A reluctant Starter - Now Sorted by S & C

[Jonathan Kay]

Can you connect a voltmeter between one of the terminals on the intertia switch (either one if you can do it without disconnecting) and earth and see what it shows when cranking? It should read zero when the engine is stopped, something like battery voltage when it's running ... But I'd be interested to know what when it is cranking but refusing to start. Basically, is the ECU powering the fuel pump when cranking or not.

Just catching up... have you also measured the minimum voltage while cranking across the battery and at the fuel pump?

Jonathan

[Piers300]

Jonathan. I fitted a brand new battery a couple of weeks ago. When being serviced, they checked fuel pressure at the rail and it was around 3.5 bar. We are reasonably sure it is not the in tank pump and more likely to be a wiring fault or an ECU fault. Everything else has been replaced.. I have to admit that I am beginning to loose patience with the car and have even thought of getting rid of it.

I now have a connection to the engine ECU and need to get myself the cable and software to view what is happening when cranking. The car still starts and runs fine when fuel is squirted into the T/B's. It will start when hot sometimes, but not from cold.

 

Piers

 

 

[Paul Deslandes]

Piers

It's really disappointing that you're not getting anywhere with this.

Apart from the engine just needing enriched fuel to start when cold, another possibility is that the fuel line pressure is not building sufficiently to feed the injectors during the initial two seconds that the ECU powers up the pump.  When the fuel pressure was measured as 3.5 bar, was the engine actually running or just ignition-on?  If the latter then my suggestion won't work as the pressure is correct prior to cranking, but if the former then it might.

Earlier it was suggested that repeated turning on and off of the ignition every couple of seconds, say 5 to 10 times, would allow the pressure to build and it was worth trying this to see if it made any difference.  I wonder if you tried this.  This might work if the fuel is being allowed to bleed back to the tank from the fuel rail, partially emptying it over time once the pump is switched off.   This is similar to the situation after reassembling the fuel rail and injectors and there's no fuel in the rail.

Unfortunately I don't see how using Easimap to read the ECU is going to show what's going on as there's nothing for the ECU/software to sense.  It would however allow the cranking fuel enrichment to be increased, either directly or by spoofing using the coolant temperature fuel map settings if it proves necessary.

Pity you're not a bit nearer to Guildford.

Don't give up

Paul

[Piers300]

Paul

I understand the fuel pressure was checked with the ignition on and the engine not running.

i have tried switching the ignition off and on quite a few times and no difference.

i have checked the voltage at each injector when cranking and it was about 6.4 volts.

The connection to the ECU was done by Arnie Webb and I have no experience operating this system or making adjustments. Arnie is on holiday at the moment so I am not in contact with him till he gets back, so I am having to be patient.

 

Piers

 

[Paul Deslandes]

Piers

well that rules out that theory then, leaving us with the probability that it needs some enrichment when cold.

Did Arnie by any chance leave you with a .ec2 file,copied from the ECU to Easimap?  It would be interesting to have a look 'off-line' to see what the maps look like and whether the cold start fuelling can be tweaked.

One thing that can be read from Easimap when it's cranking/running is the injector duty cycle, which gives an indication of the level of fuel being commanded by the ECU, if not actually delivered.

Paul
 

[Piers300]

Paul

I just spoke to Craig at SBD Motorsport (agents for MBE) who was very helpful. He asked if the injectors have been tested and they have not. They can test the injectors and re-build/clean them and can also test the ECU if no problems found with the injectors.

No, Arnie did not leave any files as I have no laptop to put it onto. I do have an old work laptop out in the garage and I was going to see it that still works. What do I need to run Easimap?

 

I am quite tempted to just get this done by SBD.

 

Piers

 

 

 

 

 

[Paul Deslandes]

Piers

I know Craig and SBD very well (Arnie is not an SBD fan!!).  They have an ASNU machine which will test and clean your injectors and they'll rebuild them with new filters etc.  I would honestly doubt that you have a fault with the ECU, other than the map.  Otherwise the engine wouldn't run properly once it's warmed up.

The old 967 ECU is very fussy about the pc that you use to run Easimap.  It needs an integral serial port, not USB to serial adapter, and to be running Windows XP and the older Easimap 5, which can be downloaded from the SBD website. 

The serial cable to connect the ECU to the pc is not a standard RS232 cable and using the wrong one will very likely damage the ECU or pc or both..  SBD will sell you a cable but they are very expensive (~£80) so you can either make your own from the instructions on their website for about £10 or borrow one.  If you do decide to make your own cable, ignore the resistors as they're not needed so you can leave them out.

Running Easimap with the ECU would enable you to see whether the temperature senders are giving sensible readings on the ECU and to look at the maps and see what can be tweaked.

Paul.

[Piers300]

Paul.

ECU and injectors sent to SBD for testing. The injectors (0280 155 868) will have new seals and filters fitted and will be cleaned. Let's hope they give more fuel on cold start.

Are these injectors used on the R300, R400 and R500?

Piers

[Paul Deslandes]

Piers

I'm afraid I don't know where those injectors are fitted but I'm sure someone else will

Paul

[Piers300]

Update

The injectors and ECU have been tested by SBD and all are working fine. 

The only things not changed are:  The TPS and the in-tank fuel pump.

The TPS looked good when connected to the software and was doing what it should.

The fuel pump is a bit on an unknown.

Steve at SBD suggests that the problem may be a duff starter motor. He says that if the cranking speed is irregular, the the ECU is re-setting itself all the time and does not give the engine a spark. Does this sound possible ?  It has a new battery fitted and seems to crank well.

 

Piers

.

[Jonathan Kay]

He says that if the cranking speed is irregular, the the ECU is re-setting itself all the time and does not give the engine a spark. Does this sound possible ?  It has a new battery fitted and seems to crank well.

I haven't heard that specifically but it's very close to the known problem of the voltage drop during cranking causing problems for the ECU.

Has anyone suggested measuring the battery and fuel pump voltage during cranking? ;-)

Hope you're sorted soon.

Jonathan

[Jonathan Kay]

PS: What sort of starter?

Jonathan

[Piers300]

Jonathan. I don't know and assume it is what was fitted as standard.

 

Piers

[Piers300]

Just done a search on starter motors and there seems to be issues with the Brise causing the volts to drop to 5.2 volts. Revilla did the evaluation and shows the graphs from an oscilloscope. This was causing the ECU all sorts of problems.

i need to find out what starter motor I have. Can anyone advise what starter was fitted as standard by Caterham in 2004 on an R300

Thank you​

 

Piers

 

 

[SM25T]

My late 2002 car has a Magneto from a Skoda. Can you take a photo of it ?

[elie boone]

it wouldn't harm if you take it apart, clean and grease it.

[Jonathan Kay]

Just done a search on starter motors and there seems to be issues with the Brise causing the volts to drop to 5.2 volts. Revilla did the evaluation and shows the graphs from an oscilloscope. This was causing the ECU all sorts of problems.

That's why I asked. The drop was too transient to show on an ordinary meter. But I'd still recommend doing that test anyway.

It later appeared that the same design of starter was sold under other brand names.

Jonathan

[John Vine]

Just done a search on starter motors and there seems to be issues with the Brise causing the volts to drop to 5.2 volts. Revilla did the evaluation and shows the graphs from an oscilloscope. This was causing the ECU all sorts of problems.

Linky.

JV

[John Vine]

He says that if the cranking speed is irregular, the the ECU is re-setting itself all the time and does not give the engine a spark. Does this sound possible ?

I couldn't say, but even if it's possible, it doesn't seem to fit with your earlier report that you can start the car by squirting fuel into the RBs.  To me, that suggests the ignition is working OK during cranking, and that the problem is simply (if only!) one of inadequate fuelling.

Andrew's investigations relate to a Rover MEMS ECU.  Would an MBE 967 misbehave in the same way when supplied with too low a voltage during initial cranking?  If so, would both ignition and fuelling be affected adversely?  If yes, I can't see how your starter is to blame.  (But am ready to be proved wrong!)

JV

 

[Paul Deslandes]

I agree with JV that it's unlikely, although not impossible, that the ECU would fire the plugs and not the injectors. The same would apply to Steve at SBD's thought re the ECU resetting.  If that were the case it still wouldn't start when you inject fuel by hand.

At risk I know of sounding like a stuck record, get the ECU hooked up to Easimap and see if the cranking fuelling can be increased.

Paul

[ECR]

Would successful push starts eliminate/confirm the starter motor ?

[revilla]

i have checked the voltage at each injector when cranking and it was about 6.4 volts

What exactly were you measuring? The voltage across the two pins of one injector? Or the voltage between one of the injector pins and ground? If the latter, which pin (which coloured wire)?

Has anyone suggested measuring the battery and fuel pump voltage during cranking? ;-)

At risk I know of sounding like a stuck record, get the ECU hooked up to Easimap

These are the two most important things you really must do next. At the moment you're just trying to make educated guesses from symptoms. You need data on what is actually happening internally. You need to know how the power supply system is coping, what the ECU is seeing from its sensors and what the ECU is doing. I don't know how much diagnostic info the MBE gives you but you may find that the ECU is well aware of the problem as trying to tell you, but until you connect up to it you're not listening.

Long shot ... maybe the voltage is dropping during cranking and the MBE is coping (I've no idea how low a voltage they will tolerate) so continuing to fire the ignition, but the reduced voltage isn't allowing it to drive enough current to the injectors to open them, or at least causing them to open sluggishly.

[John Vine]

Arnie Webb very kindly came over to my house on Saturday. He said the first thing that needed doing was to install the RS232 cable into the ECU, as without it, we were in the dark to what was going on.

He's quite right, of course.  Is he back from his hols yet?  Would he be willing to look into the ECU again for you?

And (turn cracked record mode ON), have you consulted CC?

JV

[aerobod - near CYYC]

With Easimap and CAN based MBE ECUs (992, 9A4), the sample time for data points is 50 milliseconds or better, so it is easy to see battery voltage drops during cranking. I don't know what the sample rate is on the 967 ECU, but it should be at least 10 times per second, enough to show a voltage drop issue. The ECU reset count in Easimap will also increment if the voltage drops too low.

[Jonathan Kay]

Is it obvious from the display if the whole ECU goes down for a short time because of loss of power? 

Jonathan