Porky EFI

Rich H · Post by **Rich H** » Wed Dec 05, 2007 8:36 pm

robin wrote: So measure the resistance - if it's about 5ohms that's right.

How is the heater wire driven - I assume it's via a relay and fuse rather than just commoned up to all the other +12 circuitry?

Cheers,
Robin

Its about 8 ohms or so and it has its own fuse, it runs off the main relay at the moment, is that bad?

I disconnected it as it was so low a resistance I wasn't sure if it had failed or not.

Ta
Rich

robin · Post by **robin** » Wed Dec 05, 2007 8:42 pm

Main relay + own fuse is perfect - I was just checking that the current wasn't coming back out of the MS PCB.

Cheers,
Robin

Rich H · Post by **Rich H** » Wed Dec 05, 2007 9:11 pm

No MS has its own fuse, and the injectors are fused in pairs too. Hopefully won't fry it all in one go!

Hopefully I have 3 wires to solder, a load of tidying up and some plugs to buy old ones are screw tops and I've lost the little adapters

before its time to throw a bit of fuel in and see if it'll start!

I can tune the low part of the VE table with the narrow band but I'm going to have to splash out on a wide band before I can properly get to grips with it.

Rich H · Post by **Rich H** » Wed Dec 05, 2007 10:30 pm

Wide band ordered.... More wiring to do....

I'm now waiting for:
Wideband lambda
Plug leads
Plugs
Time to fix it all together....

I have read the theory on tuning, is it really as simple as hooking it all up, making it idle, switching on the auto tune (MS Suppports on the fly tuning! Auto tune chases AFR) and going for a drive??

robin · Post by **robin** » Thu Dec 06, 2007 1:14 am

Short answer is, no, it won't be anything like that simple.

Rich H · Post by **Rich H** » Thu Dec 06, 2007 10:06 am

I didn't think so!

Good, it would be boring if it was easy....

On a scale of 1 (Changing the time on the clock) to 10 (Building a car from scratch) how difficult is it likely to be?

I'm hoping I can get it running OK quite quickly then spending the next few months tweaking things to get it running well. Is this a realistic plan?

gdr · Post by **gdr** » Thu Dec 06, 2007 10:35 am

My experience was that getting it running OK was easy, fine tuning not so easy (this was fuel only). I used MSTweak3000 on a datalog with the EGO active. Main problem was that it was extremely difficult to hold a constant RPM and throttle position for long enough when driving on the road (to get the EGO crossover points) - may be easier with your 944 than was with my Ultima - with my gearing it was impossible to hold constant revs with more than 3000 rpm on anything above 1/2 open throttle in any gear. The thing would just keep accelerating until presumably the engine would explode. Also risk of burning valves at high load.
I eventually got it mapped OK with a fair bit of trial and error (and one eye on the wideband meter esp during first track day). I think a session on a rolling road to sort it properly would be worthwhile once you are fully familiar with the tuning software.

2F45T4U · Post by **2F45T4U** » Thu Dec 06, 2007 10:41 am

the auto tune will get you in the ballpark. but it wont be great. and it can do nothing about ign table

if the MS has a map trace then its a bit easier. as you can mark flat spots while you drive and tweak them when you pull over.
my wolf 3D has a hand controller so you can kinda do it as you drive and smoothen out the 'lumps' on the 3d map later on with the laptop.

Rich H · Post by **Rich H** » Thu Dec 06, 2007 10:58 am

Cheers Chaps.

As far as the ignition goes the Porsche repair manual has the dizzy specs for mech and vac advance for dizzy testing. SO that should be easy enough to set to begin with. Its pretty low comp so the yanks take it up to 40 odd degrees.

Rich H · Post by **Rich H** » Fri Dec 07, 2007 9:41 am

Wide band lambda turned up this am, just before I left for work. But I'm working all weekedn so no playing until next week

(Well maybe a little playing...

)

It's an Innovate unit and it looks like a very professional and sorted piece of kit, well impressed! Thanks for the pointer Stu! I now have a little bit more wiring to do.

I think I will get the car running on the narrow band to start with just so I don't damage the wideband with a too rich mixture. Once I have the basics running and I have proved everything works ok, then I'll drop the WB in and sort it properly.

Does this sound like a good idea or shall I just wire it in anyway!

2F45T4U · Post by **2F45T4U** » Fri Dec 07, 2007 10:45 am

wire it in anyway. as long as its about 11" from the headers and on the top of the pipe then its fine. if theyre mounted at the bottom then the moisture gets to them. the LSU4 is pretty robust so itl be ok from the leanest to richest mixtures. its really only silicones, 2 stroke oil extreme temperatures and lead that kills them. if the mixture is rich enough to wreck the probe, then its VERY likely that your engine wont run anyway

i dont know about the innovate but my Zeitronix can simulate a narrowband and allow you to run with wide band for tuning and narrow band for closed loop if you only have one lambda boss in your exhaust. be worth looking into if you havent already

Rich H · Post by **Rich H** » Fri Dec 07, 2007 11:36 am

The Megasquirt can run closed loop on a wideband anyway, so its not a problem, it'll be going in as soon as I get the chance then!

Its about 3' down the exhaust, not ideal, but the only place I could really get away with mounting it. The problem will be mounting the controller, because of the location of the exhaust (Transmission tunnel) its going to be tricky to mount it somewhere safe. Might have to get a box to put it in, the case looks weatherproof but I'd rather not find out!!

The kit came with a spare boss anyway! If anyone needs a weld in boss let me know! Very imprerssed with this kit, it has all the optional bits thrown in with it. Lets hope it works as good as it looks!

Ta
Rich

gdr · Post by **gdr** » Fri Dec 07, 2007 11:39 am

I had the Innovate wideband which was good. Sensor survived some pretty rich mixtures for me with no probs.

Rich H · Post by **Rich H** » Fri Dec 07, 2007 1:03 pm

Rich H · Post by **Rich H** » Tue Dec 11, 2007 7:20 pm

RIGHT ITS ALL IN!!

And it works! But it won't start

Any of the EFI heros got any hints for setting pulse widths for idle?

Had to call a stop as its too dark and cold to continue. Got a couple of splutters out of it but no start yet. Just need ot keep trying to richen the mix until it runs.

Got the weekend off but need to do xmas shopping

but otherwise should be able to have a good crack at getting it started.

Once I have it idling (!) then I can play around wth the wideband to tune the VE tables.

PS wideband lambda sensors work alot better is you plug the computer into the right socket...