EFI upgrade of k-jetronic on GTSi

I've done 1/2 dozen QV conversions over the years......it's not all that difficult.

 

It all depends on your level of experience. None of it very difficult. But you will need to develop fuel and timing curves as well as the cold start and many other perimeters.
I had to modify the intake runners to handle electronic injectors. You will need a crank sensor. I used the stock sensor and added pins to the flywheel. You may need a cam position sensor. It doesn’t necessarily need separate ignition box’s. My ecu fires 8 individual LS coils and can use stock sensors (Motec) other ECUs may have different capabilities.
Good luck. Btw. I found it VERY helpful to select an ecu that has logging capabilities to really fine tune your engine.

 

I'm working on a complete efi conversion system for my 308QV using one of the link ECU systems and I plan to start a thread soonest. My goal is to make a completely reversible installation that appears as close as possible to the original engine room design. I will make no significant modifications to the original components and the throttle body and air intake will remain as original - Though I'm planning for a light tune of the engine with high compr. pistons and new cams. Here is a few preliminary pictures for inspiration. Note that the project is hobby based, it's my first efi project and I'm already surprised over the scope of work I have in front of me having to custom fit every little detail. Looking forward to follow your project "Andy..."

Best, Peter


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Yes, I kept the stock plenum. Just added a throttle position sensor to the throttle butterfly. US cars have some type of throttle position type sensor there that would need to be replaced. Euro cars require some welding or fabrication to add the TP sensor to the butterfly since they don’t come with a sensor.

 

Thanks for your reply "andy...". I agree that it could be beneficial for both of us to exchange ideas and equipment specs. I will use the original throttle body and only modification will be adding a butterfly valve shaft extension to operate the throttle positioning sensor. I'm using 237 gr/min (31,4 lbs/hrs) Bosch EV injectors used standard on motor bikes.

Best, Peter

 

Whichever Bosch injectors you select, make sure you have the latency specifications (or at least close enough specs) for them as the ECU will want that.

 

I used Delphi injectors and Motec ecu. Make sure your ecu can handle injectors dead time curve so that an alternator or voltage issue doesn’t cause your fuel injection to go suddenly lean in the event of an electrical issue. Don’t skimp on a quality ecu. I want my car to start run and drive in all temp conditions just like a modern car. That takes some time to correctly tune and map.
btw- I do not use a mass airflow sensor. I use dual map sensor for barometric pressure compensation and (turbo) fuel requirements. Q

 

I had to drill out the original injector mounts. If you want to return to stock you would need to replace the intake runners. Not a big deal to buy replacements. I will try to send a pick when I return.

 

I do them like this with pico style injectors....it JUST fits.
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Adding pins to the flywheel and using the OEM pickup is my go-to for crank timing....it has 2 stock so I add another 33 to make a 36-1 pattern.

I'm using an LS version coils too (on the V12)....D585, it a truck version with a very hot spark. Again most any ECU can drive them. If you just do the crank trigger you get waste spark and semi-sequential injection so a 4 cylinder ECU will generally work fine. If you are thinking about adding a cam sensor make sure the ECU you pick has 8 fuel/8spark.

Sensors are generally up to you....you just need to tell the ECU what you have. I typically use GM stuff because its commonly available here but bosch is just fine too. On the QV TB a GM TSP fits the shaft, but you need to add bungs to screw it to and it goes on inside out for the correct rotation direction.

You need MAP, TPS, CLT, IAT, and crank trigger to get it working.

 

Yes, the 2V setup is different. I haven't done one in probably 10 years now but yes, I think I could do something similar but its more work as I need to weld up the holes and relocate them....around$1500 I guess. There are other setups with tubes or hoses to the injectors so you can retain the angles which adds different issues, pick your poison kind of thing.

 

Great thread! I recently bought a QV engine and transmission from another F chatter here. I am gathering parts for a MegaSquirt 3 conversion on it and then will install it in my 77 GTB and pickle its factory 2v engine. I am planning on running the factory intake manifold with some newer Bosch injectors and LS1 style coil on plugs with sequential fuel and ignition, then installing a Rotrex C38 supercharger once I'm up and running. I've done a bunch of MegaSquirt installs on other cars, never on one of these. It doesn't look too difficult. I'll probably post my own thread about it when I get to actually wrenching on it. I'm trying to close out a few other projects and will likely start in the fall.

 

Those are nice but too tall to get a fuel rail on top on the TB side....I've seen people split the rail or run hose/tubes to the injectors with clamps or clips to hold the injectors in place. The pico style injectors will fit, it's tight but it works

No comment on the MS choice

 

Appreciate the suggestion regarding the injectors -- will likely follow your advice there, good to know. With regards to MegaSquirt (or any other engine management really) I think installer's comfort is the way to go -- they're all relatively equal in terms of what you can do with them these days. For me, it boils down to, I've been installing and troubleshooting MS installs for about 15 years now and can get myself up and running and properly tuned pretty easily.

 

Having something you're comfortable is important.....which is why I'm not a fan for MS. They are designed to be inexpensive so the quality of the HW just isn't there. You get what you pay for. Cost savings has trickle down tuning effects, like limited table sizes which is a deal breaker for me. If the engine is basically stock or only run at the track it's not a huge deal, but I just don't build stockish engines then insist they are for street use making tuning all but impossible when the tables are limited. The rule is you need enough rpm/load points to approximately the shape of the torque curve plus any ideal condition and couple for cranking...which for me ends up in the 20-30 rpm points so 12 or 16 is a no-go.

But a stockis h QV with a blower?....yeah 16x16 fuel table is probable fine which was why my 1st though was no comment

 

I do very much like the concept of EFI not spraying in fuel during the power stroke. Waste of fuel and make HC go nuts when idle speed drops too low.

Can't a flexible hose connect injector to rail? Is there a height restriction? My thinking is Ferrari made that injector angle for a reason.