Mongo

I am pretty much at wits end dealing with all of the electrical issues related to fuel injection on my car. It has been a horrendous experience lately. Though I have considered selling, it would actually be counter-productive and uneconomical to get rid of it and get an older car. Instead, the money can be invested in not only rewiring the car, but upgrading the fuel injection to standalone.

I have reviewed Carl's Electromotive Tec GT threads and have read pretty much the whole online manual to familiarize myself with it. It is a great system, but it's a little pricey. However, the price justifies the ease of installation of a kit that can be wired into the 928 in a weekend without having to run to your local CNC guy for extra work on fabbing mounts up.

Then, there's Megasquirt. I have seen some great threads on these forums from the 944 area to this one about doing MS conversions. Colin and Tom M's threads are packed with great info on using MS and an EDIS-8 hybrid setup to adapt to the 928 and have yielded incredibly successful results. The price is a lot less than a Tec GT kit though, but may not be as easy to install. I haven't figured an exact price for all the parts yet, nor do I even know what I need to buy for a Megasquirt conversion (Colin and Tom chime in if you want and let me know what sensors, wires, etc. would need to be picked up to do this, including what MS box to use).

I do know that with the new EFI systems out, most of the headaches go away, but you get introduced to a new one... tuning it on the dyno, which could be expensive also.

I would like to get some feedback on you MS guys out there and how you got yours wired up. Also, how do you get the flappy to function on a Megsquirt setup?

John Speake

And get a knock detect and cotriol system as good as the one in the EZK ?

SQLGuy

Megasquirt can support the knock detection. The main catch I can think of would be the resonance flap. You'd probably need to run MS2Extra (third party, and more easily modifiable, code for Megasquirt) so that you could add code to control the resonance flap.

Alternatively, you could use the Raven? RPM controlled switch to flip the flap.

It's also possible to leave EZK for ignition and run Megasquirt just for fuel. You could use MAP or the stock MAF, or both.

One problem I know of with all the Megasquirt code, though, is altitude adjustment. If you'll be driving at varying altitudes, you'll want to add a second MAP sensor and significantly modify the stock baro correction curves. It's not that MS can't do it correctly, it's just that the stock corrections were done wrong (IMO)... they actually richen the mixture at altitude instead of leaning it!

One other thing to consider is that, with MS2Extra, and a few extra parts, you could run four channel semi-sequential injection, rather than batch fired. If/when the MS Sequencer is available, that could provide full sequential injection, and even COP for the 928.

Cheers,
Paul

mj1pate

There is some experience out there. I believe Lizard931 has quite a bit of experience with after market ECUs for the 928. I had some strange engine cut-outs early on and was about to give up on LH, but sorted out the actual cause (not LH) and have been trouble free for years. As mentioned, changing over will likely present its own challenges in idle, engine anti-knock and other areas, but none of this is insurmountable.

hacker-pschorr

+1

whatever problems are plaguing you today will have the same effect with any other system.

If the Shark Tuner wasn't available it would be a no brainer to switch. With the ST on the table, I see little to no reason to go stand alone unless you are builidng a highly modified car.

blown 87

I agree 100%

SQLGuy

Reasons:

1. Semi-sequential injection with MS2Extra, fully sequential with MSIII
2. Use any desired injectors and correctly control injection times
3. Full data logging, and, with laptop connected, live viewing of all sensor data
4. Launch control, if you want it
5. With MSIII, full COP or other wasted spark distributorless ignition
6. Ability to run pure speed density (MAP, no MAF) if desired
7. Better control of such things as hot air ignition retard and rev limiter
8. Closed-loop AFR with a wide band O2 sensor
9. Integrated spark and fuel control, from one set of sensor data and one ECU

On the down-side, getting the fuel map and warmup parameters really right can be tricky. Stock MS2 code doesn't support closed-loop idle control, but MS2Extra and MSIII do, and can work with the Bosch ISV.

Bill51sdr

^^^ This.

Fix the problem.

Lizard928

Having done a number of MS installs I can say that converting to MSII is easy.
But I can say that there always seems to be a getchya which will have you scratching your head.

I run MS II extra 2.1.0 code on all the installs and use tuner studio.

I can say that you do not need to have the car dyno tuned and can get a good tune on the street.

While a knock sensor can be really nice to have, it should not be required unless you wish to squeeze every last ounce of power out of the engine. But just by converting you can gain more power from a stronger ign system, and more accurate AFR.

As well there is no need for MSIII unless you have big plans, going full sequential, while it is a nice technological feat, it is not required and will net minimal gains for tons more work.

I think that your best bet though would be to have someone find the problem in your car, or to have someone convert your car to MS. I mean no disrespect by this, but if you do not do every connection on the harness perfectly. And do your grounds properly, you are going to be chasing ghost problems afterwards.

As well you need to decide in advance what features you want, and build them into the harness from the get go.

Oh and you dont need the extra code to trigger the flappy solinoid. That is actually one of the easier things to control.

SQLGuy

Can you provide more detail? I am running MS2Extra with Microsquirt on a different project. I didn't see an easy way to say, "Fire this output port when RPM>3000 and MAP>70KPa...." without code.

Thanks,
Paul

Lizard928

I ran the flappy actuation on non extra code on Tom M. car without too much trouble.
There is a section to turn of/on spare output ports.

I prefer the extra code now and running tunerstudio.

SQLGuy

I see what you mean... at least with Tuner Studio, I can set a rule for a spare port to fire based on RPM and load.

IcemanG17

For a "street" car your better off fixing the LH system.....chances are its somewhere in the 20+ year old wiring harness...probably grounds..... worst case scenario is get a new wiring harness and replace-clean all the grounds and it will be rock solid for another 20+ years....

Bottom line is the EZK knock detection is VERY good & hard to replicate in aftermarket systems....

hacker-pschorr

I recently finished tearing down a harness, taking off all the ends, installing a new sleeve and connectors.

I was ready to replace any worn / corroded wires. Much to my surprise only the very ends of a couple wires were "bad".

I would be tempted to do this on any 928 as a winter project. Not only does the new mesh sleeve look better, piece of mind knowing all my wires and connections are good.

danglerb

The grass always seems greener on the other side of the fence, but this sounds more like out of the kettle into the fire. Why not drive the car down to Greg and let him fix it so you can start enjoying it again?