F355 coil-on-plug conversion

I am not sure. I don't remember a specific reference to that replacement in the service reciepts I have of the car. I have a '99, you think that the car would have already came with the right alternator ground strap? Another thing I will have to check.

Where did you get the 16 ga. teflon coated twisted wire you used for your harness?

Alex

 

Finally getting around to hooking more and more of this up (well building the wiring harness while I finish my tranny) and have a question. I think I know the answer but I figure it's worth asking once rather than screwing up later.

Below is a picture of the coil pack and power module from the Motronic 2.7. I am thinking that two negatives and positive wire that I need to pull into the DIS-4 are the ones coming in on object 11a (coil power pack) on inputs 2 and 7 and not the ones going into object 22a/b (the actual coil) on inputs 1 and 3.

Am I correct in the logic here? I believe I am as the DIS-4 will want the signal directly from the ECU and not through the coil power pack BUT I just wanted to make sure I wasn't being stupid.

Thanks guys.

BTW does the 355 have the same coil power pack / coil assembly as shown here?

 

Arg here is the pic...it showed up before for me but seems to have disappeared.

Sorry about that.

Image Unavailable, Please Login

 

I think I am correct in pulling my inputs from the object 11 in the chart above BUT just wanted to be sure. I'd love to have thing fire up right the first time.

 

I have the outputs from the ECU isolated and they are the ones that correspond to inputs 2 and 7 on the coil power pack. But those lines flow through the coil power pack and into the actual coils via two more wires.

I am pretty confident in my original theory that its input 2 and 7 on this side of the engine. Thanks for the help Jeff...I will let you know more when I get the setup further along.

 

I already took your advice and ordered the same set you did from McMasters so we'll see how she works out.

I am really looking forward to getting this done, as it should make a big difference on the track and street!

 

Nice thread, lots of cool info.
Just wondering if it is possible to check the resistance of the coils at the dis4 unit, is there a connector? or just wires from the unit? may help find problems in the harness(es).
Also, part throttle will have the ecu adjusting the mixture based on O2 sensor response, if the sensors are crapping out they may be forcing the mixture too lean during the normal rich-lean cycle. If the sensors are origional, it may be worth putting new ones in. I would only replace the pre-cat sensors on 96-99 cars.
My 2 cents

E

 

Guys, it is time to get serious about this conversion on my F40. What is the longest COP that you have seen? I'm tired of buying used COP's on ebay and finding that they are too short. I can't remember which ones I have ( I'm at work), but they are too short. Would be willing to trade mine for longer ones. Also, did anyone ever find a source for the connectors, Motec, FoMoCo, etc., Thanks for the help and goodbye plug extenders.........!

 

Extremely useful & interesting thread, nice one Jeff

 

You can get all teh connectors you need from Motec ,even the ones for the cops .

 

Thanks for the help fellas. The f40 valve cover has a large lip to accommodate the plug extenders. If it were not there I could use the honda COP. Might get another set of covers and modify anyway? Anyone know of some F40 valve covers for sale? Do they interchance with anything like a 348? I know that the gaskets are similar to a 328 QV.

 

So I have been working like a mad man trying to get this COP conversion nailed down before I rewire my F40 for a Motec m880, ADL dash, and a CDI-8. I have had problems in the past with the coils, plug wires, and the spark plug extenders. My car caught on fire about 4 years ago when one of the coil packs went bad. All of the fuel from the two nonrunning cylinders ignited in the exhaust pipe and the resultant flames melted my rear bumper. The melted rubber went all over the back of the car and burned the entire rear end. I was doing about 90 MPH at the time and the car started to run rough. I thought that I was running out of gas since I had been on reserve for about 20 miles and was trying to get to the shop to refuel with 100 plus octane. I slowed down to try to make it to work but as soon as I did my right side "Slow Down" light illuminated. I looked back to pull over and all I saw was flames. I had recently installed an on-board fire system but the outside of the car was burning. I did not have a hand held extinguisher ( now I have both). I was able to put the fire out with my jacket. The damage was melted tail lights and burned paint. An easy repair. I vowed to improve on the wasted spark ignition system. Yesterday I decide to go to the Honda dealer and order a 929 COP. They don't have one in stock but I order one, $52.00. I also call Bob Norwood and he sends me one of his favorite COP's. I drop by to see David Moore (Moorespeed, Austin Texas, a Motec distributor) to discuss the situation. We find a lot of possible solutions but all have issues. Seems that a 575 M has COP's and they are the right length. The rubber sealing boot is the wrong size, DAMN! While I an there, David shows me a stray Ferrari plug wire. On the top is a really neat boot that seals in the plug hole. I just happen to have my too short COP with me. I wonder if the boot will fit over the COP? It fit perfectly. David cannot find out what the plug wire was for but we narrow it down to a 348. After about an hour I have to leave. When I get home I discover that the rubber boot is the same as the ones on my F40. Cool as hell. Today I get the COP form Bob Norwood, its the same as the long one in the picture and hopefully the same as the 929 honda. I test fit it and the COP is perfect! The factory F40 boot fits right over the COP with the connector in place! It looks totally factory and it is water tight! I don't have to fabricate anything. This conversion is going to be easy. Thanks to Bob, David, Jeff, and everyone involved with this topic, I wouldn't have been able to do it without you.

 

Pictures, Man! You've got to take pictures of the COP setup to look OEM on an F40!

 

Hello,

Would like to hear from those who have performed this conversion...Jeffrey Davison, Bill Wann, Alex V, mrknowitallf40 and anyone else.
Jeffrey, since you are the Originator/Developer of this conversion, how has it been working for you? Since your last post have you made any changes or modifications to your original concept?

Alex V, did you ever get yours dialed in? If so, what turned out to be the cause of the problem you were having?

Bill Wann, did you get your spacers made? If so, would you make additional sets?

Look forward to hearing from all...

 

Nope, never got mine to work properly. I still had that misfire between 2500 and 4000 rpms, and an intermittent misfire between 6-7k rpms, no matter what I do. As a last resort, I took off the COPS, rewired the harness so the outputs of the DIS-4 connects to the factory coils, as was the original design of the DIS-4. Guess what? The misfires were still there.

I finally bought a new set of spark plug cables from Kingsborne ($150/set), and a brand new set of NGK Iridiums ($8 per plug), now the car runs great.

I am inclined to think right now that the DIS-4 unit itself was at fault, as I was still having the misfires even after running it with the factory coils. I've shelved the project for now, plan on getting rid of the DIS-4 and will investigate other similar boxes from other manufacturers (I hear AEM has a similar box that might work).

I would still like to pursue this in the future, though, perhaps when a box specifically designed for a wasted spark COP conversion is made.

Alex

 

AV did you ever replace the DIS-4 box itself? I am wondering if you just got a crap box that was defective. Seems it would have been worth sending it back to who ever you got it from to see if there was an issue with it.

I havent see what you saw happen with anything from MSD but I have seen it on other cars with the Accel product line due to faulty or cracked internal components.

Anyway sorry it didn't work out for you....I still have yet to start my 348 project but will do it soon here as I have my transmission just about back together. Going to wait until after the first trackday so I dont screw it up to bad.

 

Well, I am just happy for all you guys that got the system to work perfectly. Maybe I just got a defective box, but just haven't had the time to get around to get it fixed or replaced. I have moved on to other car projects for now. Besides, I got the box from another F-chatter, so I am thinking warranty repairs is out of the question. And the fact that the MSD techs themselves keep telling me that the DIS-4 won't work with COPs wired in parralel, is slowing convincing me to try boxes from other manufacturers. Oh well...

But the short time I had the system in the car, I can tell that it has the potential for significant improvement. I will keep watching this thread for any new developements others may have, and will post any new ideas I may come up with.

Regards, Alex

 

I keep hanging up on the concept that these aftermarket engine computers are "for track only", and have no engine diagnostics. For me, the big shortcoming of the stock equipment is the lack of on-board diagnostics.

Plus, I'd like to use the existing flywheel sensors, to the degree possible.

I like the Motec package, but I keep wanting to do my own programming.

Do any of these manufacturers sell their computers with a "programmer's reference guide"?