MPS adjustments for a 2056cc w/Raby cam Options

[Bleyseng]

I finally have gotten the MPS for 2056 with the Raby 9550 cam adjusted right. Blair and I got a LM1 meter and tuned it using my laptop and driving around for load testing, then jumping out to minutely adjust the MPS to set the A/F. Took awhile but it is amazing to drive the car and change the A/F setting a tiny hair of a turn to go from 12.5 to 13.5 to 1. Wow, the MPS diapharam setting are that delicate but I was able to set the cruise, idle and WOT and the car runs super sweet now. Tons of power all thru the rpm range until 6200 where I stop. I haven't noticed the high rpm lean out others have reported as the WOT and cruise A/F stay stable until 6200 rpms right where I set them up.

Basically, a short cut would be to use a 037 MPS thats factory calibrated as that is very close to where I ended up, maybe a hair lean.

Using a Wavetek my baseline reading are for my tuned MPS:
15hg- .78
4hg-1.32
0hg- 1.58

Compared to my readings of a 037 OEM MPS:
.15hg-.75
4hg-1.27
0hg-1.53

I set my A/F ratios to 12.5 to 1 at WOT, 13.6 to 1 at cruise and idle.

Using the 9550 cam, HD valve springs, and the bigger exhaust valves (38mm) demand more fuel over a stock MPS. I have installed a NOS 043 MPS and it runs ok but the A/F reading are closer to 14 to 1 and hesitates instead of taking off smoothly. Dropping down to 13.6 to 1 on cruise really smooths the engine out and you have to set the WOT at 12.5 to 1 to get the power and smooth run up the rpms scale.

Blair and I will be playing with this more just to see what all more we can figure out or damage... I can see where the programmable EFI would really be fun. This is old school but it again proved that the Djet is fairly tuneable and adjustable to modified engines.

(IMG:http://www.914world.com/bbs2/html/emoticons/burnout.gif)

[Frank S]

Hi guys,

I'm new here and have received my 2.0 1973 D-Jet 914 from California in January. At present the body is for paint removal and repainting in the body shop and I'm just about to take care for the engine.

I want to use a 9590 cam with 2056cc and stay original with the rest.

Since you have some expirience with that setup (9550 cam which is not so different).
I would like to ask at which CR you are running?
I don't want to overheat the engine and planning for CR 8.0 or max 8.2.
How does your engine idle and at what RPM.
What other work than the MPS tuning was required to make it run smooth?

Thanks,
Frank

Frank S, I don't have an answer about CR for your engine, but

(IMG:style_emoticons/default/welcome.png)

You should start an intro thread with pictures! (IMG:style_emoticons/default/beer.gif)

Thanks for welcoming me, I'll start a new thread with pics as soon I've a bid more time, no good pics available jet.
Cheers,
Frank

[Frank S]

Hi guys,

I'm new here and have received my 2.0 1973 D-Jet 914 from California in January. At present the body is for paint removal and repainting in the body shop and I'm just about to take care for the engine.

I want to use a 9590 cam with 2056cc and stay original with the rest.

Since you have some expirience with that setup (9550 cam which is not so different).
I would like to ask at which CR you are running?
I don't want to overheat the engine and planning for CR 8.0 or max 8.2.
How does your engine idle and at what RPM.
What other work than the MPS tuning was required to make it run smooth?

Thanks,
Frank

I am running 9 to 1 CR and it never overheats but I also run Premium gas.
I set the idle at 1050-1100 rpm set when the engine is hot.
tuning the MPS made it run smooth along with having the injectors cleaned.
On a 1973 using the stock 039 ECU you have to run the 017 CHT to get a good idle.

Hi Geoff,

thanks for sharing the data with me, in that case I would go also to higher CR with a max of 9 to 1.

It is a 037 ECU with a 043 MPS which came with the car I don't know if this is the original set-up (car was build in 10.1973) but the whole engine looks pretty much untouched accept the air flaps which have been blocked in open position.

I'm just about to list all part numbers to check if the setup will work proper.

Cheers,
Frank

[worn]

At 60 mph you may to still be in fourth gear and not be lugging the motor in fifth with the fan speed lower.

Yeah, but on a road trip that can be a bit, well irritating. The sound gets on my nerves because I was brought up shifting early for economy and lower wear. Also, I haven't been able to get a lot of cooling by downshifting anyway. Tried it. First task of the thaw is sorting out (again) MPS tuning. Now that I have drivability I will be looking for correct mixtures across the board. I will probably use a human data logger.

[Bleyseng]

Hi guys,

I'm new here and have received my 2.0 1973 D-Jet 914 from California in January. At present the body is for paint removal and repainting in the body shop and I'm just about to take care for the engine.

I want to use a 9590 cam with 2056cc and stay original with the rest.

Since you have some expirience with that setup (9550 cam which is not so different).
I would like to ask at which CR you are running?
I don't want to overheat the engine and planning for CR 8.0 or max 8.2.
How does your engine idle and at what RPM.
What other work than the MPS tuning was required to make it run smooth?

Thanks,
Frank

I am running 9 to 1 CR and it never overheats but I also run Premium gas.
I set the idle at 1050-1100 rpm set when the engine is hot.
tuning the MPS made it run smooth along with having the injectors cleaned.
On a 1973 using the stock 039 ECU you have to run the 017 CHT to get a good idle.

Hi Geoff,

thanks for sharing the data with me, in that case I would go also to higher CR with a max of 9 to 1.

It is a 037 ECU with a 043 MPS which came with the car I don't know if this is the original set-up (car was build in 10.1973) but the whole engine looks pretty much untouched accept the air flaps which have been blocked in open position.

I'm just about to list all part numbers to check if the setup will work proper.

Cheers,
Frank

You should have a 037 MPS on that 73 2.0 as the 043 is too lean unless someone has adjusted it. With a 9590 cam you will have to adjust it to the correct AFR.
If you send it to me I can get it pretty close.

[Phoenix914]

You should have a 037 MPS on that 73 2.0 as the 043 is too lean unless someone has adjusted it. With a 9590 cam you will have to adjust it to the correct AFR.
If you send it to me I can get it pretty close.

I have the same ECU/MPS combination as Frank S with my 2056. I also have a -012 CHT, rather than the -017 that is NLA. I'm wondering if one or more of these components should be swapped out? Geoff, you said you can get the MPS pretty close. Is it worth the trouble, or just try to find the correct one?

[914_teener]

FWIW.....

I have a CHT that ohms out to the -17 specs on the Anders site.

McMark made it from a core I had sent to him. Just getting ready to test it this weekend.

It has a separate ground.

I think it would be well worth sending your MPS to Geoff so you at least know what your baseline setting is....slap it on your car and tune it from there.

[Bleyseng]

You should have a 037 MPS on that 73 2.0 as the 043 is too lean unless someone has adjusted it. With a 9590 cam you will have to adjust it to the correct AFR.
If you send it to me I can get it pretty close.

I have the same ECU/MPS combination as Frank S with my 2056. I also have a -012 CHT, rather than the -017 that is NLA. I'm wondering if one or more of these components should be swapped out? Geoff, you said you can get the MPS pretty close. Is it worth the trouble, or just try to find the correct one?

For a 73 setup I have to reinstall a 73 2.0L setup including the 017 CHT and then tune the MPS. It's way different than a stock 043 setup or a 043 setup for a 2056 rabycam.

[MichaelB]

I finally have gotten the MPS for 2056 with the Raby 9550 cam adjusted right. Blair and I got a LM1 meter and tuned it using my laptop and driving around for load testing, then jumping out to minutely adjust the MPS to set the A/F. Took awhile but it is amazing to drive the car and change the A/F setting a tiny hair of a turn to go from 12.5 to 13.5 to 1. Wow, the MPS diapharam setting are that delicate but I was able to set the cruise, idle and WOT and the car runs super sweet now. Tons of power all thru the rpm range until 6200 where I stop. I haven't noticed the high rpm lean out others have reported as the WOT and cruise A/F stay stable until 6200 rpms right where I set them up.

Basically, a short cut would be to use a 037 MPS thats factory calibrated as that is very close to where I ended up, maybe a hair lean.

Using a Wavetek my baseline reading are for my tuned MPS:
15hg- .78
4hg-1.32
0hg- 1.58

Compared to my readings of a 037 OEM MPS:
.15hg-.75
4hg-1.27
0hg-1.53

I set my A/F ratios to 12.5 to 1 at WOT, 13.6 to 1 at cruise and idle.

Using the 9550 cam, HD valve springs, and the bigger exhaust valves (38mm) demand more fuel over a stock MPS. I have installed a NOS 043 MPS and it runs ok but the A/F reading are closer to 14 to 1 and hesitates instead of taking off smoothly. Dropping down to 13.6 to 1 on cruise really smooths the engine out and you have to set the WOT at 12.5 to 1 to get the power and smooth run up the rpms scale.

Blair and I will be playing with this more just to see what all more we can figure out or damage... I can see where the programmable EFI would really be fun. This is old school but it again proved that the Djet is fairly tuneable and adjustable to modified engines.

<!-- emo&:burnout: -->(IMG:http://www.914world.com/bbs2/html/emoticons/burnout.gif)<!-- endemo -->

Hi, I'm still playing with the timing and the MPS on my 2056, how much advance did you engine end up liking? 28 degrees at 3500?

[Bleyseng]

I set mine at 27 degrees BTDC hoses off and plugged as I use the vacuum adv off the throttle body.