Distributorless Ignition

3A-C Power · Post by **3A-C Power** » Tue Apr 20, 2004 8:21 pm

In another thread we were talking about distributorless ignition for the 4A-F engine. To put it on, there are a couple ways of doing it - with an aftermarket system including the controller or by adapting a system from another engine that uses DLI.

Not all cars that have DLI are expensive - the Hyundai Accent has it, and that's why my friend's ignition is screwed. The 5E-FE from the 92-95 Paseo and 95-99 Tercel has it, and that engine is very well designed and efficient. The basic head design is the same as the 4A-FE, so the fuel and ignition programming should work. This would involve adapting the 5E-FE's cam angle sensor to the 4A-FE's distributor mounting location, which may be easy or hard, and using the 5E-FE ECU and whatever sensors are different in its system. There was a guy on Club 4AG who had a 4A-GE running with a 4A-FE ECU, and those engines have more of a difference than the 4A-FE and the 5E-FE.

Now looking at the reason why you can't just use the DLI coils with a non-DLI ECU, as far as I know, a distributor ignition system that is electronic ignition only relies on the distributor to distribute the spark between the 4 cylinders. It does control the timing electronically. A DLI system ECU gives an output to each coil whenever that corresponding spark plug needs to spark. The regular ECU just gives a signal to the one coil, and from there it goes through the distributor cap to the right spark plug. The DLI systems I've seen only use two individual coils, not 4, so every time a spark plug goes off for the between the compression and power strokes on one cylinder, another spark plug goes off in another cylinder that's between the exhaust and intake strokes. It must be possible to design a solid state electronic device that takes input from the crank or cam angle sensor and the ECU ignition signal, and outputs the ignition signal to the appropriate coil based on the crank position. I could make a mechanical device that does this, that could be very small and attach to the end of the camshaft, but an electrical device that runs off the cam angle sensor would be better. This would have serious implications for the 20-valve 4A-GE community, as it would be the first cheap and effective way to overcome the distributor/firewall conflict without having to overcome the firewall with a hammer. I can make a mechanical one just like the commutator on a DC motor and with similar annoyances, but Nick must be able to do better.

GTSSportCoupe · Post by **GTSSportCoupe** » Wed Apr 21, 2004 9:18 am

Cool! I didn't know that those other engines came with DLI too!

Yup, I could design a cheap and effective unit to interface DLI systems to non DLI ECUs. Obviously the best DLI system to use with 4AxE engines would be that off of the JDM 4AGZE engines. This is expensive and tough to get though. I know that the coils at least from the 7MGTE engines can be used, not sure if the crank angle sensor bolts on or not though.

This is a pretty cheap solution here: <a href='http://picasso.org/mjlj/?q=' target='_blank'>Megajolt</a> . The guy is using this along with Megasquirt fuel delivery on a 260hp+ 4agte engine in his AW11. I think he designed the Megajolt system himself.

3A-C Power · Post by **3A-C Power** » Wed Apr 21, 2004 9:24 am

Does the Megajolt use its own ecu? If you use it, would the original ecu still be able to control fuel?

I want something that runs off the 20 valve cam angle sensor. Maybe there's a problem with sending a signal from the 20 valve ecu to a 7m-gte or 4a-gze dli coil? Maybe they require a different voltage input? That would have to be designed into the electronic adapter but it wouldn't be hard for an electrical engineering technician. I could use 4 seperate 20 valve igniters and coils but those are kind of expensive. I heard at least one of those is the same as a truck or 4runner one and if that's true, it wouldn't be a bad option. For me, it would be cheaper just to relocate the distributor to the front, but I'd rather use the DLI if it's available.

GTSSportCoupe · Post by **GTSSportCoupe** » Wed Apr 21, 2004 10:21 am

I would recommend reading through the Megajolt website to learn more about the system. I'm sure there is an email link on there you can use too to email the designer with your questions.

I'm sure an interface could be designed to use the 20V cam angle sensor instead of a 4agze crank angle sensor. The signal from the 20V ecu will need to be re-constructed for the DLI coils.

I can easily design this and have all the info necessary to do it. I just need a 20V 4age to test it on. It'll be at least a year before I buy one.

If anyone would like to learn more about Toyota EFI and Electronic Ignition systems, read through the OBD I articles at this site (articles 20-27): <a href='http://www.autoshop101.com/techarticles ... icles.html' target='_blank'>http://www.autoshop101.com/techarticles ... es.html</a>

(I'm an Electronics Engineering Technologist BTW, not a Technician

, and work in the position of Senior Hardware Design Engineer at the company I work for.

)

3A-C Power · Post by **3A-C Power** » Wed Apr 21, 2004 11:06 am

Do you think we could collaborate on it? I'll be buying a 20 valve pretty soon, and I can do testing and put a bit of money in for development. I can learn some electronics to do my end of the job which is something I want to learn anyways. You are way ahead of me because I may or may not be a mechanical engineer depending on my grade report and whether they let me write the exam I missed yesterday, and I have no job. I'll be reading through those Toyota articles when I have time.

tercel4wdrules · Post by **tercel4wdrules** » Wed Apr 21, 2004 1:51 pm

3A-C Power wrote: In another thread we were talking about distributorless ignition for the 4A-F engine. To put it on, there are a couple ways of doing it - with an aftermarket system including the controller or by adapting a system from another engine that uses DLI.

Thanks 3A-C Power! I really I am interested in doing something like this, but this seems like something worse than putting a 4A-FE and switching over to EFI. Well maybe you and Nick can come up with an efficient one that is cheap so that I can carry on my 4A-F swap. In what Corolla years was the 4A-F available in?

tercel4wdrules · Post by **tercel4wdrules** » Wed Apr 21, 2004 1:54 pm

GTSSportCoupe wrote: (I'm an Electronics Engineering Technologist BTW, not a Technician , and work in the position of Senior Hardware Design Engineer at the company I work for. )

Well Nick in about 7 years I'll be joining you guys (3A-C Power and you) as an engineer. We can work together making the Tercel 4WD better.

GTSSportCoupe · Post by **GTSSportCoupe** » Wed Apr 21, 2004 2:35 pm

3A-C Power wrote: Do you think we could collaborate on it? I'll be buying a 20 valve pretty soon, and I can do testing and put a bit of money in for development. I can learn some electronics to do my end of the job which is something I want to learn anyways. You are way ahead of me because I may or may not be a mechanical engineer depending on my grade report and whether they let me write the exam I missed yesterday, and I have no job. I'll be reading through those Toyota articles when I have time.

3A-C Power: I'd totally be interested in collaborating. It won't take much money to develop, just time and an engine to test on. Time is the hard part for me. You'll make your mech engineering man! Think positive

. They won't keep you from finishing because you couldn't make one exam (unless they are real A-holes about it). You'll find a job too, although you might have to settle for a starting job that is not as involved in design as you would like. It is a very tough market for mech engineering positions right now; it's tough even for elec engineering too. Have fun with the Toyota articles. If you read their first series you might learn some new things about electronics to.

Tercel4wdrules: Best luck with your engineering plans! It is a great occupation to get into, but lots of work to complete. Prepare to have no life for a while (school takes all your time - at least mine did).

3A-C Power · Post by **3A-C Power** » Wed Apr 21, 2004 3:01 pm

I did read part of the electronic ignition article today, I couldn't help it. It appears that it's the Variable Spark Advance system that I'm dealing with, and the 22R-E engine has it, so the 22R-E igniter from a truck or 4runner should work. The job market is not bad here. There are lots of jobs, and lots of people that are getting jobs. I have applied for several entry level mechanical engineering positions that I'm qualified for, but haven't heard a word from either employer. It just means that other people got the jobs, and that's okay because other people need jobs just as bad as I do. At this point, I will settle for any job that moves me towards a career, like the job I worked at last summer at the machine shop. At worst, I will be changing tires at Canadian Tire for $9 an hour because that's a job I can get. I hope it doesn't come to that because I don't know if I can handle it, being treated like garbage while making shit for wages after working so hard for my degree.

tercel4wdrules · Post by **tercel4wdrules** » Wed Apr 21, 2004 6:49 pm

3A-C Power wrote: The job market is not bad here. There are lots of jobs, and lots of people that are getting jobs. I have applied for several entry level mechanical engineering positions that I'm qualified for, but haven't heard a word from either employer. It just means that other people got the jobs, and that's okay because other people need jobs just as bad as I do. At this point, I will settle for any job that moves me towards a career, like the job I worked at last summer at the machine shop. At worst, I will be changing tires at Canadian Tire for $9 an hour because that's a job I can get. I hope it doesn't come to that because I don't know if I can handle it, being treated like garbage while making shit for wages after working so hard for my degree.

Yeah, this is what I'm afraid of, because it seems like engineering is a very competitive job. Right now I feel like I want to be a computer hardware engineer, but then again computers are very competitive. Well unfortunately if you don't get a position at first then you either have to start from the bottom and then work your way up or settle for less. Experience I think also has to do with this. In California it looks like computer hardare engineering pays more than mechanical or electrical engineering. 3A-C Power I wish you luck so that you can find a decent paying job to pay off all that hard work.