I purchased the set up from Clewett and I was under the impression that he gave me the right parts for my aplication. I told them it was for a 930 motor. I am sure I can find out what kind of wheel I have on there.
DWalker, I dont know my tigger set up. It only happens with the cluth in. I know I have adjusted the sensor many times. That has not fixed the problem. I have replaced the sensor and checked the resistance of the sensor and it is within specs. So the sensor is not my problem. At least I dont think that is the problem. I will try to take some pics in the next couple of days.
Yes I did disconnect the msd box to see if it was causing the problem and it still did it with it disconnected.

DWalker

The Clewett pulley is a 60/-2 trigger setup and is a know to work well piece.

My offhand guess is you need to check your airgap/alignment and possibly your crank endplay. Depending on which sensor you have this is an easy thing to check. Using a scope to watch the signal voltage from the crank sensor have someone push in on the clutch and see if thesignal degrades.

m42racer

J Brown,

The scope test is your friend. A few years ago this was an issue in the Focus Midget races. The Electromotive system was spec'ed out as the system that had to be used. The engine would just quit for no reason. The race was lost and as soon as the push truck came it would fire right up and show no reason for the stoppage. It was soon found the ECU shut down as it reset after losing count of the trigger teeth. A bigger wheel with bigger teeth solved the problem. I guess the crank accelerates a small amount as soon as you push in the Clutch.

WERK-I

+1 on the scope. It's an excellent way to check to see if any noise is on the trigger line. Make sure the sheath in the trigger line is well grounded to engine ground. Make sure the spark cables are not close to the trigger feed line. Make sure the chassis of the XDi is grounded to engine ground as well.

Questions:
1.) Does the engine shudder at all before the engine quits? If it does shudder, it may not be the XDi unit at all, but maybe something like an overboost relay (controls fuel pumps) cutting in and out.
2.) Can you provide info on how the DC power is delivered to the XDi? Is it on a relay circuit, spliced off the engine wire harness or wired from the battery through the ignition switch?

JBrown

I will try the scope this weekend.
It is not a fuel pump issue, it shuts right off. It is definetlly not a wireing issue. I have been doing automoble wireing for a living for 27yrs and I went over the wires about 100 times. The car is heavily modifed so there is no overboost relay. I have to take a look to see if the trigger line is close to spark plug wires. I was not aware that could interfer with the pick up senser.
Thanks for all the help guys.

m42racer

I like what D Walker said. Makes alot of sense that the Crank end play would change everytime you change gear. I think he's onto something.

Good luck.

DWalker

I have had just about every cranksensor issue you could possibly have with a mag or hall type sensor. There is so much that matters- heat, cold, engine speed, airgap, alignment, and the list goes on. Pictures of the installation, wiring, etc. would help me help you.

don

JBrown

I will try to take some pics today.

JBrown

here are some pics of the crank and crank sensor and how I have the wire routed. If you are wondering what is under the crank sensor mount. It is a piece of extreme dynamat. I had a small hole and I wanted to seal it. I had the problem before I put that there. Thanks John

WERK-I

What air gap are you running between the sensor and the trigger wheel?
Should be: 0.030 to 0.035 (0.9 mm).
The locking screw should be lightly tightened to 45 in/lb.

Do not over tighten, this can lead to internal windings shorting out.

That is the same sensor, sensor clamp and trigger wheel I have on my car. Never been a problem. The smaller earlier sensors were problematic.