1981 jeep cherokee

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alexander
Posts: 246
Joined: Sat Jan 19, 2008 4:33 am
Location: sydney, australia.

1981 jeep cherokee

Post by alexander »

ok! i have just completed my second installation, this time in my jeep. the jeep already had a Hall Effect ignition, and ran quite well because of that. problem was that it is has a dual fuel setup, and mostly runs on lpg, which is generally about 40% of the price of unleaded in australia. lpg and petrol require different ignition timing in that lpg needs more advance at lower revs, and less at higher revs when compared with unleaded. thus, the setup is an obvious application for MJLJ. and, of course, it gave me an opportunity for more fiddling, and that lovely warm smugness which derives from setting up something complicated and electronic, and which our friends and family cant even understand when explained to them. so, here goes..

the car in question. it is a 6l V8. i had these "16 valve" stickers made as a piss-take on the similar stickers which used to be plastered all over small japanese hotties, when 16 valve was an emerging standard. in almost a year, the only person who has got the joke is the mechanic i use (only when i really need to, of course)!

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i used alexander_monday's really clever idea of drilling holes in the harmonic balancer, instead of a trigger wheel.

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the balancer had a hole already in the periphery, which was NOT what i needed, so i ground down the end of a piece of steel bar, and smashed it into the hole with a sledge hammer with a bit of glue, and ground it off. what hole!?

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VR sensor mounted on a suitable bracket. i avoided using proper connectors (didnt have them; too cheap to buy them) buy pushing mini spade type connectors onto the pins of the VR and coil packs, then glueing them in. i then put cheap hobby shop type connectors on the other end of the wires.

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VR sensor would be no more than 1mm from the balancer...

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this is the output of the VR. note that the waveform is in reverse, but that is simply because of the way i had the probes connected at the time. in reality, the VR is - of course! - connected with correct polarity in the loom. the digital oscilloscope was a cheap ebay job - about AUD150 - and while it may not exactly suit high end users, i was really pleased i bought it. it weighs nothing, can sit in the car, and was really useful when working through an initial problem with the installation.

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coils and EDIS mounted in engine bay...

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i got a numbered set of plug leads with the coils, but of course all the wrong lenghts. so i put them in the right place, cut them to length, and crimped new ends on, with new boots. if i did this again (run out of cars for now, however) i would use some other coil packs which accept normal spark plug leads. the ford connectors are all very well, but using standard leads would be cheaper and more flexible.

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i used this coil testing jig to check that the EDIS was working, during the project.

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lastly, i even went to the trouble of making a proper coloured wiring diagram for the back of the shop manual, so in a year's time i will have a clue what i did. (see attached PDF).

next projects are to install a digital dash, and then megasquirt, in my lotus. as you will ALL understand, that is just to keep the fidgeting fingers occupied :)

regards
alexander.[/img]
Attachments
jeep megajolt wiring diagram2.pdf
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