Hi all,

I’ve got a bit of a strange issue with my Crossfire and I’m trying to figure out what it could be before I start tearing into things.

The car previously had the known RCM issue with dry solder joints, causing a no crank / no start (fan on etc). That was sorted last year and it’s been running perfectly since, so I thought that was behind me.

On Friday, I was stopped at a red light and the engine suddenly just went quiet and died, no warning at all. When I tried to restart it, there was no crank, but silence from the fan. Hazards still worked so it didn’t seem like a battery issue.

I opened the bonnet and moved the RCM around slightly in its housing (didn’t unplug anything), and after about 15 minutes of trying it eventually started again. I got a brief BAS/ESP light, then it drove fine like nothing happened.

Then today it happened again, but worse. I was coming out of an underground car park, mid turn, and the engine just cut out. Same situation, no crank at all. The fan sometimes came on, no start, but then I moved something and no fan, but still no start. I tried everything for nearly an hour with no luck to get the engine on.

Recovery was already on the way, so before they arrived I tried it one more time and it randomly started. I managed to move the car to a safe spot, and then drove it home with the recovery guy following behind me in case it died again in the middle of the road.

While we were looking at it with the engine running, I showed him RCM and at one point he touched a plug around the left side and the engine suddenly spluttered for a moment, then carried on normally.

There are no fault codes at all, and once the car is running it seems completely fine. Until something like this happens.

So now I’m trying to figure out what this actually points to. Could this be:
- the RCM solder issue coming back
- a connector / pin issue around the RCM
- something like the SKREEM
- a sensor
- or even something mechanical like a valve causing it to cut out

The fact it reacts when something is touched around that area makes me think electrical, but the engine cutting out while already running threw me off a bit as it’s never happened before.

Has anyone had anything similar or can point me in the right direction?

Thanks in advance.

 

Sounds like a bad CPS, crank position sensor. Use Bosch only.

https://www.crossfireforum.org/forum...s-repairs.html

 

I had an issue with the crimp at three pins in the (I believe the 5 wire plug, it was many years ago) at the RCM. I found and had to replace those 90 degree pins inside the plug The metal between the crimp of the connector and where the wire connected, cracked. I believe to this day that the wiring harness was hastily crimped during assembly because the crimps in those connectors were offset and vibration is always present. Of course this happened later on after many start/stop (expansion/contractions of the wiring being heated/cooled, and hot/cold status) of normal operation in various weather.

IF that 'tap' you mention while you and your mechanic was looking to find the problem, was done while it was running, then it in my opinion is not the CPS. Of course, if you take that 5 pin connector apart and see if that connector wiring is good (connector not separated from the wire to the sleeve where it contacts the RCM pins), it may have been one of the other 4 critical plugs, so while your there, I would check the other 4 plugs for the same damage to the plug connectors). The RCM relays do fail (the coils if weak when jarred), also, the contacts of those relays do burn/char and sometime open if vibrated with a weak coil or moderate pitting. Tapping on the plugs of the RCM while it is running will not jar the CPS so I would see if the other steps can produce a result first.

Finally, IF you do troubleshoot the connectors of the CPS, take a few good pictures of the one connector your pulling apart (color of wiring and position) before opening that up (do one connector at a time) and most importantly remove the NEG battery cable since a lot of power may be on those multiple pins (as a precaution). An optical inspection of the relay contacts may show the pitted/burned pins if there, a weak relay electromagnet would be harder to see as there may be observable browning/darkening of the coils wiring that you can see. Good luck! ;;;.


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A bad CPS ( crank position sensor) doesn't cause a no crank issue though

 

When replacing the RCM YOU MUST ONLY PULL ON THE CONNECTORS, not on the wires. Twice now Iv'e seen owners pull on the wires to unplug connectors where they caused intermittent connections in the connectors on the end of the wires.

But also, keep in mind that RCMs are fixable, but they dont always stay fixed.

The easy way out is to put a known-good RCM in and see if that fixes it. I carry a spare RCM, many of us do. Again, the RCM is a KNOWN ISSUE - why do you not have a spare? The no crank implies RCM and the fact you "move things" around the RCM and it starts can imply bad RCM or damage to the connections in the connectors on the RCM wiring.

Replace the RCM with a new one and see what you have, RCMs are cheap, $130 to $180 and are easy to replace - why screw around with what could be a bad RCM? Again, they fail, fixing them is fine, but do not assume a fixed RCM lasts forever, they don't.

 

Yeah, that splutter happened with the engine running. But will have a look at those anyway, thanks.

I’ve always been careful when unplugging the RCM stuff because those wires look old and sensitive, but maybe the previous owner wasn’t or some plugs were loosened from the heat. When I re soldered the pins and refit everything back, I did notice that some plugs were snug to pull and connect back, whereas others slid very easily by comparison.

Crankshaft sensor has not been changed on the car from what I have seen, might be worth to fit a new Bosch one just in case.

Thankful I managed to get it home in one piece so I can actually have a proper look at it myself now. The garages here don’t always seem too familiar with these kinds of issues, and it often ends up being trial and error or wrong things getting taken apart. So I’d rather try and narrow it down first before taking it anywhere again and just fix it myself.

 

QUOTE:

On Friday, I was stopped at a red light and the engine suddenly just went quiet and died, no warning at all. When I tried to restart it, there was no crank, but silence from the fan. Hazards still worked so it didn’t seem like a battery issue.

I opened the bonnet and moved the RCM around slightly in its housing (didn’t unplug anything), and after about 15 minutes of trying it eventually started again. I got a brief BAS/ESP light, then it drove fine like nothing happened.

This is why I suspected the CPS.