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Discussion Starter #1
Hello. I was checking the ignition timing on my 1990 Suzuki Vitara when I found that the ignition timing jumped about a bit at around 2000 rpm. So went to take a look inside the distributor and it parts in there that were stamped " Don´t remove". Anyone know why this is?
 

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yes, because they are factory set and you don't remove them. Timing "jumps" at 2000 rpm's are expected, this is where the ignition starts its timing advance. Remember to disable the ECM timing control of the electronic advance before setting timing, you can't just use a timing light, your timing will not be correct unless the ECM control is disbaled.
 

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You need to jumper the black/red to black wired pins, in the little white diagnostic connector box (dangling by the battery) in order to bypass the ECU, when using a timing light.
 

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Discussion Starter #5
Hasn't got an ECU nor a CPM. This is simple an electronic ignition system that is in the distributor.You can take these parts out only you should not remove there respective covers. I think that's what the manufacturer wants.Because I have got those bits out without any harm non.Now I notice that the mechanical advance weights are a bit loose. Could this be the problem.
 

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Please indicate your location and engine....1.3L. Carb?
 

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Discussion Starter #9
Here's an update if anyone is interested. Resleeved the pivots on the fly weights in the distributor. Set the timing to 8 BTDC. Car seems to be holding back under load. Reset timing to 10 BTDC. Still no improvement. Checked max advance with strobe light. As far as I can tell it gets to about 25 degrees at 2500 rpm and no more. Then starts jumping around again. Could it be those little return springs on the fly weights? They also seem a little loose.
 

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Discussion Starter #10
OK, Took the distributor apart again and measured the maximum mechanical advance. It was 17 degrees, not much I think, So 17 plus 10 gives you a total of 27 degrees. I think I could do with a bit more.I was getting roughly 25 on the strobe. However if I file the stops the weights might end up rubbing on the inside of the distributor housing. Can anybody tell me what the maximum advance should be for this car.
 

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Discussion Starter #13
Hi Guys. Here's another update.
Found out from gofastforless.com how to set the max advance on the distributor. That's how you get max power at WOT.Then you adjust the springs and stops to get the static advance where you want it. Also learned that 17 degrees distributor advance gives you 34 degrees advance on the crank shaft.I thought i needed only 20 degrees.
Looking inside the distributor I found that the advance limit bushings were missing.So I made some and fitted them.This then gave me about 16 degrees max advance. However in adjusting the timing I didn't achieve any more power. It still persisted in holding back.
Something else must be amiss or misfiring.Also the exhaust gases didn't smell right like the mixture was too rich but I knew it was right. I checked it with a colour tune.
So started looking at the coil.This is another rabbit hole not much information available.My coil gives a reading of 1.7 Ohms on the primary and 11000 on the secondary. Might not be right for my Vitara which is a 1990 1.6l 8 valve but I can't be sure that's the right coil or just too old.
So I've decided replace my electronic ignition with a hotspark and connect it to a 3 Ohm Bosch coil. I'll let you know what happens.
 

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Just remember, too much advance will also reduce power at WOT. Ask anybody that dyno's engines. Start at factory spec, work advance 2 degrees at a time until power peaks and then drops off, then back to last peak setting less 1 degree.

Your comment "Something else must be amiss or misfiring.Also the exhaust gases didn't smell right like the mixture was too rich but I knew it was right. I checked it with a colour tune." does give me a couple of clues on things to also check..
Colourtunes are ok for old carbed engines and kettering ignition systems, but usually don't work properly on injected (and carbed), cars with higher energy electronic ignitions. The spark is actually that strong it tends to give a false colour to the colourtune when you are looking at it. You could still be too rich. The fact your exhaust "smells funny" makes me wonder of you have either a mixture issue, or possibly, a partially blocked or collapsed cat producing back pressure which is why it won't rev fully.
 

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Use a scanner an monitor the fuel trims, if not within specs, investigate, MAF/MAP, O2. fuel pressure...
then put a gauge on the exhaust to rule out back pressure..
 

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Use a scanner an monitor the fuel trims, if not within specs, investigate, MAF/MAP, O2. fuel pressure...
then put a gauge on the exhaust to rule out back pressure..
1.6 and a carb, I doubt fuel trim inspection is going to work unfortunately. Need to go old school here. Exhaust gas check for Stoichiometric figure (or use a sensor on the exhaust line) Time to break out the vane engine analyser (yes I do have one and it still works!!)
 

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Yes 5 gas analyzer, have one dust covered in far corner... should start reading threads from 1st post...
 

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Yes 5 gas analyzer, have one dust covered in far corner... should start reading threads from 1st post...
surprisingly, the Vane gets used relatively often, its a nice "all in one" thats great on the early carbed electronic ignition cars, and the occasional mechanical fuel injection car that crosses my path. The scope is good too, nice trace you can see all the way across the shop
 

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Discussion Starter #19
Comment from 2013GV
Just remember, too much advance will also reduce power at WOT. Ask anybody that dyno's engines. Start at factory spec, work advance 2 degrees at a time until power peaks and then drops off, then back to last peak setting less 1 degree.

Your comment "Something else must be amiss or misfiring.Also the exhaust gases didn't smell right like the mixture was too rich but I knew it was right. I checked it with a colour tune." does give me a couple of clues on things to also check..
Colourtunes are ok for old carbed engines and kettering ignition systems, but usually don't work properly on injected (and carbed), cars with higher energy electronic ignitions. The spark is actually that strong it tends to give a false colour to the colourtune when you are looking at it. You could still be too rich. The fact your exhaust "smells funny" makes me wonder of you have either a mixture issue, or possibly, a partially blocked or collapsed cat producing back pressure which is why it won't rev full

Don't think it has a cat. This car is old 1990. Found out how to read the plugs and the fuel ring is black. They have got really sooty on idle. So must be too rich hence the smell. It has a new weber carb fitted. The next thing I shall do is check the jetting. It now has a new electronic ignition and a bosch coil but that didn't make much improvement.
At least I now know that the ignition system is good.I had my doubts about the old one.
Thank for your help.
 

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I didn't realise you had fitted a Weber, if I'd known this at the start....
Webers can be problematic on these engines. While a good carb, mounting them float bowl towards the front will result in flooding and loss of power under acceleration. This is the way people usually mount them so the throttle cable will reach them and work, not realising the problems they are about to introduce.
Float bowl to the rear means they flood and stall going downhill, which is less important than losing power under acceleration or going up hill. Plenty of discussions online on other 4x4 forums regarding Weber conversions and jetting issues on these engines. Toyota 3K carbs bolt straight up, are jetted correctly and only require a switched +12 supply for the anti diesel solenoid.
 
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