Standard MBE ECU for HPC on carbs

[IanWatson]

Hi all,

 

My 1992 HPC has recently picked up an irritating ignition fault. Now there is no spark at all.

 

I've got a pal who is very competent autoelectrician - he's tested ALL the related wiring and connections for continuity (including immob, rev counter, battery cut-off). He's also fitted new dizzy cap and arm, replacement crank sensor, new plugs and leads and a new set of spark plugs.

 

After all this, the coil is getting 12v but still no spark. My friend is pretty certain it's either the coil/amp or the ECU.

 

The coil is a cylindrical type, with what looks like an ignition amp mounted underneath on a heatsink. The ECU is a small black unit with no serial number marked on it.

 

I'm told this ECU is likely to be a 906.

 

So rather than replace both, I'd like to try a known-good ecu and coilpack. I'm based near Barnet in London.

 

Can anyone help me with this before the summer ends? Can't believe my second summer with this car has seen it sat on the driveway.

 

many thanks

Ian

 

1992 HPC on 45s

205 GTI Mi16

[IanWatson]

Just to shed a little more light...

 

A few piccies of the offending items here

 

Any assistance will be a summer-saver

[andy_h]

Ian,

I may be able to help you. I've a spare which MBE themselves confirmed via email;

 

---------------------------------------------------------------------------------

It's a 900 series ECM. Built January 1991!

 

It was fitted as standard to Caterham's it was designed to run with the

standard crank trigger wheel & sensor, distributor & coil amp. 7k5 rev

limit.

---------------------------------------------------------------------------------

 

Send me a blatmail with your email address to discuss further.

 

Cheers,

Andy

 

 

White road legal 2.0 HPC VX race car - Now all shiney and new 😬

[andy_h]

feck ... just wrote a long reply to help and the web page lost it when I pressed the post button *mad*

 

Short answer...

Check the wiring on the back of your master FIA switch first.

 

I had no spark on mine and found to be FIA switch knackered internally. My master FIA switch also controls the spark via the MBE.

 

Test yours by shorting the "correct" small wires on the rear of the FIA switch when the switch is in the on position.

 

Cheers,

Andy

 

 

 

White road legal 2.0 HPC VX race car - Now all shiney and new 😬

[IanWatson]

Hi Andy

 

Thanks for your offer - a Blatmail will be with you soon.

 

In terms of the FIA switch, my pal has checked and double checked the switch in his process of elimination.

[k.russell]

Ian, i think if you search the archives there is a bit about the fallibility of these ECU's. unfortunately i sold mine when i went to injection or you could have had mine.seem to remember it was discussed at the time in depth and i may have sold it to one of the guys with similar problems to yours. good luck i hope you get sorted swiftly.

 

Kevin R

 

black(but sometimes orange)-ali HPC

here

[Paul Deslandes]

Ian, you obviously want to get the car going asap so that you can enjoy the summer but if you find that you're going to have to spend some money to get it fixed, you might want to consider going for 3D mapped ignition. It involves the addition of a throttle position sensor, a suitable ECU and a bit of wiring but it hugely improves the driving experience in terms of pick-up, economy and driveability. A number of HPC guys have done this and would never look back.

 

Paul

 

 

[jonboylaw]

Megajolt it!

 

Jonathan

=========================

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92 Supersprint, Ford LSD LA, RK AX Crossflow. Stealth model (Matt Black and Ali), rebuild completed.

 

[IanWatson]

Without doubt the sensible thing would be to upgrade the ignition management at the very least.

 

In fact I'm fairly sure I'd see at least a 50% improvement in fuel efficiency if I moved to a mapped fuel injection too - but that involves spending a significant amount of money I would be unlikely to recoup on a car that I was planning on selling in the short term.

 

In that context (which I hadn't made clear previously) I'd rather keep the car standard - working well and in excellent condition, but without incurring the cost of significant after-market modification.

 

 

[IanWatson]

Update time.

 

Despite Andy's best efforts (huge thanks!) I've not been able to get a replacement ECU that fits to double-check the existing one - seems like there were more than one standard fit ECU loom and Andy's is not the same as mine.

 

I'm sick of the car not being used - it's been over a month now, so can someone assist with the possible aftermarket solutions? Obviously this will be needed for the ignition-map only as I'm sticking with the Weber carbs, so a full fuel/spark solution seems like overkill.

 

My mechanic has suggested Megajolt too (as above) - are there any good-value alternatives perhaps with a standard map for an XE on twin 45s?

[Allen Payne]

I've seen HPC's using the Weber Alpha(?) ECU which was ignition only. Have you tried any of the Sevens specialists - James Whiting, Seven Workshop - to see what they suggest?

[IanWatson]

Hi Allen

 

No joy calling Chris this morning, I've used him in the past so he was my first point of call. I spoke to Richard at Ratrace, he suggested sending the ECU back to MBE for repair.

 

I called MBE just now - what I have is a 905 (andy_h has the 904) - both of these were gel-filled to prevent tampering as they were produced for Formula Vauxhall use, plus the components are no longer available, so no chance of repair.

 

I had a quote for a OEM-looking turn-key solution including MBE 9A4I ECU, standard map for carb'd XE, wiring harness, coil pack, fixing bracket and machining the dizzy cap of around £680 inc VAT.

 

This is a 2D map, would need to add a TPS and another £100 for a 3D solution.

 

Given this solution need not involve a rolling-road set up, does this seem to be a good value solution?

 

cheers

Ian

 

 

 

1992 HPC on 45s

205 GTI Mi16

[Paul Deslandes]

you could advertise on BC or Pistonheads for a 2nd hand MBE 967 or 967i (which is ignition only) or contact SBD who are MBE's main agent. There are ignition-only maps around that can be loaded on very easily. You might even find a 2nd hand MBE 956 which will do the job just as well although, if you're thinking of going to injection at some stage, I'd stick to the 967 (not 'i') or current 9A4.

 

 

[Nick Chan]

On my HPC I had a very similar problem with the original MBE unit and a couple of electrical items that were nigh on obsolete but still available for a massive mark up (something like £200 for a 50p item!). Anyway I replaced it with a DTA 48i unit to which I added the loom, throttle pot and bracket and coil pack to make sure everhting was up to scratch. Back in 2005, it cost me around £650 but it was well it for the reliability and improved efficiency of the engine. And fuel economy definitely improved which was a big bonus on a VX 😬

 

Nick

 

PS Just remembered a quick trick you might try, run a negative feed back from the ECU direct to the battery. It worked on a VX that had a problem with no start up at all at first and this seemed to do the trick. It probably won't work but worth a try!

 

---

Back in a BEC! - but done alright in Class 1...

[IanWatson]

Quick update - I've bitten the bullet and ordered turnkey 9A4i package with the additional TPS and wiring so I can run the 3D map.

 

I managed to squeeze SBD down to an all-in including VAT and carriage of £750 (down from £810).

 

I'm fed up with it sat there doing nothing, and even if I'd fitted a period replacement I'd be worrying about reliability. Plus I'm hoping to see an improvement in economy and driveabilty.

 

thanks for all the help everyone - particularly Andy (btw you still haven't let me know if a bottle of red for your efforts would be appreciated!).

 

[andy_h]

Hi Ian,

 

I don't drink wine, but my wife would greatly appreciate a bottle of red 😬 Thank you.

 

Sorry it didn't work out for you, but I understand even if it did you would still have the worry that it could fail again in the future and you're back to square one.

 

My postage cost was £6.25

 

Cheers,

Andy

 

 

White road legal 2.0 HPC VX race car - Now all shiney and new 😬

[IanWatson]

Thanks Andy - I'll get the kit back to you with a cheque and a bottle of red.

 

I think it's worth the expenditure for the peace of mind - a non-functioning Caterham in August is a frustrating thing...