FI retrofit, it's done!!! Options

[toon1]

I've been working on retrofitting newer fuel injectors for the 914. My goal was to find an injector that can utilize as many of the stock parts as possible.

I came up with a inj. off a 96 forn escort 1.8l motor.

One comment is needed, this will only work with an aftermarket FI system s these inj. are HIGH inpedence.

This setup gives the ability to use higher fuel pressure, 44psi . It has a lower flow rate than the stock inj.. so the pulse widths will be longer and should give a little better idle quality.

these are disc style rather than pintle( stock). fuel atomization will be much better giving a cleaner, more efficiant burn.

The length of the inj. where shorter than stock so I added an O ring to make up the difference.

The plastic tips are different ,I cut them off and put the tip of the stock inj. on the new inj., fit perfect. now the stock tip O ring can be used.

the fuel rail was machined to tolerance for the top O ring seal. And I made a bracket to support the fuel rail from vibration and also keeping it from popping off the top of the inj.

Here's the setup assembled. enjoy

[toon1]

I did some calculations with the ford escort inj. and determined they were a bit too small.

After running the calcs., I did some work with MS on stim and
With the flow rates of that inj., the duty cycle at WOT. was about 115%.

The FP would have had to been run at about 55psi to get the flow rate for 85% at WOT.
I had a set of four inj. from a ford probe INP480's. The flow rate was hard to find but it flowed about 21lbs/hr, about the same as the stock inj. but at 43psi.

After running those #'s on MS and the stim, it looked good. I had pw's at idle around 2.2ms.

these will also give the latatude to lower the FP, if needed and not hurt the fuel atomization.

The probe inj's had a smaller top so I made some new rails with smaller holes. otherwise everything else fit the same as the escort inj's.

The connectors where no prob., I just cut them off the wire harness of the probe.
they fit just fine with the inj's. in the rails.

I have not put them on the wire harness yet but will soon.

with the inj's. on the air intake runners which are installed on the motor, it all looks good (IMG:style_emoticons/default/biggrin.gif)

I am also retrofitting an EDIS system to the motor,direct coil drive so I have to add a 2nd coil driver.

The engine parts took forever to get back from the machinest(4months!).

Right now the engine is built and close to being ready for install. Unfortunatly I have run into probs. with my truck. The tranny had to be replaced and also the intake man. gaskets so it has be occupiing my time for the past few day's

The car is still a way's off from running but I am anxious to get it going.

Keith

[yarin]

I did some calculations with the ford escort inj. and determined they were a bit too small.

After running the calcs., I did some work with MS on stim and
With the flow rates of that inj., the duty cycle at WOT. was about 115%.

The FP would have had to been run at about 55psi to get the flow rate for 85% at WOT.
I had a set of four inj. from a ford probe INP480's. The flow rate was hard to find but it flowed about 21lbs/hr, about the same as the stock inj. but at 43psi.

After running those #'s on MS and the stim, it looked good. I had pw's at idle around 2.2ms.

these will also give the latatude to lower the FP, if needed and not hurt the fuel atomization.

The probe inj's had a smaller top so I made some new rails with smaller holes. otherwise everything else fit the same as the escort inj's.




Keith

Hey Keith,

What were the flow #s for the Ford Escort injectors that you determined were too low? (15-16 lbs/hr?)

Stock injectors flow:
Yellow (1.7L) - 265 cc/min (25.2 lbs/hr) @ 2.0 Bar
Green (2.0L) - 380 cc/min (36.1 lbs/hr) @ 2.0 Bar

The theoretical mechanical limitations of most injectors to open/close are about 1.7ms from what I've read. So in your case PWs of 2.2ms are great and leave with you plenty of room to play. May I ask how you arrived at 2.2ms?

Looking at my datalogs I see that at idle my PWs are 1.3-1.4ms, I never really analyzed this but this is a problem since the injectors are limited to 1.7ms. Correct? Should I change # of squirts to 2 instead of 4 (double req calc req fuel from 4.2 to 8.4ms) will yield PW of 1.77ms.

The equation is PW = REQ_FUEL * VE * MAP * E + accel + Injector_open_time
If I do the calcs manually I should get 4.2ms * 30% x (29 / 100 kpa) + 1.0ms = 1.36ms which is what i see in my datalogs.

In addition, with the Green 2.0L injectors my max situations are as follows:
WOT @ 5000-5500 rpm, PW ~4.2ms, Duty cycle 39%, AFR is really rich at around 11.6. I can send my datalog for anyone that is interested. This just illustrates that these injectors are WAY oversized as previously mentioned.

I'm looking at this Injector flow table trying to figure out which injectors I want to go with: http://users.erols.com/srweiss/tableifc.htm I want to go with high impedence so I can move away from PWM. Any suggestions?

I found some more info on your Ford Probe injectors here: http://www.fuelinjector.citymaker.com/page/page/5129028.htm
1993-97 application. Here is a set on ebay. Too $$ though. I'd rather buy a used set and send them off to cruzin performance.

I'll keep an eye out for ~21-22lb injectors cross referenced between This site for flow data and This site for application then check ebay periodically.

Any tips would be most appreciated, also I haven't looked at MS fuel requirements and PW in over a year so i might be a little rusty.

Thanks@