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914World.com _ 914World Garage _ 1.7 Vs. 2.0 D-jet
Posted by: Bob L. Mar 12 2012, 06:44 PM
I'm guessing the injectors would have to be swapped out but are there any problems adapting it?
Thanks.
Posted by: Dave_Darling Mar 12 2012, 09:00 PM
Different part numbers for a lot of parts. For 73, the ECU is the same, but the 70-72 1.7 has a different ECU and the 74+ 2.0 is also different. The MPS is calibrated differently. The head temp sensor is different for the 1.7, 73 2.0, and 74+ 2.0. The injectors are different. The FI wiring harness is different because the components are in somewhat different locations.
http://members.rennlist.com/pbanders
Brad Anders has a list of the part numbers from the various years. You can see the differences there.
--DD
Posted by: brant Mar 12 2012, 09:09 PM
the throttle bodies are larger/smaller
the TPS is different
the intake runners and plenum are larger/smaller
the distributor is different
nearly everything is different
all of the 2.0 stuff is slightly bigger and flows slightly more to accomodate the larger displacement
Posted by: Bob L. Mar 12 2012, 09:56 PM
Okay then. So basically not a swap candidate.
Someone suggested using a throttle body injection setup from the center. Anyone tried that?
It seems that there would be the same potential for icing or fuel falling out of suspension. Right?
Posted by: rdauenhauer Mar 12 2012, 10:22 PM
You can do it.
Will it run optimally... probably not.
But nothing that with enough ingenuity you cant tune around.
If you could get a complete FI "kit" off of a 2.0L the only real obstacle or Mod you would have to deal with is the 3-4 bolt intake mounting.
ideally if you bumped your displacement with a set of P&C's to 1911 youd be back in the mix.
Posted by: vsg914 Mar 13 2012, 06:43 AM
If the 1.7 is stock you will have probably have problems by switching to the 2.0 system. I had a customers 1.7 bumped to the 1911 cc that we just could not make it run right. I changed the plenum, throttle body, tps, injectors, and air filter to the 2.0. The 1.7 intake runners had to be cut down to fit, and the connection for ts-1 had to be lengthened. It really woke the engine up.
Posted by: underthetire Mar 13 2012, 08:41 AM
Okay then. So basically not a swap candidate.
Someone suggested using a throttle body injection setup from the center. Anyone tried that?
It seems that there would be the same potential for icing or fuel falling out of suspension. Right?
Like an old chevy "electronic carburetor" throttle body? Seems like a total waste of time, since you would have to build the intake set up any way, just use 1.8/2.0 runners and a air only throttle body off a honda or something. At least you could still use port injectors.
Posted by: Prospectfarms Mar 13 2012, 09:17 AM
If your looking for ideas to fuel a bigger motor, explore root_werks thread on "L-jet for 2.0" 
BTW, thanks for this short but "meaty" thread with lots of good info/experience.
Posted by: Bob L. Mar 13 2012, 09:38 AM
I'm glad my ignorance can help others. 
I'm not really looking for a bigger motor. I just want this one to run for a while so I can do a rolling resto and then look into improving power.
If anybody knows where a complete 1.7 D-jet set can be had, I'm all ears.
Posted by: Prospectfarms Mar 13 2012, 09:46 AM
For what its worth, those guys, root_werks, etc also converted a 1.7 to L-jet. Didn't sound hard, and they liked it. 
Posted by: underthetire Mar 13 2012, 09:52 AM
I will add that since 2.0 Djet parts are getting almost impossible to get now, and 1.7 not much easier, was the main reason i went megasquirt. It allows you to be able to change/update any component in the FI system and program around it. It can be done very cheap compared to good/new replacement parts. I think I had ~300 in the entire system. (using stock injectors/runners/throttle body)
Posted by: Bob L. Mar 13 2012, 10:44 AM
I will add that since 2.0 Djet parts are getting almost impossible to get now, and 1.7 not much easier, was the main reason i went megasquirt. It allows you to be able to change/update any component in the FI system and program around it. It can be done very cheap compared to good/new replacement parts. I think I had ~300 in the entire system. (using stock injectors/runners/throttle body)
$300. is not bad at all. What did you start with?
I have no FI parts now. What would I need from the old system and what new?
I assume It'll be more $ for me since I need runners and some other stuff.
I have read a few threads about mega/micro squirt. I just can't get a sense of the actual costs involved. I think Micro would be fine for me.
I like the idea of keeping the FI and modernizing it as well.
Has anyone done a simple microsquirt conversion on a 1.7?
Honestly, what's the realistic price range?
Posted by: underthetire Mar 13 2012, 11:11 AM
Can you solder? do you have patience?
Here is a list of what i used, some is optional.
Megasquirt DIY kit. (you solder the board together, its quite easy and takes ~6 hours) ~250
O2 sensor, I used a heated one since my O2 is in the header collector. ~30
Throttle position sensor-this is actually optional, I got a GM one to fit ~30
No relay board, since the 914 has a ground operated relay for the fuel pump already
Misc wire, or you can buy the labeled harness from DIY autotune. free to ~50
You will also need an RS232 cable for a laptop, and of coarse a laptop. Anything will work.
You will need to find the intake runners, injectors, fuel rails, throttle body. AAR is optional, and the fuel pump. I used a cheapy 2 port pump from a BMW application, it was ~60 bucks after my stock one gave up.
Total time from start of kit to first engine start was ~ 3 days. Lots of tuning afterwards.
It's worth downloading the free manual and learning all you can first. I did not use the Stim kit.
And remember, you can get a lot of stuff from Pick N Pull that really helps for dirt cheap.
Posted by: JawjaPorsche Mar 13 2012, 11:23 AM
Try Jim Kelley on this forum. He usually has a lot of the parts you need for a D-Jet.
Terry
Posted by: ChrisNPDrider Mar 13 2012, 01:33 PM
I luv my stock 1.7 D-jet; reliable and freeway cruisin at 30-35 mpg.
If I were you, I would do my best to stay w a stock, proven combo and spend the time to get a complete system off a running motor. OR, spend a little extra $$ and buy from EASY or Parts Heaven with a (hopefully) 90-day warranty. Buy it when you have time to immediately install and test it to get the most of the warranty.
I have been slowly improving my "cafe racer 914" for 5 years while I save $$/research a new engine. The rolling rustoration is a good place to be 
Posted by: vsg914 Mar 13 2012, 06:08 PM
Well shoot! I thought you were going from a1.7 to a 2.0. I have lots of 1.7 stuff. Didnt think anyone wanted it.
Posted by: Bob L. Mar 13 2012, 10:08 PM
Well shoot! I thought you were going from a1.7 to a 2.0. I have lots of 1.7 stuff. Didnt think anyone wanted it.
Nope, Just saw a set for sale and thought...
Is yours '73?
Posted by: Bob L. Mar 17 2012, 12:04 AM
Can you solder? do you have patience?
Here is a list of what i used, some is optional.
Megasquirt DIY kit. (you solder the board together, its quite easy and takes ~6 hours) ~250
O2 sensor, I used a heated one since my O2 is in the header collector. ~30
Throttle position sensor-this is actually optional, I got a GM one to fit ~30
No relay board, since the 914 has a ground operated relay for the fuel pump already
Misc wire, or you can buy the labeled harness from DIY autotune. free to ~50
You will also need an RS232 cable for a laptop, and of coarse a laptop. Anything will work.
You will need to find the intake runners, injectors, fuel rails, throttle body. AAR is optional, and the fuel pump. I used a cheapy 2 port pump from a BMW application, it was ~60 bucks after my stock one gave up.
Total time from start of kit to first engine start was ~ 3 days. Lots of tuning afterwards.
It's worth downloading the free manual and learning all you can first. I did not use the Stim kit.
And remember, you can get a lot of stuff from Pick N Pull that really helps for dirt cheap.
Yeah, I can solder. I've seen The Microsquirt units on e-bay. They look ready to go with an 8 " harness for about $350. shipped.
How do you get around the TPS?
Tell/show me more please.
Posted by: underthetire Mar 17 2012, 12:19 AM
Megasquirt has a built in map sensor. You can set it up to not use the tps, just map for accel, or tps, or a combination of both, or even a mas airflow.
Lots of good info in the manual, even if your not going to use a megasquirt, it starts with the basics of fuel injection.
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