Fuel Injection

[john.p.clegg]

For not a lot of money you could get.......

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... _500wt_975

John

Now using it as my home laptop and tuning (serial interface etc,etc),etc.....y

[seaandmoor]

Hi David,
yes I've got a converter to USB and it works fine for any other application. However, you will find (and it is not generally known) that you cannot successfully use a cable converting to USB when tuning with your laptop and is the very reason why megasquirt is equipped with the port that it has... USB's are the cause of anomolous misleading spikes which are not easily detectable. The car runs when you have finished but you are going to have problems without realising where the problem is and it'll be difficult to achieve the best map that it's capable of.
Just forget converters and get the correct laptop port to match the port on the megasquirt - it's one less problem to deal with!

[msd1107]

Interesting.

I have an old portable with a parallel port, but it dates from 1988 and runs Win 3.1. Not a likely candidate.

Searching the literature for USB voltage anomalies, they exist, but not during normal operation. Not to point fingers, but if the equipment is sensitive to voltage anomalies, the input should have the appropriate voltage protection built in, not depend on the customer to provide it.

Having just gone through the qualification process for a USB peripheral to the iPOD, this should have reared its ugly head. Apple has a comprehenhise qualification process for foreign peripherals to get the "Made for iPOD" logo. The product has to remain within the USB voltage of 5 +-10% or 4.95-5.05v. Our first run had 4.9v and failed and we had to change the voltage regulator.

FI is notorious for its sensitivity to the car's electrical environment. Multiple grounds, shielded connectors etc are necessary.

Perhaps what is necessary is to shield the cable from the computer USB port to the parallel connector - maybe with something as simple as wrapping it in aluminum foil. The parallel cable has multiple grounds that probably make an effective shield for the few active lines.

Does any body else have any experience with this?

David
1968 36/7988

[tdafforn]

Hi all,
Comment on screening and earthing can't be emphasised..
My MS setup works great, EXCEPT, on startup, when the EM interference badly effects the crank trigger output (even with a screened cable! This causes mis-fires/backfires (partilcularly when cold).
It is really driving me mad.. Car runs beautifully on MS once fired up!
have redone all earths and taken clean supplies from the battery..
My last thought is that the interference is getting in where the crank trigger wire connects to the MS loom. Not sure how to test this?
tim

[john.p.clegg]

Tim
Are you using resistive plugs?

John

[seaandmoor]

David - I'm not disagreeing with what you say but I was trying first of all with a fully screened USB to nine pin port connector and still got the 'spikes'.
So I thought why bang my head against a brick wall when the quick solution is to use a laptop with the correct port. Bingo! and just get on with the tuning and get on the road!

Tim, forgive the question but do I understand you that you have specifically identified interference only when cold (!) OR you have a general starting problem when cold but otherwise it's great when hot.
I don't think it will be anything to do with the screening of the crankshaft sensor or the cable from it to the MS. Do recheck earths though (critical in a fiberglass car), the gap between sensor and trigger wheel (this might change as the radiator and exhaust heat up the bracket, the temp sensor which can fail and the air fuel ratio/enrichment in the cold start 'wizzard' first and see if there is any change. Who supplied you with your MS? Are they able to provide you with any starting point with an MSQ file to save onto the MS?

[pauljones]

i wish to get my twin cam FI,if the diy version is around the 2k mark and similar to a bespoke webber alpha system,then is it not better to go the "proper" way when you know every thing works together.???

[john.p.clegg]

Paul

Where's your sense of adventure,you might as well get a Mondeo?

John

[seaandmoor]

Here here.

Sometimes you're lucky with the initial installation and you don't get any problems - other times you will need some patience and a methodical mind to work through it in a 'flow chart' manner. Once you are there though .... well I would never go back - the quick response, knowing the AFR is correct, the advance is correct, corrections for cold start/hot start, extra fuel instantly when required and smooth from idle to red line. It's light years better. This is all provided everything else about the engine is in good condition and working properly.... if it isn't, then of course MS won't fix worn cams, valve seats, piston rings etc
I'm hopping onto a different thread now. Good luck. Cheers.

[pauljones]

id love a mondeo,2 ltr if i could.go well with my spyder chassis,5 spd box and 3.54 diff,(soon to have an ATB in.) as it is,i saw a mega squirt ecu on ebay for ?150.now thats a big savings,but what do people use as TB's? i think in the old days you could adapt 40dcoe carbs,but id still prefer to use the real deal.only trouble is there very expensive and need all sorts of extra bits.so why not go get an off the shelf system and use our beloved cars the way they should be.

[memnon]

Jenveys are well sorted off the shelf items, but bike throttle bodies offer the same sort of performance if you like the challenge of making them work (they come from OEM's remember!)

I went Jenvey because I found a pair on ebay at a good price c/w injectors, fuel rail, throttle sensor . . . for the same price as a new pair of jenveys without all the stuff.

ECU's to my mind are basically brands. IF you know what you are doing Megasquirt is the way to go (kind of like linux for the PC, its cheaper but yuou have to understand it. Otherwise you buy windows)

I am new to ECU's and the like but want to learn, so I am getting his one set up by my engine builder, he happens to like MBE, so thats the way I have gone, once I understand how it works I'll pick whichever I want to for any future project.

[john.p.clegg]

Just reviving an old thread..

For those of us who are running Fuel Injection...what sort do you have....is it fit and forget.....what backup/support do you have....thoughts..

John

[memini55]

Hi John,

I will try to help this along also. I am nearly ready to make my system run, finishing up some wiring details.
Running a Megasquirt with TWM throttle bodies, RCI Injectors, Bosch pump, Redline fuel regulator and Haltech wasted spark. The crank wheel/pulley from QED which included the sensor and bracket.

I have attached a couple pictures.

Mark

[gjz30075]

Mark, I'm anxious to know how its going to run and whether or not its worth it, over webers. You have an electric water pump hiding somewhere?

Greg Z
'72 Sprint

[memini55]

Hi Greg,

I have Davis electric pump and it can be seen in picture #4 if you follow the lower hose. It sits on top of the cross member of the frame. That part works almost too well and I am still dialing it in with programing. I also have a large aluminum radiator in the nose.
I'll let you know on the running part but it will be sometime before it gets out for driving. Dead of winter and we have more that a foot of snow holding on the ground. Been there since mid December.

Mark