ECU or not ECU!
 

Hello All

Sorry to start my first post with a call for help or advice, but after 30 years and 270000 odd miles, my 240 Estate has decided to break down and I suspect it’s the ECU unit.

It was running OK until just before Christmas when one morning it started OK, ran for a minute or two, spluttered and has since refused to start!

It’s had a new main fuel pump, new fuel pressure regulator etc. and had a local Auto Technician go over it announcing that it was fine - it just won’t start. He thinks it’s off fuel, but back at Christmas it wasn’t off!

The ECU in question is a Bosch 0 280 000 951. I’ve read various posts on the forum about repairing your own ECUs but I’d rather just buy a replacement as after that mileage it’s not done bad!
I read a post mentioning a Rod Westbury, but the link doesn’t seem to work, and I’ve read many posts by Classicswede and visited his webshop, but really I’d just like the ECU repaired/rebuilt rather than updating the whole system.

If anyone could recommend a good rebuilder of ECUs that would be great, or does anyone have a rebuilt one for sale?

Sorry to start on an ask!

Many thanks. Roger

Welcome to the forum

The ECU's aren't a common failure point in these so I would be surprised if it was the issue.

What year/engine is your car?

What are the exact symptoms other than it won't start? Does it have spark? Does it have fuel?

The crank position sensor (if your car is LH2.4) on the back of the engine above the bellhousing is a common failure point, if the ECU gets no signal from this then it doesn't give the coil power to produce a spark. An easy test is to take the king lead off the distributor and put a spark plug in it, rest the plug on the engine block and see if it sparks, if it doesn't then chances are you've got a dead £30 crank sensor (use Bosch or NGK for replacement).

It is very rare for a ECU to fail

Most common faults
Poor contact on fuel pump fuse
fuel pump relay
crank sensor
ignition amplifier


1st two tests are always 1- do you have spark? 2- do you have fuel to the fuel rail? Once you have answers to both of those questions you can move forward

I absolutely agree with classicswede. I've had each of his four main faults, once, over some forty years and owning four 240s, each easy to diagnose and very cheap to fix.
Just in case I carry a spare fuel pump relay, crank position sensor and an ignition amplifier module ready-bolted to a heat sink. I must have covered about 800,000 miles in total, with never an ECU fault.

Thanks for the replies!
 

Thank you all for getting back to me. The car is a 1993 240 Estate 2.3, on the timing belt cover it has 6821080. B230F. NR 615.

I've checked the fuses several times. It's got two new fuel pump relays one fitted, new ignition amplifier and the crank sensor is only a couple of years old.

I even got a local Auto Electrician round as well, we have spark, we have fuel and in his words it should start!

He left me to get a new fuel pressure regulator, which I've fitted over Easter, but still no start. As you turn the key you can hear the fuel pump start and it pressurises the system, then at best it cranks over, stutters and then fails to fire!

The only things left I can think of is the fact that the fuel gauge gave up the ghost last summer, which was going to be my next job, but as the top of the tank looked rather iffy to me I was going to do it later once I'd got one of my other non running vehicles out of my garage!

But I can't really see why the fuel gauge would cause a no start .... yes it does have fuel!

My Auto Electrician left me saying he thought it was just bad fuel as I'd recently filled up at my local Tesco's but I've never really heard of that before.

So as you can see I'm a little lost!

One last question I haven't tried to jump the fuses between 4 and 6, mainly because my fuse 6 doesn't have a wire coming of it, and I think I'd read somewhere that right at the end of production Volvo left fuse 6 more or less redundant.

All the best, Rog

If you have fuel and you have spark then it should run.

What has likely happened is that the cam belt has jumped or the crank sproket has sheared its location lug causing the timing to drift.

A compression test would be the next step, if teh timing is out teh compression should have dropped.


The other possible is the maf has died. You can try unplugging that and then try and start. This is the least likely but a very quick one to test

Well I never knew 240's had that little trick!
I'll have a closer look at the weekend as I'm living in a building site at the moment, plus a word with a local mechanic to see if he can fit me in.
If that's the problem I can change the slightly weeping top oil seal as it's been sitting in the glovebox for the last few years waiting for me to change it!

I'll keep you posted and many thanks for the help. Rog.

If your cam seal is leaking then your six seal and front crank seal probably are too and your PCV system of you haven't done so already would benefit from a decent clear out, good look with your car :)

would agree to check the timing. mine has jumped its timing twice over the years and both times has either not started or ran then died. its not too much of a job to re time it, as long as it hasnt hit valves

Stupid autocorrect, that should have said aux seal not six seal and good luck not look.

I'd definitely check compression if you have fuel and spark.