Megasquirt in '87 505 GLS

[wadehilts]

Hello all,

I have a US model 1987 505 GLS. I am strongly considering upgrading the Bosch LU2 ECU to MSII. I know that people have done this to the 505, and I love the prospect of being able to control ignition, fuel and timing via external tuning software. I am trying to develop an idea of the scope of this project and the requirements that I will need to fulfill to get a properly tuned and working system. I am looking for a general guide on a few things:

• Of all the sensors in the Bosch LU2 system, which are good ones to replace with more modern versions?
• I know I will be removing that old Air Flow Sensor and replacing it with a MAP sensor, which apparently is more more effective.
• I can't seem to find online what distributors the 505 2.2L ZDJL uses, but was wondering if the Bosch 0 227 100 124 guide on MSII website would be applicable to the 505 http://www.megamanual.com/ms2/Bosch_124.htm. I also see that they offer direct-coil control, which seems like a universal (for single coil engines) solution.
• If anyone has done such a process, could they share any roadblocks or challenges that were memorable? Anything I need to watch out for?
• Currently, I'm looking at http://www.ebay.com/itm/MegaSquirt-II-V3-0-Solder-It-Yourself-Standalone-Engine-Management-Kit-/331773631314?hash=item4d3f3fdb52:g:V1IAAOSwBLlU70-k&vxp=mtr to purchase. It seems relatively inexpensive, but I know there are likely other sensors I may as well upgrade. I have replaced the NTC coolant sensor thus far, as I suspected it was running rich at idle due to a faulty NTC.
• I have already done some reading, but haven't read all of the vast amount of general info available on MSII. I guess I was just hoping some experienced users could help narrow down the focus of my research.

That's about it! Any comments or hints/suggestions are greatly appreciated!

Wade

[my3AWDgst]

You should look at my MI16 thread. It has good information o WB and SD.

[wadehilts]

Could you give me a link to that thread? I'm having trouble finding it!

Thanks

Wade

[my3AWDgst]

 

 

[Stewart]

Hi Wade. I reckon MS2 and wide band fuel is a fantastic project. Say a trigger wheel on the front and you could lock the distributor advance and run the 1 coil and leads. I use 306 XU7 coil pack for wasted spark and run a Bosch igniter. I wrote this post on aussiefrogs a few years ago. I use the set up on my 2.2 zdjl turbo in my 404. The engine does not misfire ever and is running 10 psi at the moment on a 280 deg cam.

306 N3 coil pack and a dual channel ignitor. Tridon TIM087.
You'll need a connector from a 505 SR, STi, GTi module and that's it.
Set the dwell to 3.5 ms and thats a start.
Under 12 volt set to 10ms 13 volt 3.5ms, 14v. 3.5ms, 15 volt 3ms.

It is close to the same dwell as oem. I have read about changing dwell with rpm and one can do this however with 306 coils they are made to cope with the heat. Nice and easy.

[wadehilts]

Hi Stewart, you were probably responding to this post on my other thread? (or maybe just coincidental timing!) Anyway, I figure this post belongs on this thread, so I'll copy&paste:

Thanks for the interest and advice! My MSII kit arrives today, and I plan to get soldering this weekend. Thus far, my plan is:

• First I will do a fuel only implementation. I plan to use MSII's relay board and replace the 505's tachy relay. This is simply because I've heard about interior fires because of wonky relays, and my fuel pump occasionally has acted up (runs too long in its primer stage before cranking). This sounds "simple enough". But comes with a great deal of sensor installation.
  • CLT sensor: I will use the Bosch M12 sensor that is stock with the 505. I've bought a new one and have the datasheet to properly calibrate it with MSII's software.
  • Wideband O2: I plan to use the innovate LC-2. I'm leaning towards paying a little extra for the AFR readout that I could fit somewhere on the dash. May be useful for tuning and as a sort of "econoscope".
  • MAP sensor: built into the MSII, I'll probably tee-off my distributor or heater controls. this will go direct into the MS unit.
  • IAT: I am still trying to figure this one out. I've heard of a lot of heatsoak issues, and I want to avoid those. I'm going to be removing my AFM and replumbing my intake system with less restrictive piping where necessary (maybe just replacing where the AFM was with tubing). I'm not sure where the best place to put the IAT sensor is. I may have to do some experimentation. I'd love to talk to someone who has done this before with success.
• After a successful fuel-only implementation has been tuned, I will progress to fuel and spark control.
  • 36-1 missing tooth wheel with a hall sensor will provide my MSII with an ignition trigger.
  • I will ditch the dizzy and replace the coil with a 4-tower coil. I will then be able to use MSII to control a wasted-spark system.
• There will be significant tuning done after each step probably, but I think this will be safer than jumping into a complete implementation and ending up with no idea why the damn car won't fire!

Let me know what you guys think!

Wade

[Stewart]

Best practice today for IAT is close to the valve. I fitted mine into the plenum chamber which has turned out quite accurate.

I recall the LE systems pulsed injectors twice, it may be the same with LU. The std were  18lb/hr I think at 90%. Check here http://users.erols.com/srweiss/tableifc.htm. They may just be OK or a set from a 405 MI16 might work a little better.

One other thing is disconnect the fuel pressure regulator vacuum hose. It confuses every thing and since you're going closed loop you don't need it. I press the capsule togethher a little to give a static pressure of 3 bar but 2.5 will be ok for your project.

 

Use the pressure regulator vac hose as your ECU vac source.

 

Engines run best when at a constant temp range. Fuel starts to change state at ambient temp at 50 deg C. The important thing for economy, torque and smoothness is stable engine temps. Aim for an inlet in the plenum of  45 to 55 C Engine coolant of 85 to 95 C makes tuning so much easier. 

 

For the inlet system the easiest way for you I think is to use the existing air cleaner although that is a long way from the throttle. Pipe the same diameter of the throttle 57mm id, is just right for the job or a touch smaller will give you a little more torque mid range, ( more air speed). Maybe a carb 505 air cleaner sitting above the exhaust manifold would be neat?

[wadehilts]

Hi Stewart,

Thanks for the advice on the injectors and air intake. Using your link I was able to compare and find an injector part number that should work!

Onto the pressure regulator. I'm a little confused here. The US version, Jetronic LU2 is closed loop. We have a narrow band O2 sensor onboard. How exactly does the fuel pressure regulator work? I'm guessing it boosts the fuel pressure under heavy engine load? Is the goal here to increase the amount of gas entering the engine with proportion to engine vacuum, whereas the Megasquirt will be calculating the engine vacuum and controlling the injector pulses to allow more gas into the engine? I'm just guessing here. I don't recall my buddy Robs on AussieFrogs mentioning anything about this step. In fact, I know he got his MAP reading by teeing off of the heater vacuum hose.

Thanks again for your wisdom,

Wade

[Stewart]

The vacuum sensitive fuel pressure regulator was part of the  LE when it came out. Maybe the electronics couldn't fine tune the inj pulse width fine enough. You don't need to worry about that with your wide band control tuning and then closed loop trip. Your understanding is great. The vacuum/pressure sensitive regulator mechanically trimmed the fuel ration in areas the lambda didn't get measured. If we try to auto tune with changing fuel pressure, we have no hope of success, in my very humble experience. Fuel rail pressure changes, trim poor injector spray or performance, I found. Stability is the key mate!

[Bean]

I'd agree with Stewart with maintaining steady fuel injection pressure - Rising Rate Fuel Pressure Regulators (RRFPR's) use boost signal to up the fuel pressure so that the pressure differential between the fuel pressure and intake pressure remains steady.  (IE:  Fuel pressure at 45 psi and 0 boost = 45psi difference.  Fuel pressure at 45 psi and 10 psi boost means the differential drops to 35psi - so the RRFPR ups fuel pressure so that the differential stays constant.)

I've never heard of varying fuel pressure to account for vacuum changes...

Rabin

[wadehilts]

Hi guys, thanks for the input.

I'm conflicted on this one for two reasons:

1. A friend of mine who megasquirted his 505 2.2 zdjl in Australia, has kept his fuel pressure regulator on and had no adverse effects. He said he did this based on advice he received online.
2. Megasquirts official page highly recommends that you keep the fuel pressure regulator on: http://www.megamanual.com/v22manual/minj.htm (scroll down a bit). Hearing this straight from the horse's mouth leads me to believe that I should probably stick with the manufacturer of my EFI's advice.

Perhaps other aftermarket EFI's work differently, but it seems like I have both a theoretical and anecdotal source telling me to keep it! I guess disconnecting it isn't too difficult if I have any problems. Using the injector page that Stewart provided, I found that the US LU2 system uses injectors that output 16 lbs/min, I am buying injectors that supposedly fit the ZDJL but output 19 lbs/min (I am guessing these were used on Aussie/Euro spec cars). I chose this route because these injectors are 1/8th the price on eBay! I figure MS will allow me to control pulse width, which should give me some leeway, otherwise I may just have to get a hotter cam

Best,

Wade

[Bean]

Sorry Wade - You most definitely need to keep the stock fuel pressure regulator, I was only speaking to NOT needing to use a vacuum or boost referenced fuel regulator on a normally aspirated car.

The function of the regulator is to maintain consistent pressure no matter the load, so the injector always has 45 psi for instance.  As Stewart said - it's that consistent fuel pressure that allows you to tune it effectively.

Rabin

[wadehilts]

According to the megasquirt info page (from the link I posted above), they are suggesting that you use a fuel pressure regulator that has some sort of manifold vacuum reference. I know Megasquirt is reading the MAP constantly, so perhaps the tuning software can account for this?

Wade

[Bean]

As mentioned - I've only seen the need for the FPR to have manifold pressure reference in boosted applications. I've only ever seen it done on turbo cars - Normally aspirated cars I've had never had any manifold pressure reference ports.

Rabin

[SRDT]

You have that on the L-Jetronic, Motronic and Magneti Marelli, Renix/Bendix/Siemens from the same years.

The original D-Jetronic didn't have one bdw.

[Stewart]

My suggestion was made for two reasons, Wade. One is that the vac hose to the fuel press reg is positioned in the plenum to give a nice smooth vac signal. Two is I found using auto tune with an LM2 mapping the fuel map stabilised somewhat without the interference of oscillating fuel pressure.

I have a 280 deg billet cam, the std cam may not create and issue.

You are starting a fuel map from scratch so my approach would be to get the map done without vac, set up the ignition map then fine tune with closed loop wideband. The fine tuning could improve with the vac. reconnected at this stage. Just a few tips that work for me. This is the D Jetronic reg. The D system was the first Bosch Man Press. sensitive electronic inj using a mechanical pressure sensor. It did not use a vac fuel press reg. Vac regs came in to fine tune the very simple L jetronic and it's air flow (not air mass) sensor and air temp sensor. The three main inputs for the L system are RPM,Engine Temp and Air Flow. Air temp , tps and O2 are fine trims, as is the vac fuel press reg. With the MS2 you get rpm, crank position,tps,map, ect, iat, wideband , to trim ign and fuel.

A little to think about!

[wadehilts]

Thanks guys for the input. Stewart, I am beginning to understand what you meant. Perhaps I will have an easier time tuning if I don't add vacuum regulation right off the bat.

I began my prep fabrication this weekend, I had a bung welded to my exhaust for the wideband and I've taken off my plenum chamber and gooped up a plentiful blob of JB weld to hold on the IAT sensor bung (hopefully the stuff will hold). Managed to lose one of plenum-manifold o-rings, made for a fun 20 minute hunt around the engine bay, only to find it had rolled 20 feet across my driveway!

I plan to fabricate some sort of metal plate with a ~57mm ID cylindrical extrusion that can be installed on the existing air filter assembly, where the AFM was. Then I can run intake hose to the throttle body from there. I'll then need to find a place to mount my fuel pump relay/fuse board. After that, I should be ready to install all sensors and components.

Stewart, you also mentioned a few engine tuning points that I have yet to investigate. You said setting the valve clearances at 0.15 mm is a 'trade-secret' for this engine. I haven't yet looked in my engines manual to get the factory specs, but I am a little worried that my US-spec engine has a different cam (someone told me that, not sure if its true). Perhaps I should stick to the factory specs for my initial tuning anyways. The fine tuning can come later.

Another thing you mentioned is the positive crankcase vent on the valve cover, apparently it can cause pre-ignition at higher rpms? I'd imagine this is a bigger problem for you Aussies who have a 9.9:1 CR, whereas the US spec only has a 8.8:1. I have considered adding a filter of sorts to remove the oil from the air re-entering the engine. My 404 enlists a similar filter on its crankcase.

Anyways, back to the details of my install: I have two things I'd like to share:

1. I am fortunate enough to have a contact in Australia who has done a Megasquirt upgrade to his 505 GTI. His engine is very similar to mine, with the ZDJL LE2 injection. He is controlling fuel and spark, getting his tach signal from the distributor reluctor and driving the Bosch 123 (?) ICM with Megasquirt. I can use his tuning map to get me to a ballpark fuel map.
2. My first implementation is going to be fuel-only. I will read my rpm signal from the coil negative and use the existing ignition system on the car to manage spark. I will later add a missing tooth wheel and move to wasted-spark, eliminating the distributor and adding a 4 tower coil with a built-in igniter. I'll be sending a logic-level spark signal from my MSII to the coil.

[Stewart]

Cool, cool, cool, Wade. Nice work. I have this little bit of extra info for you. The reluctor's coil in the dist. should have a resistance of 970 ohm at 20 deg C. About 1100 ohm at 50 deg C. 

Refer to my Avatar for a smiley face. 

I'm going now to find Granny. She will have sum vittles ferr me.