Blind Freddie

Ok, so far i havn't been able to get the ECU to test that, but i just noticed then that my ECU ground nut was loose, that probably explains my formerly hunting idle...
Anyways, i just tested the leading coil resistance without taking the wires off the terminals, and after a bit of jumping around, i got .000 ohms resistance. According to the haynes manual, it should be .02-1 ohm, do you think this .000 could indicate something shorted in the coil? I'm going to test the resistance of the other coil now if i get a chance, if that's .000 too, then i doubt it's a problem.
Is there a safe way to check which, and whether, leads are getting spark with just a multimeter?
Well, hopefully i'll get the ECU tomorrow and i'll test it out, wish me luck and thanks again for the help everyone.

Dan.

WAYNE88N/A

For all practical purposes, there is no difference whatsover between .000 ohms, and .02 ohms... The coil windings are good- remember, you're basically reading a wire...

Try to isolate the coil (take at least one terminal off), and take the readings again, that way you'll be sure your 0 ohms is not back through the circuit (the "wrong" way)

Blind Freddie

alright cool. Well i'm off to get the ECU now, i'll let you know how it goes, hopefully it's that, it's a easy fix.

Blind Freddie

Hey,
Ok it musn't be the ECU. I just tried another standard ECU and it's doing the same thing, took ages to start it, lots of grey smoke came out, and it just stalls when you do anything. It must be something in the ignition circuit, something preventing it from providing enough spark, this is just my guess, any ideas anyone? Could this be starter motor related??

WAYNE88N/A

Does the motor "shake", as if it's running on only one rotor?

Do you have an inductive timing light to check the plug wires? If not, use a small flourescent bulb & hold it close to each wire to see if it's "phosphoring" (needs to be kind of dark to see it).

Do you know how to take voltage readings at the ECU?

Blind Freddie

Ok i'll get a phosphorous bulb and try that when i can, i'll ask my friend if he'd have a blub that'd suit.

Nah i'm not sure how to take voltage readings at the ECU, that would tell me whether the ignotors are ok right? among other things probably... I reckon i could work it out if i was given instructions, as long as there isn't a risk of wrecking the ECU or something.

And yeh the motor kind of shakes, it runs pretty rough, but how would the spark cause a whole rotor to not work? Would that indicate that one coil pack or ignotor isn't working?

88seAQ

Here is what I think now with the info provided. You have a wire shorted or burned in two what you need to do is get wiring diagrams for your 7 and check resistance from one end of each wire in your ignition (spark) circuit check from dist to ecu, ecu to coils and all included in that circuit and make sure that there is not an open there and then if no opens you want to make sure that there is no wires shorted to ground. Sound hard, ............................your right, well not hard just time consuming and brain racking (I know already racked LOL) good luck at least it is just an inexpensive wire more than likly and it won't cost an arm and a leg to repair it will just cost a week and a month to find. Well happy hunting and good luck WB/w how things go.. talk to ya later

Blind Freddie

Hmm ok, how will you know what resistance to expect for a short though? An open circuit you'd expect no resistance, or extremely low, but even extremely low resistance is normal for some devices, like the coils.
Otherwise how would you know what's a short by the resistance readings?
Thanks

WAYNE88N/A

https://www.rx7club.com/showthread.p...roubleshooting

This is my first attempt at making a link, hopefully it works

WAYNE88N/A

A short answer to your question, Blind Freddie-

A short will read 0 ohms on your meter, set to resistance, with ALL power off of the car...Shorts are funny animals, though, because some components will read good with the meter's puny power sources, but when the real "juice" starts flowing, the component will short (coils are famous for this). That's why I advocate troubleshooting for shorts by isolating different components within the circuit, and burning through a couple of cheap fuses. If done right (continually "splitting" the circuit in two), usually by the second or third fuse you've nailed the bastard...

Well hell, I wasn't planning on typing this much...

As long as it helps the boys...

An open will read infinity (the funky sideways "8" symbol), or the meter needle will not move, or the digital meter might read "OL", for "open lead"...

88seAQ

also if you are on a circuit that should have power you should not get a reading to ground accept for mabey a high ohm reading through whatever is getting the power if you have low reading (resistance) through a wire that is supposed to be power, say less than 2 ohms you probably have a short, which is a wire that is supposed to be power that is going to ground before the part that is supposed to get the power. I think I would start with all the ignition grounds then check ecu grounds see if mabey one of them burnt up when you touched the cables I am not sure of your electrical system knowledge, but if you know anything about voltage drops then you should test for them that is basically test voltage when off the test to see when the circuit is operating to see if the voltage to the system is droping off meaning that there is a voltage loss due to poor conectivity at either the ground or power source. Well gotta go for now keep the info coming on what is going on hope to find the problem soon..!!!!!!!!!!!!!

WAYNE88N/A

Lol, hey 88seAQ- I want you to read what you just wrote, and you can only take a breath at the periods at the ends of the sentences- if you pass out before you're done, don't let your forehead hit the keyboard, or you might post something unintelligible

88seAQ

sorry i guess it did kinda run on and on and on and on and so on and etc. and so forth LOL electrical is a complicated thing and I was in a rush sorry again I hope you can make sense of it. NOW THAT'S A RUN ON SENTECE!! HA I AM KING OF THE RUN ON.