any thoughts?

First, we will need to know more about your engine, how you plan to use it and your ability to tune the system. I am going MS on my 2056 build because I want more flexibility over the long run. But I know that I need to be patient in tuning MS correctly.

Although I have done it, I think it best to think of the D-jet as non-adjustable. It wasn't meant to be fiddled with and its strong suit is that it seems very well matched to the needs of the stock engine. It produces an analog map that I find remarkable. When clean and in good repair with all the hoses and proper engine timing I find D-Jet very good. But you will never be able to hook it up to your laptop.

MegaSquirt if you like searching for components, troubleshooting, and learning new things. It's a great and flexible system. I drive mine every day. But it's a steep learning curve and if you're not ready for it, it can completely stall your project while you get up to speed. Troubleshooting is more difficult because the combination of parts you use is often unique, so no one else has your exact setup. Parts are difficult because for each component it's up to you to pick one that will work with this engine.

D-Jet is much simpler. So troubleshooting is easier because you can ask everyone here. Parts are easier because you know exactly what you need to buy when something goes wrong.

The upside of MegaSquirt is tuneability. If you don't need that (stock engine for example), then use D-Jet.
The downside of MegaSquirt if complexity, especially during the installation and tuning phase.

The upside of D-Jet is simplicity.
The downside of D-Jet can be part availability and/or cost of parts. If you already have a working system or can find a known good system for sale, then use D-Jet. But if you have no parts, or if you know a lot of them are bad, it may be cheaper to go MegaSquirt.


And finally, look into MicroSquirt. It's cheaper, smaller, sealed from the weather, and does everything our engine's need.

I'm throwing Djet as far as I can, no idea trying to keep an old system alive when the new ones are so much more versatile and efficient.

If Djet runs and works, then dont mess with it, once it starts to malfunction I'd take that as an excuse to upgrade. MS isn't easy tho and you WILL HAVE TO READ AND RESEARCH ALOT to make it work.

The engine is a newly built 2056, runs great when the D-Jet worked. That did not last long, I've spent several days going through all the components again, checked the valve lash (0.00 Chromoly pushrods) Jake's 9590 Cam, Stock ignition at this point just stock D-Jet components.

I just reset the TPS and that resolved the last issue for about four hours then another issue has come along.

How do I plan on using the car? it is my wife's 914, I plan on saying "see you in a little while dear". And not having to call the flatbed tow truck every time she leaves.

After my latest battle with the car, these are my own thoughts exactly.

As long as you're up for the learning curve. I can't overstress that part. D-Jet may seem like a PITA, but at least there is help available. MegaSquirt is like heading off into the woods with a hand drawn map. Maybe you'll get right to where you're going. Maybe you'll get lost along the way and it'll take three times longer than it should.

As long as you're ready for that, jump in!

I was going to ask if you are going for originality or a good driver, but I think you answered my question. For ease of problem diagnosis on a driver, Megasquirt is the way to go. Also the way to go for ease of finding parts, ability to customize, and performance.

My biggest issue with the D-Jet is that once you troubleshoot a component that is having issues, then you can't find a known good one. The MPS for example, the ECU for another. I completely rebuilt the harness for the FI, I resealed the relay board and tested all the circuits for it. When everything else finally started working together and the car drove well. The brand new Head temp sensor took a dive. This car was going to be a few month rebuild that I was fitting in between two other cars. a year and a half later. (I did have to develop a really good line bore system for the Type IV in house, that took a little bit of time.) Now a third car is moving into the mix, and this car just won't drive.

Sorry for the rant,

It is certainly your call on D-Jet vs. megasquirt.

Can you describe the current issue you are having?

Djet can handle a 2.4 liter motor.
Idle will be tricky with that camshaft, but it can be made to work.


I have a question about mega squirt.
How do you measure air flow, and how much lift and overlap can you get away with?

Air flow can be measured a few different ways, but MAP is common.
Dragsters with huge lumpy cams use MS. The question isn't where is the limit, but more how much do you want to tune and play with it to get it to work.

Zach

Not really, the current issue is that the car drives fine, I park it for a couple hours or a day, then it has a new different problem. My next step is to investigate the ECU by throwing different units at it and see if the problem changes. I've pretty much eliminated all else at this point. using the Rennlist P.B. Anders, Factory manuals and other troubleshooting guides. I'm a pretty tenacious guy.

Have you replaced the wiring harness for the fuel injection?

It's the cam Jake's guy suggested for D-Jet, and actually for the first several days the car idled just fine with the D-Jet. To be exact the car still idles just fine, you just can't drive it with load on it..............Sometimes... So I don't believe it is cam related. A cam compatibility issue would have had surfaced in the beginning. The plugs are sooty rich at times and super clean at others. Ignition is not cutting out.

Yes, The harness has been completely rebuilt and tested.

I'm a huge MS fan. With D-jet you are stuck with a stock or just off stock cam. MS you can run anything and have a motor any size.

Basically you can look at the two systems like this:

With D-jet you must plan your motor around the injection system.
With MS you build your motor and tune the injection system to run it.

With all the info out there and with all the people running MS these days, it's easy to find someone with a similar motor that will send you their MSQ file (the tune). From there, you can fine tune it to your particular motor.

Much of the problems that folks have when setting up MS (me included) is not getting the correct basic parameters entered in the initial drop down menues. The tuning of the VE and timing tables is not too hard especially with the advent of autotune mode. Autotune mode will get you close and make it very drivable. The rest is simply playing with it and refining your tune under various conditions.

With MS, you can adjust everything and it makes carbs and distributors obsolete in a hurry.

Well, I will give you the short list.

New wiring harness
New FI trigger points
New cht
Remove AAR
Unplug cold start injector
Re route fuel line around cold start injector ( they leak or dribble randomly)
Lose the decel valve

Plug all the open ports on the plenum.
Should have one hose to the plenum if done right ( I forgot a few items)
One hose goes to the MPS
All other hoses are unplugged and capped at the plenum.

Drive the car.

Now you are running on a very simple functional system.
Add in each individual unit one at a time, drive the car afterwards.

I had idle issues.
It was a combination of injector seals, timing and the TPS that i had changed to mask the vacuum leak. Put the new seals in, reset timing and Tps, all is well.
Tps has only one correct setting, it's not adjustable..just needs to be set right and forget it.

I had stumble issues.
Turned out to be distributor advance plates were dirty, cleaned and regressed for a nickle, car ran perfect.

I have had other issues, replaced if trigger points, fixed it.

Mps is easy to test...

You can set it up using MAP or Throttle Position (Alpha-N) or MAF. You can also blend airflow vs. throttle position, so use throttle position down low where the vacuum is lumpy, then switch to MAP/MAF as RPM increases.

91 posts on this board is not nearly enough to get your car running properly.
Heck, tuning djet is worth at least 150 posts alone...

Then tires and wheels could easily stack up to 50 posts, every three years, more frequent if racing.

Wiring, especially LED lighting, could generate at least another hundred....

Zen and the art of engine tuning. If you're more interested in the destination than the journey, I wouldn't go with megasquirt unless you're already a pro with it, in which case you probably wouldn't have posted the question. If you're more interested in the journey than the destination, then megasquirt away. My $0.02 worth anyway.

You forgot about oil choice!

Happiness is a choice not a goal.

To me life is all about the journey, Once your at the destination then it's time to go somewhere else.

Sounds like you answered your own question. I'll be interested to hear how your Megasquirt experience went because i am looking at that vs. LH-Jet (from 1980's Volvo/Saab) on a future 2270 build.

Jesco,

I was in the very same position you're in now when I went to megasquirt. Had several issues that couldn't be resolved with static testing of components. My whole megasquirt II setup was $350 complete - though that was 6-7 years ago. I never regreted it. Once I hooked up my computer and could see in real-time various sensor feedback I was able to solve all the issues. One was a head temp sensor that would intermittently drop out. Never showed up during a cold or hot test - but did seeing the real-time readout with MS.

McMark is right though you gotta be willing to pursue some things. You can do a lot of tuning on the street but nothing beats an hour or so on a dyno. It will be the best money you spend on the project.

Good luck. Do a search for my articles on megasquirt - got my whole configuration listed on here somewhere.