Newbie!! a puzzled one at that!!

EDIS and Megajolt installation related topics. Be sure to review the <a href="http://www.autosportlabs.net/MJLJ_V4_vehicle_installation_guide">Vehicle installation guide</a>

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Scottie
Posts: 4
Joined: Sat Sep 01, 2007 9:10 pm
Location: Benfleet, Essex

Newbie!! a puzzled one at that!!

Post by Scottie »

Hi everyone!

I'm new to this site and to Megajolt. I'm about to start building my forth lotus 7 style kitcar, all of which have been pinto based in the past. On this project i'm going down the 2.0l zetec (silvertop) route. I'm planning to run the zetec with zzr1100 carbs. I've been in discussion with many people on the kitcar owners forum about mechanics such as changing the flywheel to take a type 9 box etc and have been told that i needed a Megajolt TPS version to run the zetec. I have since purchased a MJ lite Jnr, complete with all the leads and software.

As i have not done this sort of installation before i have no idea where to start. I have been reading the Assembly and Installation guide, which for the moment, and until i read them at least another three or four times, haven't really sunk in to well!!! I do have a couple of questions.

1) The software i have has some MAP's included, one of which is a 2.0l zetec 2d map. What is the difference between 2d and 3d? and what does this mean?
2) When i finally get the engine, wiring, MJ, etc all plumbed in, start the car (which if i understand will start and run but will work only from the EDIS and effectively be in limp mode) do i literally save the MAP i have to the flash memory of the MJ box? How is this done? Is there a definitive MAP for a zetec on bike carbs that i will benefit from?
3) I heard the term PIP and SAW a few times now. What do these mean and what do they do?
4) I've also heard a lot about shield cable. What does this do? and also about earthing it, how is this done?

As you can tell i'm a real novice to this and all your help will be appreciated!

Regards,

Scott.

Sorry, one more question. I see that you can have the option to switch between two maps via an in car switch. What are the benefits of this? and what situations would you use two diff maps?

Scott

DannyP
Posts: 417
Joined: Sun Apr 09, 2006 3:48 pm

Post by DannyP »

I still don't have mine installed, but I can answer some of your Qs
1. 2D is a regular x-y axis graph. At x rpm, advance value is y.
3D adds another variable, either TPS(throttle position sensor) or MAP(manifold air pressure or vacuum). TPS or MAP is for load sensing, usually more advance can be added at partial load, i.e. part-throttle cruising.

2. There is a lot of info on the "how to" section of this site to answer your questions. A good check of the system is to start out with EDIS only, then add the MJLJ to verify advance change with a timing light. I believe there should be a starter map already flashed to your chip if you got it from Brent.

3. PIP basically is an rpm output from EDIS to MJLJ. From this and load, MJLJ sends an advance value signal back to EDIS on the SAW line.

4. Shielded cable has a foil and/or a braided wire wrapped around the signal wires to protect it from noise, which is prevelant in a metal engine compartment with ignition going on. It should only be grounded or earthed on one end, the EDIS end. PIP,SAW, and crank sensor need shielding.

5. If you want to baby the engine, an extra map is good. Also if you use pump gas and switch to race gas. Also if you want a valet mode with less advance and a much lower rev limit :roll: .

Hope I helped you out. Love sevens, Ztec sounds like fun!

Scottie
Posts: 4
Joined: Sat Sep 01, 2007 9:10 pm
Location: Benfleet, Essex

Post by Scottie »

Thanks for your reply. I'll have a look at the 'how to' section and should hopefully help with my queries. My concern at the moment is if i load the MAP i have and car runs well, timing advances when i rev the engine but there is a flat spot mid revs or the carbs are popping and farting and missing for example, i have no idea whether it needs advancing or retarding to clear the problem, and do i just go into that table of values and increase or decrease the values at the the corresponding point of revs on the table to sort the problem?

Does the shield cable shroud the existing cable or do i have to replace the cables entirely? Where is the best place to get these cables?

Scott.

MartinM
Posts: 433
Joined: Sat Aug 27, 2005 12:08 pm

Post by MartinM »

To get everything spot on, you need the fuelling and the ignition spot on.

Flat spots can be either...
Carbs popping and banging can be either...
...which isn't much help really 8)

Shielded cable - look at the bottom of the wiring section on http://trigger-wheels.com/store/index1.html

Use the search on the forum - the forum is getting to be a good repository of information - and ask any questions you can't find the answers to yourself

...and it's best to write map (as in the 3D ignition map) and not MAP (as in Manifold Air Pressure) - or confusion will reign!

Darrenw
Posts: 10
Joined: Fri Mar 23, 2007 2:22 pm

Post by Darrenw »

Do your ZZR1100's have TPS fitted? Mine didnt so i had to adapt one of the throttle spindles. I posted some pics in locostbuilders.

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