1973 Jensen-Healey with Lotus 907 2.0L

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StevenD57
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1973 Jensen-Healey with Lotus 907 2.0L

Post by StevenD57 »

I fired up my 1973 Jensen-Healey for the first time this evening running port injection with EDIS crank fired ignition. For those who are not aware, this is the 2.0L Lotus 907 motor that in US trim had twin sidedraft 1.75" Zenith-Stromberg carbs. It now has two single throat 2 1/16" throttle bodies from two V6 Nissan Maxima cars that were in a local junkyard. I have adapter plates to bolt them to the original ZS manifold in place of the carbs. I had fuel injector bungs welded into the manifold at a point where the injector squirts down into the intake port and the back of the intake valve. I am running multi-orifice high-Z injectors from a Dodge Neon. I got the EDIS crank fired ignition working first before I converted to EFI. I am controlling this all with a MS1 V2.2 board.

My current fuel pressure regulator and fuel rail is from a Saab 900 that seems to be running at 37PSI. I would like to switch to an adjustable fuel pressure regulator so I can up the pressure to around 43PSI since the Neon injectors are rated at 21.3lbs/hr at 43PSI. I mounted a swirl pot and the high pressure EFI pump in the back of the car under the trunk floor. Unlike the Lotus Esprit cars that had twin fuel tanks, the Jensen-Healey only has one tank but it is unbaffled so I am using the original low pressure pump to pump fuel into the surge tank (swirl pot) and the high pressure EFI pump pulls from that surge tank. The fuel return will go directly back to the top of the main tank.

I still have lots of work to do to get a better throttle linkage setup, the actual fuel return into the tank instead of a hose stuck into the fuel filler neck. I also need to add some sort of idle air control system as well.

BTW, if anyone is interested I have photos of the various bits and the final installation. They are all in a photo album on photobucket.com
Jaguar E-Types, modified Merkur XR4Ti, Jensen-Healey
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Philip Lochner
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Re: 1973 Jensen-Healey with Lotus 907 2.0L

Post by Philip Lochner »

StevenD57 wrote:They are all in a photo album on photobucket.com
Link please? Why MS1? MS1 has issues with IAT fuel compensation IIRC. Better place your IAT sensor in a place where it gets a relatively constant temp.
Kind regards
Philip
My MS projects: viewtopic.php?t=20086
StevenD57
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Re: 1973 Jensen-Healey with Lotus 907 2.0L

Post by StevenD57 »

Video is here:

http://www.youtube.com/watch?v=2-2bkBlF3Lc

Pictures are here:

http://s685.photobucket.com/albums/vv21 ... FI%20work/

The MS1 box was very cheap and available. I figured for a first attempt it would be an OK starting point and if necessary I could upgrade later. Right now I do not have any means of idle control. I have to play with the throttle a bit to start it and then keep it running for a few minutes after starting but other than that it runs amazingly well. I have a Bosch PWM idle valve I picked up at a local j-yard for under $20 but I am still investigating how to drive it.

When you say the MS1 has issues with IAT can you point me towards some information about that?

I still have to figure out how to do some tuning.
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Philip Lochner
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Re: 1973 Jensen-Healey with Lotus 907 2.0L

Post by Philip Lochner »

StevenD57 wrote:When you say the MS1 has issues with IAT can you point me towards some information about that?

I still have to figure out how to do some tuning.
Maybe things have changed in the mean time. Just see if you have a "MAT fuel compensation" menu somewhere. Its purpose would be to adjust fuelling as a function of inlet air temp. MS1 did not (does not??) have such a table but had fuel compensation built in using the PV=nRT formula but it seems that results in too much fuel being added/removed as function of inlet air temp. Many guys were complaining about lean running after a heat soak. IAT very high means air less dense means less fuel. MS1 (and MS2 defaults) took too much fuel away.

Perhaps also look at this: http://www.msextra.com/forums/viewtopic ... 9&p=202952

Tuning fuel is VERY easy. Set up your AFR table, buy Tunerstudio, go drive the car and let VE Analyze do the tuning for you. Timing can only really be done on a braked dyno where you can place the engine at a constant load and while you play around with timing, and see what the effect on power is. If its a high compression engine you could advance timing until she pings and then retard by, say, 4 degrees - crude but close.
Kind regards
Philip
My MS projects: viewtopic.php?t=20086
StevenD57
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Re: 1973 Jensen-Healey with Lotus 907 2.0L

Post by StevenD57 »

I am currently using Megatunix running on my Linux laptops to talk to the Meagsquirt system.
I want to go back to the Megatunix forums and see if there is any information how others are using it to do the tuning steps.

I also have a new O2 sensor on order for my WBO2 unit since it was acting a little strange and I have had it for several years.
Jaguar E-Types, modified Merkur XR4Ti, Jensen-Healey
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StevenD57
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Re: 1973 Jensen-Healey with Lotus 907 2.0L

Post by StevenD57 »

I have been driving my Megasquirted Jensen-Healey back and forth to work on a regular basis with zero problems.
This is a 20 - 25 mile trip each way. I am very happy with the performance & reliability.
Only thing I would like to figure out is how to lean it out more at steady-state part throttle cruse at highway speeds.
Jaguar E-Types, modified Merkur XR4Ti, Jensen-Healey
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Philip Lochner
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Re: 1973 Jensen-Healey with Lotus 907 2.0L

Post by Philip Lochner »

StevenD57 wrote:Only thing I would like to figure out is how to lean it out more at steady-state part throttle cruse at highway speeds.
What's to figure out Steven? Just reduce the VE values on those areas of the map when you cruise at part throttle.
Kind regards
Philip
My MS projects: viewtopic.php?t=20086
StevenD57
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Re: 1973 Jensen-Healey with Lotus 907 2.0L

Post by StevenD57 »

I know there is a difference between the VE table and the target AFR table. VE analyse live somehow makes use of the target AFR tables to auto-adjust the values in the VE table. When I looked at my AFR table though it seemed like the numbers there do not directly relate to the actual AFR ratio numbers I would expect. This is in TunerStudio BTW.
Jaguar E-Types, modified Merkur XR4Ti, Jensen-Healey
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Philip Lochner
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Re: 1973 Jensen-Healey with Lotus 907 2.0L

Post by Philip Lochner »

StevenD57 wrote: VE analyse live somehow makes use of the target AFR tables to auto-adjust the values in the VE table. When I looked at my AFR table though it seemed like the numbers there do not directly relate to the actual AFR ratio numbers I would expect.
Depending on how you configured your MS, it will use the values in the VE table, MAP(or whatever engine load parameter you use) and AFRtarget (and several other parameters) to calculate the pulsewidth required to achieve the AFR in in your AFR table.

VEAL will adjust the VE table parameters in order for the AFR in the exhaust to match the AFRs you specified in the AFR table. Once the VE table is tuned all over, all you have to do to make any area leaner or richer, is adjust the AFR table - not other tuning or changes should be required.
Kind regards
Philip
My MS projects: viewtopic.php?t=20086
StevenD57
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Re: 1973 Jensen-Healey with Lotus 907 2.0L

Post by StevenD57 »

I have been driving my 1974 Jensen-Healey with the MS1 EFI since Jan. 2011 and I recently completed a road trip from Phoenix AZ to Olympia WA and then down to Sacramento CA and back up to Olympia WA. The EFI has been working very reliably except for a problem I had in Nevada with rust from the old gas tank clogging up the low pressure filter on the inlet side of the external high pressure fuel pump. The only other issue I have is with the WBO2 unit I have displaying a slightly different AFR value on it's display verses what Tuner-Studio says the MS1 ECU is seeing. I want to try a different WBO2 system to see which AFR value is correct.

Overall the car has been very reliable for a first generation system design and first generation wiring harness.

The only major modification I have done recently is to relocate the EDIS coil pack and controller from the firewall behind the motor to the driver's side fenderwell next to the motor in an effort to clean up what the install looks like. Eventually I need to redo the actual electrical harness so it looks a LOT neater as the current one was a rough & ready one I did back in 2011 to see if everything was functional.

Also I have converted a second Jensen-Healey to the same EDIS crank-fired ignition setup using another MS1 V2.2 ECU. That car is still running 45DHLA Dellortos until I get a chance to work on switching the fuel system to the same EFI manifold design.
Jaguar E-Types, modified Merkur XR4Ti, Jensen-Healey
Linux = no virii or spyware, EVER
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