stevieturbo wrote:Perhaps, but Ive never seen them fitted to any modern car.
The last car I seen with one fitted, was my 1998 Volvo that still used a dizzy and single coil.
Ive never seen a modern engine with them.
Might be some confusion here.
On points ignition, there is a cap across the points. It forms part of a tuned circuit and is essential to the ignition. But you will often find a second cap between coil positive and ground - that is to suppress radio and TV interference, but has no effect on the actual ignition function.
With EDIS, the cap performs the second function. But may also suppress spikes etc from getting to the ECU or other electronics too. So may have an effect on the running.
Dave
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y
I am no expert electrickery wise - trying to get the magic smoke back into the wires after a fault is far too difficult - but whilst investigating ECU's for various projects faults that you are describing could be caused by a dying/faulty alternator as this can upset ECU's by producing transient spikes through dying diodes - The battery generally does a good job in soaking these up to prevent real damage to circuits but they can cause trouble as can low voltage periods through a dying battery cell.
Remake / check the main chassis/engine battery earth paths
ETA
Another recent thing brought to my attention in PPC with Dave Walker - make sure you have the correct resistor type spark plugs installed.
it's hard to understand how the ecu file could become corrupt. Although at the time....did you inspect the map or sensor readings etc before reloading ? To see exactly what state it was in ?
Are there any sort of diagnostics within the ecu ? looking now, does everything seem totally normal ? No strange readings anywhere ?
it's a pity there wasnt any logging available to see just what was going on, and to see if the ecu was actually dumping loads of fuel in deliberately, and if so why.
Logging is a feature every ecu should have running full time, for so many reasons ! It just helps track down past and current issues, and helps tuning too.
Upgrading for that feature alone would be worth it IMO.
the worry i have is once the charger is fitted i cant afford for the ecu to go screwy and melt something by going to lean, same as now if i run the nitrous,
Vems is a good ecu don't get me wrong but i have been plagued with some many problems with this unit that i have had enough,
A mate who is an electronics guru and builds boards for a living is going to take the ecu apart and check the board over to make sure every thing is ok and try and tidy the board up, then i either keep it or sell it on over on the vems forum,
Another thing which is good going to the MS 60+% of the efi guys on this forum i recon are MS users so help and tunning will be a lot easier,
when we had the v8 rolling road day the guys there including eliot (thanks) would of been able to help out with tunning the car,
Phil has been a great help over the past few days, and is a top bloke,
regarding the alternator,
this problem happened with the old 3.9 engine too with a different alternator, and also now on the 4.6 with a different alternator, the battery is different too.
we did have spike problems in the early days as Marki etc knows from posts on here, it turned out to be a problem on the board which vems sorted, due to a chip or instalation fault cant remember now after that no spikes popped up on the datalogs.
Battery lines and earths were also changed when the new engine was fitted 2yrs ago,
like i said its been running ok but when the battery went flat in june we had to upload the ecu file to get her to run, then again this week theres no real pattern it just does it for some reason,
Wiring can get you in odd ways. I had a fault where about every third time I went to start my car with an MS1 the ECU would be non-responsive. It was actually stuck in the bootloader, something I thought wasn't possible without shifting a jumper in the case. I traced this back to the fan relay. The + side of the relay switch was wired to permanent feed. When the ECU was switched off, this left the switch signal from the ECU floating as +12v, which was enough to keep it powered but confused.
Whats the VEMs worth? Looking at the software it seems a very capable system, must be worth a fair bit of cash, more than enough to finish the blower
Phil
Another vote for sorting the supercharger.
4.6 has great low down torque but can run out of puff!
The centrifugal supercharger was 'born' for this engine (well you know what I mean! Should say this engine was born to be centrufugally supercharged!)
My 4.6 has just a mild cam and only a 3 angle job on the heads and with just 2.5psi it takes off above 2500-3000rpm and at 5psi and 5000rpm I have to back off as i'm a pansy! Roll on 10psi
If you already have the head unit seem like a no brainer to me!
Wrt to the old VEMS system, are you sure it wasn't enabled for some sort of autotune feature where it actually adjust the VE's bins on the ECU according to wideband feedback(or lack thereof) - reflashing the code would revert the map back to original and explain why it restarted.
What you should of done is saved the map FROM the vems when you had the problem, before burning your default map back down - then you could compare it.
Just for your info Coops, My large bore plenum 4.8 made 276bhp and with 50mm throttle bodies it made 302bhp. The tb's were too big for the engine really but they're now on my 383 sb Chevy
Cobratone wrote:Just for your info Coops, My large bore plenum 4.8 made 276bhp and with 50mm throttle bodies it made 302bhp. The tb's were too big for the engine really but they're now on my 383 sb Chevy
Tony,
Out of interest, do you have the graphs for both, including the torque curve?
Phil