i am setting up my d-jet to operate the new 2056, it origanally was 1.7. i need some experianced input on running either a "modified perameter" 1.7 or 2.0 m.p.s. which of these 2 combo.s would work the best?:

1) a modified 1.7 (max. re-calibrated setting for 2.0) with increased fuel press.
(note) higher fuel pressure increases atomazation so this combo may have benifit over #2?
PROS: i could re-calibrate/use my good 1.7 M.P.S.,
CONS: have to adjust a/f with increased fuel press. at regulator and set on a/f scope

2) a modified 2.0 (able to set to 2056 fuel requirements)
PROS:? keep stock fuel pressure
CONS: have to locate/buy or trade a good 2.0 m.p.s. for re-calibrate

answers to the below questions will be helpful in desiding how to go

i'm trying to understand if the m.p.s. operation, does it have a profound (dont know if thats exactly the word i'm looking for) effect on the e.c.m.'s output for the full range of f.i. operation?

would programing a 1.7 to 2.0 a/f settings + raised fuel injection press. do the same (or better?) than a reprogrammed 2.0 m.p.s. set to 2056 a/f calibration? when you re-program the m.p.s. what data exactly does it input to the computor? manifold pressure and?? is it very basic data or does it relay more complex values and ranges?

if i go route #2 DOES ANYONE HAVE A 2.0 M.P.S. 4 SALE OR PARTS SWAP?

thanks, mike

EDIT NOTE:
new info. from p.m.
so it's basic duty is the same as a modern map sensor. if i adjusted fuel pressure higher it could find the balance a/f ratio by 1) increased pulse width (max. setting,) plus- 2) incress fuel pressure to fine tune a/f ratio across the board since m.p.s. is handling the three parameters.

You should probably review Brad Anders webpage Mike...

http://members.rennlist.com/pbanders/manif...sure_sensor.htm

Use the 2.0 liter ECU and re-calibrate any MPS, 1.7 or 2.0 that you know is good.

Geoff in Seattle offers this service and he also has a 2056, so he will know exactly how to tune it, and will probably run it on his personal car with a A/F meter to set it up.

Rich

Screen Name Blyseng....he did mine.

according to the d-jet info my 73's ecu was used for both 1.7 and 2.0 (different m.p.s., cht with resister)so i think i'm good there

do you know if geoff has been able to set a 1.7 to meet 2056 requirements? from what i know they wont adjust enough where a 2.0 (039) will. am i wrong? have others sucessfully done a 2056 off of a 1.7 m.p.s.?

mike

ASK GEOFF

dan, which m.p.s. did you have set? what other items did you have to deal with? did you scope acual a/f through the ranges?

mike

thanks, will do

sent my original '74 2.0L mps to Geoff, he takes it apart, cleans things up a bit and then sets some stuff internally...static...then puts it on his car and makes the final adjustments....at least I believe that is the sequence.
after I got it back put it on the motor and she started right up and has run without a glitch ever since. that was last April. ~10 AXs and 3 track days at Laguna.
not one hiccup. Drove the car to several of the AXs at Candlestick and Marina... Plus I drive it in town ~1x per week...weather permitting...no heater.

Using a 73 1.7/2.0 ECU causes some problems tuning but I can do it IF I have the proper MPS with enough range to "tune" with. I actually like early 1.7 ones with a late style cover. These have the most range so I can get the AFR right from idle to WOT. Most MPS's can't get enough richness at WOT if you are running a 2056 w/a RAby 9550cam.
Look at the MPS pic in my Blog to see the cover insides....
The best MPS for a 2056 Raby Cam engine with a 73 ECU is of course the 037. Lots of range to tune with....

I have tested the idea of tuning with the FPR and you can tune it about .5 of richness meaning if you AFR is 14 to 1 you can tune to 13.5 to 1 upping the pressure to 36psi.
You must use a LM meter to tune or you are wasting your time...especially on the MPS as very small turns of the inner screw can result in changes of 1 point.

If you have a good diaphram I can make a MPS for a 2056. I just have very few good diaphrams left and I don't use those rebuilts available now.

i have the 73 ecu, i also have a 72 1.7 ecu in unknown condition (probably is useless here anyway). yes 2056/ raby 9550 cam. do you know of a 037 m.p.s. for sale or trade? i have a 72 m.p.s. also i'll research your blog, do you mean you use late 2.0 style covers with early?

if it doesnt quit make 13.5:1, whats the worst you've experianced getting a 1.7 m.p.s. a/f ratio up to? (i.e. 15:1, 16:1?) have you experimented with higher f.p.? any benifit from better atomazation?

thanks for all the info., mike

I haven't been able to make a 1.7L MPS work or adjust to work on a 2056 w/9550 cam.
It did run at about 16 to1 way too lean and bucked when I drove with it.

Max FP with these early 2.0L injectors is 36psi as the weak springs then cause them to shoot a stream instead of a cone spray...not too good for atomization.