Megasquirt a 4.5

[JoeyTheB]

Ok, I "done with Djet". ECU is emitting infamous burned transistor smell. GREAT.

I'm tired of chasing down components from the "Saturn Five" era to fix/tune my car and am planning a conversion to megasquirt fuel injection.

I found some great info on a K-jet 4.5 SLC conversion on the web.
D-jet should be much easier assuming I can reuse my bosch/blue injectors.

Has anyone done it here or have words of wisdom to impart ?

I'm thinking this is what I will need:
MS II Kit + Test Board
Relay Board
Relay Cable
Use MS II On board map sensor
Use MS II on board Flyback Board for my low impedance injectors
Use Volvo TPS sensor (found one already, just need to mount)

Wideband O2 sensor Kit
*Where should the o2 bung go ?

Reuse the air temp sensor (tests ok)
Reuse the coolant temp sensor (tests ok)

Run MS off coil -
(I'm using the crane xr3000 unit)

Future:
Try different injectors
Try different air intakes

Install 36-1 trigger wheel w/vr pickup (off ebay)
Go dizzy-less - 2 coil packs and EDIS 8 module.

[Gurunutkins]

Hi Joey the B
I know the feeling, I am currently doing a d jet conversion on my 450sl and had a lot of help from a guy oughtsix. here is his website, he has done a CIS 450sl (here is his website http://www.hitechengineering.net/DNN/MegaSquirted450slc/tabid/54/Default.aspx ) which is harder, also look at this thread from another benz site

http://www.benzworld.org/forums/vintage-mercedes-benz/1318045-replacing-bosch-jetronic-megasquirt-efi-print.html

sorry I cant use tiny url for this site.

There is a lot going on. I wouldnt bother with the MS11 just go with MS1 with msnextra code. I am currently working on the edis 8 ignition for my system as well.

good luck
len

[Tomguy]

Honestly, I would not reuse the D-Jet injectors, they're VERY high flow and I feel that a lower flow injector with a wider width would atomize the fuel better for more mileage.

That having been said, I've looked into it before, and it does seem very do-able, you'll need a new MAP, temp sensors, and a way to mount a new (REAL) TPS as opposed to the Throttle Position SWITCH the D-Jet has. Oh, and drill a hole in the exhaust for an O2 sensor honestly. Do it right. Use a heated O2 sensor, wide-band.

[JoeyTheB]

Re: Injectors etc:

Tomguy - I'm with you the injectors.
Modern 4.6 l engines use the 19 lb/hr injectors. HP engines can use 24 lb/hr (and up). Guess what rating the blue djets are ?
39 lb /hr !!!! -- That's more than twice the 19 lb/hr.
Now, I know nothing about injectors except the new 19 lb/hr ones are a lot cheaper than the premo expensive blue djet injectors !

Guru - Is MS 2 not up to match MS 1 + MSnExtra ?
I read that was the case a while back, but has the MS2 software caught up yet ? It appears the hardware has...

[Gurunutkins]

hi Joey
I will probably get flamed for this but the ms2 system is great but the software is nowhere as good as the hardware, and they are concentrating on the sequential injection now so the software probably wont get a lot better. with msextra I can control a stepper idle air valve instead of the expensive water temp idle air valve on the 116 and 117 engines, I can also control spark with a simple edis system off a ford v8 (although I love my pertronix) and best of all you loose those stupid distributor points for the efi system.

remember too with the injectors that so long as they work you now control the duration they are open so they may be capable of injecting 39lbs but with the software you can inject them 4 x per cycle and only inject the equivalent of a 19lb injector over the 4 events!

the TPS has to be replaced, I used one off a 1991 SAAB from the scrapyard for $5, works perfectly. use easytherm to calibrate your existing sensors to work for the megasquirt and you are away
cheers
len

cheers

[GaryF]

Originally Posted by Gurunutkins

hi Joey
remember too with the injectors that so long as they work you now control the duration they are open so they may be capable of injecting 39lbs but with the software you can inject them 4 x per cycle and only inject the equivalent of a 19lb injector over the 4 events!

I think Tomguy's point is valid that a lower flow rate injector with a finer spray pattern will be more efficient in atomising the fuel than pulsing a high flow injector.
From what I've read about this conversion its not an overnight change, some guys seem to spend years refining the setup. It would be nice to pull an engine and spend time on a dyno getting it just right, I can imagine tracking down driveability issues being a long process.

[Housecrew]

what do you guys think of the injector upgrade for 4.5 liter engines from this shop?

http://netcomparts.com/MBspecials.htm

8 injectors - Bosch
increases fuel ecomony and power up to 25%
2 simple electronic adjustments to be done

you think itīs worth the money? or do they only use the 3.5 injectors?
i have an euro spec 3.5 engine here in my garage where i can pull the injectors from
but i donīt want my 4.5 to run too lean/rich. any ideas?

greetz from germany

[Tomguy]

3.5 injectors, according to online resources I can find, are rated the same as 4.5 ones.

What you want is modern injectors (with a custom fabbed fuel rail presumably) that will have a lower rate of delivery but better fuel atomization to better combust and raise efficiency.

[darkstarmedia]

Hi,

I am very interested in this one... I have a D-Jet (75 450 SEL) that has not run in 10-15 years that was parked due to a bad fuel pump (I think). It has some other minor issues but that is what brought it down. I currently have the cams out and going to swap in a set of euro cams that I am grabbing from a k-jet 4.5 of the same era (I hope that will work). Any ideas on a fuel pump that won't kill my wallet? Also, is there an easy way to drain the tank. It has been years since I have been in the Merc but I do remember pulling something in the trunk to get to the tank but not seeing a drain.

Thanx,
Richard

[Tomguy]

Originally Posted by darkstarmedia

I currently have the cams out and going to swap in a set of euro cams that I am grabbing from a k-jet 4.5 of the same era (I hope that will work).

1) You'd BETTER make sure they're euro or you'll be giving away 20HP
2) You have to swap the heads with the ones from the donor so that you'll have hydraulic studs instead of mechanical ones. When MB swapped from D-Jet to K-Jet they also swapped from mechanical ball studs to hydraulic ones and hydro cams are NOT backwards compatible. You can install manual studs to the hydro heads (it closes the oil passages) but your heads dont have oil pathways, you need to swap them! If not, your engine will probably seize on the first start as the valves kiss the pistons.

[darkstarmedia]

bummer.... I am in Southern AZ and my mercedes is in a garage in California... I am going there over the xmas break and try to reassemble the motor and start it... any ideas on the other questions... cheap fuel pump, tank drain? If I can get it running enough to start and move I can get it transported to AZ much cheaper.

Richard

[cth350]

A used fuel pump on ebay works, as will visiting a pick-and-pull. If you can't find a djet car to get the pump from, a CIS car that has a single pump (not the fancy dual pump setup), that will work too.

The practical way to drain the tank is to disconnect the hose from the fuel pump, which you're going to do anyway. Have a vise-grip on hand to close off the line and a gas can that can lie flat and you should be in business. worse case, you've got about 20 gallons of fuel to dispose of. If you're lucky, it's already down to a quarter of a tank or less.

It would be a good idea to replace that hose entirely after this much time, but that's harder than it sounds.

-CTH

[darkstarmedia]

Thank you for the fuel pump tip... Is there a prefered place for on-line parts. Looking into the future there are some other mods I have been thinking about. It currently has the 3 speed automatic, is there a 4 speed automatic (I want overdrive) theat will bolt up to the 4.5L (5 speed automatic would be cool too...).

Richard

[Tomguy]

There's a 4-speed auto but no OD tranny. The 4-speed auto from early 3.5's will bolt right on (it's fluid coupling vs torque converted so shifts will be slower and harsher, but it will be faster from a dead stop).