Hi Tom.
First of all, Excellent post! I understand your frustrations!

I am fortunate to have one good AAV, two good MPSs, two sets of injectors and my ECU "seems" to be OK. Having a full time wideband AFR readout allows me to finetune the MPS and ECU mixture settings manually (which an MS will do automatically once run on closed loop).

It was GGR who mentioned the Nissan injectors. He will have part number info. But bear in mind that those injectors, like the D-Jet injectors, use rubber hose connectors, not a high pressure rail system like the one Mike described.

GGR,
If it is a D-jet that you are converting, the original fuel pump is different from later pumps, because it has an internal relief valve.

I don't know at what pressure it relieves pressure back to the suction, but I believe this was meant to protect the fuel supply system (that uses hoses and clamps to contain the fuel).

I was told by Bosch that K-Jet (and presumably aftermarket EFI pumps) should not be used on D-Jet cars because they lack the relief valve. So if you use the Nissan injectors, then presumably you need to keep the pressure down to a safe level or provide an external safety relief.

If I was doing MS, I would like to boost the fuel pressure and get away from the vapor locking that is a common problem on low pressure D-Jet systems.

We haven't heard from barri (gurunutkins) for a while. It would be interesting to know how he and others who have converted MBs to MS are making out.

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Graham
85 300D,72 350SL, 98 E320, Outback 2.5

Well, my case is a bit of a particular one (integrists, please look elsewere now!)

My engine is a euro 5.0 M117 which originally came with a Kjet system. I have replaced the intake manifold by a D-jet one out of a 4.5 (same ducts and TB diameters as the 5.0 K-jet) as I want to go Megasquirt and the 4.5 intake manifold was designed as an EFI one from the beginning. That engine will go in a W111 Coupe currently equipped with a D-jet 3.5. So I will be using the D-jet fuel pump with the relief valve. I checked the pressure before the FPR and it is over 50 psi, so it will be ok to deliver the 43.5 psi if needed. Also, L-jetronic systems used hose injectors witha a 43.5 psi pressure, so I think I'm safe with properly rated new hoses everywhere on the D-jet fuel circuit.

Graham, thanks for your post. Sorry about my confusing you with GGR, whose comments are much appreciated as well. (Thx for the injector part#!)

After doing some research on the Nissan injectors, it seems that the pressure spec for the 280ZX application is 36psi. This is only 7-8psi higher that the Djet spec. It seems that it would be safe to use the existing Djet fuel rail with the Nissan injectors. I'm not trying to re-engineer or fabricate anything I don't have to. The next questions are:

1) Can the stock Djet pump put out 36 psi?

2) Can the stock fuel pressure regulator be adjusted to 36psi output?

If yes to the above, (and GGR's latest post indicates this is so) is there any other reason to believe that this injector setup would not be a good plan in conjunction with the Megasquirt conversion?

Tom

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1972 280SE 4.5

Tom, I'm aiming at 275 hp as the engine is now, may be one day 300 hp with more aggressive camshafts and a bigger TB out of a 560. This is why I went with 280cc injectors that will be able to deliver up to that power.

In your case, if you keep your engine stock, I would seriously consider the Bosch 200cc out of Volvos and VWs. They will be better adapted to your purpose. They are hose injectors and will be straight fit. The Djet FPR can surely be adjusted to deilver 36 psi, and the pump will also deliver above that. But Megasquirt recommends a vacuum actuated FPR to keep a constant pressure differential through the injectors, allowing a much easier and more intuitive tuning table. In our case, the WV Vanagon gives us what we need. No engineering needed with these injectors and FPR.

I have experimented with pressures of up to 35 psig on my Djet without problems. But I guess the higher the pressure, the higher the likelihood of a leak.

The FPR should be able to be adjusted to 36 psig. But as GGR said, the D-Jet FPR does not have a port for manifold pressure input (because the MPS knows the pressure). Idle manifold pressure is 20in vacuum and full power atm pressure - Can MS adjust for this without a vacuum adjusted FPR?

Regarding the fuel pump. Should be fine, provided there is sufficient flow at the higher pressure (~2L/min). One other forum member reported vapor locking when the pressure was increased, possibly due to leakage through the relief path or perhaps just lower circulating flow.

Good Luck with the MS. I won't do it unless I really have to. I would really like to hear how the pioneers are making out first

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Graham
85 300D,72 350SL, 98 E320, Outback 2.5

Mike D, what harness are you using? Did you make a new one from scratch? I was thinking of looking into an M119 one. I don't want to reuse/modify my D-jet one as it is all brittle.

Tom I like the thread, I am also gathering info on the same project. And I am going to use a MSD spark box w/MSB blaster coil, and I want to drive this car around.

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30 yr's still in love

I have to make my own harness. My project is on a K-jet engine.

Hi guys nice discussion, Alastair in Oz sent me an email to have a look and give a quick update.
Ive been running the MS1 on both my d jet 450sl and the 76 k jet 450sl for almost 2 years now with the same settings and almost identical VE maps (slight differences only). I just love it - long term on the 450 d-jet (which I drive most of the time) i am getting just over 18mpg average with as much power as i need. she starts first time every time and I have not had a single problem with MS on either car. With both I used the MS relay box and built the wiring harness I have both an A/F ratio gauge and a fuel pressure gauge in the cabin so I can keep an eye on them. I run the standard 450 (bosch 036) injectors on both 450's and I run a CIS fuel pump on the djet instead of a standard djet pump. I had the pump on for about a year before I converted and the pressure regulator pulls it down to 32psi without a problem (been running like that for probably 3 years) and obviously the supply from the CIS pump is not a problem either. I did think about running smaller injectors as I have the originals right at the limit for idling (the lag time on the older injectors slows them down over more modern injectors). I have a set of injectors out of a nissan ZX and will try them at some point. I run the d-jet on pertronix as well and use the coil fire signal for the MS signal. Its now as reliable as any of my modern cars.
I am about 3/4 of the way through converting my euro high compression 350sl (116 engine) over to MS. for that I am going MS2 and EDIS. its just been slow due to time constraints but should be done for summer. I will try to post updates as i go.
with the current downturn in the economy I am spending a lot more time in work and traveling a lot more so tend not to check the forums as much my email is in my contact details but I may be slow to respond. I am a big fan of MS and happy to try and answer any questions if I can and will try and update my websites with the latest VE tables and settings.
good luck with it
Barri

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61 Austin mini
67 Lotus 7
74 450sl
76 Cadillac 8.2l (501 ci)

some new cars

megasquirt conversion on:
djet 74 450sl http://www.mercdjetmegasquirt.britautorepair.com/
cis 76 450sl http://www.merccismegasquirt.britautorepair.com/

the best view is always from the point of no return

Nice to get barri's update!

Alistair asked me off-line about the capacity of the Bosch D-Jet injectors (which vary depending on which site you go to!)

I found this on a Bosch Site. It is in German and seems to take into account the 2bar pressure the D-Jets use:

http://www.automotive-tradition.de/download/kennlisten/elektrik/magnetventile/0280150.pdf

The 4,5L injectors are 02801500036 and 3.5L 02801500034

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Graham
85 300D,72 350SL, 98 E320, Outback 2.5

I remember reading a while back you were converting your M116 to EDIS. Not sure if you resolved the trigger wheel construction but here is what I have done. I had this wheel custom machined for a interference fit over the crank pulley+ I will use some hi-temp RTV to hold it to the harmonic balancer for extra piece of mind. No permanet mods to the engine. I will create the mount for the VR sensor once the engine is in the car and I can see what is in the way. This wheel was less than $40 and I can give you the details on where to get it if you PM me.

Attached Thumbnails

 

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Tony H
W111 280SE 3.5 Coupe
Manual transmission

Past cars:
Porsche 914 2.0
'64 Jaguar XKE Roadster
'57 Oval Window VW
'71 Toyota Hilux Pickup Truck-Dad bought new
'73 Toyota Celica GT

Gi'day all - Alastair from Adelaide, South Australia here. My modest project is to MS my 1971 280 SE 3.5 (fuel only at this stage) With the generous assistance of Guru Barri and others (thanks guys ) this is proving to be slow but relatively straightforward and I will write the whole experience up when I get the car running. As far as I know, it will be the first M116 with Megasquirt in Oz. I'd be happy to be proved wrong on that so if you are out there.....
The TPS has been replaced with a SAAB part, and a narrow band O2 sensor welded into one of the exhaust pipes. Apart from that I'm using all the original sensors, and injectors. I've soldered up a replacement loom as I hope to mothball the original.
I'm getting a lot out of these discussions. Regards
Alastair

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Alastair from South Australia
1971 280 SE 3.5
1981 300D
1980 300D

What was the Saab TPS part number? I've modified a Ford TPS to fit but I'm not happy with the looks of it.

Saab TPS is Bosch p/n 0 280 122 001. I got mine on Ebay. Here is one: http://cgi.ebay.com/ebaymotors/1995-Saab-900S-TPS-Pt-0-280-122-001-OEM-A23_W0QQitemZ260541789936QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item3ca98036f0
I modified the back plate of the D-jet TPS. See picture here: EFI vs CIS

It helps if you get the associated SAAB TPS three wire output plug as well, often sold separately.
Alastair

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Alastair from South Australia
1971 280 SE 3.5
1981 300D
1980 300D