Any electronics/fuel injection ECU wizards out there?

Post by **pettaw** » 26 Apr 2005 07:25 pm

Ok, so the first days experiments are over. Putting it in as a starting relay only thing doesn't work. It's got to be there a lot longer, really until the engine just warms up, which I guess is about 2 minutes.

I've found that 4.7K resistor wired in parallel works well. The OEM NTC is about 2Kohms at 20c and so a 4.7K means the ECU sees a resistance of about 1.4K which means it thinks the coolant temp is about 40c. Perfect.

I'm still working on whether to leave the extra resistor permanently connected or just for about 2 minutes using a timer relay, such as these available from RS.

Edit: the url link thingy doesn't work unless you put it at the end and spoils the flow of my post so if you want to see a picture of what I mean you have to go to : http://img-europe.electrocomponents.com ... es/C342714

Edit: fantastic, so just typing it works too. Never knew that!

Trouble is it costs 75 quids, well the base costs 43 quid, then the relay itself another 10 quid, wiring, delivery etc etc.

I reckon it'll probably make little difference if this graph of the sensor resistance vs temperature is to be believed.

I'm going to wait until it gets really cold like tonight and then do a full run up to temperature.

Post by **pettaw** » 27 Apr 2005 04:36 pm

grizlyadams wrote:im with the fin...coughmegasquirtcough
Griz

Thats altogether not a bad idea, particularly because the car already has EFI, I only need a TPS, intake air sensor and lambda sensors, together with a lot of wiring, and obviously the megasquirt kit, if they sell it in this country.

I'm experimenting with a large capacitor to hold the voltage down for a number of seconds whilst the startup enrichening etc is happening. Almost got a circuit together, Probably the acid test tomorrow when car is completely cold.

Post by **jtbo** » 27 Apr 2005 05:15 pm

It is possible to left lambda sensor out, but of course tuning is much easier with one

I think that Megasquirts are sold in every country, at least in here you can buy assembled megasquirts around 200 euros. Individuals build and sells them.

Conversion is possible to do in one evening if everything works out ok

Post by **pettaw** » 27 Apr 2005 05:30 pm

I kinda like the idea of assembling all the components myself. I'm reasonable with the soldering iron, provided I can take my time over it.

Also where to get the wiring connectors for the injectors too. I know I COULD butcher up my old loom to get all the connectors but frankly thats a bit too dangerous, even for me and means I can't go back in case it all goes wrong:)

Post by **jtbo** » 27 Apr 2005 05:55 pm

pettaw wrote:I kinda like the idea of assembling all the components myself. I'm reasonable with the soldering iron, provided I can take my time over it.

Also where to get the wiring connectors for the injectors too. I know I COULD butcher up my old loom to get all the connectors but frankly thats a bit too dangerous, even for me and means I can't go back in case it all goes wrong:)

Cheapest way is to use those mini abicos, but much better is to buy used wiring loom from some car that uses Bosch injectors.

Of course, it is possible to use original loom, if you can make connector/adapter for original connector, perhaps possible?

I bought complete Opel Manta injection system, ecu is dead, but all other parts were more or less ok. It cost around 100euros and I took those connectors from it. Now I plan to sell rest of that around same amount of money as I did pay from it.

I did small Google searching and found some info:
http://www.v-8.org.uk/forum/classdetail.asp?id=291

http://www.americanv8engines.co.uk/?Pro ... ccessories

Post by **pettaw** » 27 Apr 2005 06:28 pm

Thats a great idea, all I have to do is get a male 25 pin connector that will fit the original loom. I already know the pin outs because its in my books.

Now where do I get that from ......

Post by **jtbo** » 27 Apr 2005 06:33 pm

Perhaps you can fing broken ECU and you can desolder connector from there and with little work you have adapter

Post by **foggyjames** » 28 Apr 2005 02:21 am

Are you guys sure that all of these GLTs idle like poop (especially when cold) by design? I'm stuggling to imagine Volvo would let their flagship model run like a dog compared to the carb version!

They all seem to do it, but I think this is indicative of some common (minor) component failure. Anyone want to hit a rolling road for starters?

...Not that I want to discourage anyone from going for MS!

cheers

James

Post by **jtbo** » 28 Apr 2005 04:56 am

Because it is running too rich, one thing that come to my mind is extra air valve, or what it is called. It could be dirty or something like that and because no or too little extra air then it runs too rich.

Post by **pettaw** » 28 Apr 2005 08:11 am

The Auxiliary air valve, that's what I thought too. So I changed it not long after I got the car, along with the thermal time switch, the cold start injector, the fuel pressure regulator and the coolant temperature sensor.

Made sod all difference and I was very disappointed. All of Pete's 360s do it and hes got about 20 or something

And I've ordered a Megasquirt kit + stimulator board. Now all I need are the TPS, Lambda and loads of wiring!

Post by **pettaw** » 28 Apr 2005 09:38 am

Oh, yeah, do I need to tell the insurance company? about the MS conversion?

Post by **grizlyadams** » 28 Apr 2005 09:55 am

well there is someone making an adaptor to make MS plug and play with lh2.4....juut MS at the moment, not spark yet

programable ecu...dont know what your talking about officer... (stick it all in another bosch ecu case and who's going to tell).....

Griz

Post by **pettaw** » 28 Apr 2005 10:05 am

Eureka, it started fantastically this morning, no spluttering and not too weak. Just a nice start.

Patched a large cap (4700mcF) in series with a 1K resistor across the CTS terminals.

Have discovered in the process how the enrichenment thing works. It must have a reference resistor somewhere in the ECU, and then use a voltage divider circuit, because the voltage was over 6V yesterday on a full cold start. Dropping very quickly to about 4V and then right down to 0.7V when hot. The interesting thing is it then increases when you put your foot down too, to about 1.4V.

Anyway, with the cap circuit in, it started at about 3.5V and then gradually rose to about 5.2V by which time the CTS is already warming up so it then slowly drops again. It never got to the high voltage that caused the spluttering.

The actual first firing of the engine is always controlled by the cold start injector, so I don't see why it wouldn't always work in all conditions.

I'm happy now, but I'm still intending to put MS in eventually. Ha, with the way the parts ordering is going, I'll have the MS assembled, tested and fitted before those conrods ever arrive.

BTW,I decided to go for new conrods, because the little end bushings were rusty and worn out and I reckoned that by the time I'd paid a machine shop to fit and ream new bushings it would have cost only slightly less than brand new all ready-to-go rods. Now I'm regretting it because that's the only thing holding me up, otherwise EVERYTHING is ready to be rebuilt and assembled.GRRRRRR

I'm not so happy now

Post by **foggyjames** » 28 Apr 2005 11:13 am

*Get the 13mm ones from a later engine*

cheers

James

Post by **jtbo** » 28 Apr 2005 03:56 pm

I used Volvo V70 TPS for my Megasquirt installation. With little modding it fits perfectly and does not cost too much in local parts shop.