Hi we have a Mitzi Carisma. GDI 1999.. Circa 29 K Miles.
It runs great once it is started. But if it fires up and we switch it off, It just wont fire up again for a while. Then it will fire up again and all is ok runs smooth. No problem at all while running. It never cuts out on the road. Only problem is after switch off it wont immediately fire up again. It will turn over good. We have 2 immobiliser type keys, its the same on either.
Battery seems fine. Spark at plug leads while its cranking but not firing.
The only way to do this though ,is to let a garage plug in the tester then take a read out .My guess it will say :: .immob communication.:: That will entail an new immobiliser cpu (central processer unit ) and recoding of the keys. Jonny
I thought about that as the problem. But I talked to Mitzi engineers today. If the Immobiliser was faulty we would get no spark at the plugs while we were cranking We get a REAL HEALTHY Spark.
I'm not familiar with this vehicle, but If you are getting spark, it only leaves two other components: fuel, and compression. Try spraying some starting fluid (ether) down the air intake and if it fires you can assume you are not getting fuel which could be a filter, fuel line problem, fuel pump, or shut down relay. If this does nothing, then look for a broken timing belt or some other physical problem preventing compression.
Since the engine does run, the belt is OK. I'd start by looking at the fuel delivery system. Either the pump is not starting (could be the MPI relay behind the radio or on the RHS A-pillar) or the injectors are not being fired (ECU issue, perhaps the infamous leaking electrolytic caps). Does the Carisma have an injector resistor block (4 x10W ceramics in an aluminiium cage) on the firewall? 4G63 turbos have these, most others I have seen don't. If the injectors are not getting +12V, the ECU can't fire them (by grounding each in turn).
Could also be the coolant temp sensor connection. This makes for a hard start if the connections are poor.
My assumption here was that if the timing belt slipped a couple teeth it could be enough to prevent starting, but not enough to disable the spark control. This was strictly an assumption on my part since I agree with you that if the belt broke away completely and if the vehicle is equipped with a cam position sensor it would report an error, set an engine code, and disable the ignition control.
If this thinking is not correct, then let me know where I erred so that I can learn from this exchange.
By the way, I agree it is more likely a fuel delivery issue and that is why I suggested the quick test using the starting fluid...
Well we got a little further today, but rain stopped play kind of thing.
It is the injectors not getting energised. We made up a LED indicator panel. Lifted the supply to one of the injectors. Turned Ignition key. It fired on 3 ok and we could see the 4th was getting drive because the LED was lighting.
When we were cranking and it was not firing there was no drive to the LED indicator.
By the way we have never had a fault light show ever on the dash.
We dropped into local Mitzi dealer. £55.00 plus VAT to look at computer diagnostic tester.
Not a lot of help otherwise. More just sharp intake of breath and £ signs in each eye. They had no idea. So I said once we found it we would only charge the £55 and no Vat to know lol.
Never mind we are nearer.
I would have thought it was early for electrolytics to dry out. But thanks for tip. Both my son and I are into electronics He computing Me medical scanners etc
Original poster states "It runs great once it is started", hence the belt has not slipped. If it does jump a couple of teeth, assuming it does not bend valves, it will obviously run very poorly. Case in point, the 4G64 SOHC in my 93 Expo jumped a couple of teeth, and while it would start, it ran like a dog, pinged like mad and would not rev over 2500. I reset it and two days later it did it again. Inspection showed oil contamination from an external source. A new belt solved the problem.
Ah, a cricket metaphor ... not surprising since you are in the UK. Last time I played cricket was in the Australian Army 34 years ago, us (RAAC) against them (RAEME). I was out for a duck, first ball through the center stump. They didn't ask me to play again. But I digress...
You'll probably need a wiring diagram for the Carisma to sort this out, as I suspect its a bad connection somewhere. Tell me the engine type (see the center firewall plate): its one of 4G15, 4G93, 4G63 and 4G64, or perhaps
4G94.
Based on what I know of the 4G15, 4G93, 4G63 and 4G64 engine electronics, when the starter cranks, the MPI relay drives the fuel pump, and the cam sensor sends a signal to the ECU that its time to drive the injectors. The MPI relay also switches power to the ECU. As far as I can see, the injectors should be driven while the engine is cranking. I don't know about the Carisma, but the 4G63/4 IGN Start through the MPI relay drives the fuel pump too. 4G15 does not.
Locate the MPI relay. Is there a click or clicks here when you crank? R/R the connectors adding a squirt of WD40. You can, for diagnostic purposes, jumper the MPI relay to supply power to the fuel pump and the ECU.
Pull out the ECU, and check the caps. You could first just try R/R+WD40 the three harness-ECU connectors a few times to ensure good connections. Its happened a couple of times here when the weather was damp. It would be diagnostic to put your LED on the injector drive pins.
I'd also check continuity of each injector sink wire to the ECU. The injector power supply wire (+12v or +100v apparently from another poster) should be common to all injector connectors.
As to the £55.00 plus VAT to look at computer diagnostic tester ... If the dealer had no idea, why would they expect you to pay. Did their computer indicate anything related to the immobilizer?
Here in Canada, if a dealer said they could diagnose a fault with a computer, then afterwards tells me they had no idea, I'd be pretty unwilling to pay for a service not rendered. Perhaps customs are different in the UK.
Just read your problem 5 mins ago, thought i could help. In reference to the message from stewart he mentioned the injector block. this is infact the drive unit for the injectors and has four capacitors which gives you the high voltage that johnny mentioned. This is where your problem lies..... On this and with any direct injection engine petrol or diesel you need high pressures to inject fuel.On the GDI you only need high voltage at start up hence the 100v then when running the voltage drops to a more suitable voltage.If you open up the drive unit and check the solder joints you will find one or two capacitors loose.. good luck.
Helpful comment. I wasn't aware that newer engines had the capacitor discharge injector system.
I guess its about time I got some 99+ manuals and updated my knowledge with the recent systems. My cars are both 93's, and the Summit GTX has the rebuilt 91 Eclipse 4G63T.
Gentlemen, What a wonderful response to my HEP!!!!!!!!!!!!!!!!!! The car is not available for me to look at until Monday. Son is at GFs and its his car.
But I thank you for the suggestions. I will of course report back with our findings.
We have managed to download a manual from the Net that seems to cover most things its just a matter of wadeing thru it.
You say the MPI relay...What does MPI stand for ?.
But its kind of interesting. Who ever said life should be easy and without problems. I am pleased my son and I have the experience to check most things out. I fear costs if it was just drove into a dealers.
In passing I had a phone call from my son last night to say he had run around in the car ALL day and it had never failed to fire up on first turn of the key. ???????????????.
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