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ZUKIWORLD Discussion Forum => Suzuki 4x4 Forum => Topic started by: wapitijames on November 21, 2011, 01:22:49 AM

Title: weird spark issue
Post by: wapitijames on November 21, 2011, 01:22:49 AM
When my 94 1.6L 8-valve is idling, if I remove the sparkplug wires one at a time, the idle changes and gets ruff. That is expected, but when I remove the plug wire to the #1 cylinder there is no change at all???? Any thoughts? I've changed the cap and rotor, and the wires and plugs, I'm at a loss. My gas mileage is horrible and there is no power, I cleaned the EGR system, it was quite clogged, but no change.
Title: Re: weird spark issue
Post by: fordem on November 21, 2011, 05:44:34 AM
Have you done a compression test?

Something I find odd is the lack of the word miss or misfire in your description of the problem - when a four cylinder engine has a cylinder not firing, it's usually quite noticeable, even at idle - and not just as a lack of power, which you do mention.
Title: Re: weird spark issue
Post by: wapitijames on November 21, 2011, 02:31:08 PM
At idle, it runs quite well, not perfect, but pretty well. It's shakes a little at idle and a little sputter when you give it gas, but other than that it appears to run well. I don't know that it's ruff enough to call it a "misfire" though, but I'm not a mechanic either. What could cause 1 cylinder not to fire though?
Title: Re: weird spark issue
Post by: SnoFalls on November 21, 2011, 03:14:39 PM
When was the last time you adjusted the valve lash (this is a "maintenance item"). Should be done at every 60k miles at least (IMO).

It also sounds like you're definitely not getting any "firing" of the #1. With new plugs/wires/cap/rotor, I'm going to guess that there isn't any compressed fuel to ignite. Do you have an inductive timing light to check if/when #1 is firing?

I've had some 8v's have the lash so far out it's scary (aka never adjusted for 180k miles). Thankfully, those engines were always "loose", but a tight exhaust valve can cause "burn by" which means little to no compression and ignition of the fuel in the cylinder is going to be sketchy.

I would suggest a compression test, and then adjust the valve lash, then compression test again ...
Title: Re: weird spark issue
Post by: wapitijames on November 21, 2011, 07:28:33 PM
I'm not sure about the timing light, I used my neighbor's timing gun to set the the timing, is that the same as a light? I've only had the Tracker for 20,000 kms, so I don't know if/when the valves were adjusted, it has 400,000kms on it and does burn oil or blow smoke. I will try the valve adjustment on my next days off, thanks for the info, it is much appreciated!!
Title: Re: weird spark issue
Post by: wapitijames on November 21, 2011, 07:30:36 PM
Sorry...........I meant "it DOESN"T burn oil or blow smoke".
Title: Re: weird spark issue
Post by: ebattleon on November 22, 2011, 11:07:57 AM
You could have the head gasket blown through the water ports or inter cylinder, or leaking valves...you need to do a compression test and a leak down as well. Also you could have a bad spark plug on that cylinder try switching it spark plug with another and see if the problem moves with it.
Title: Re: weird spark issue
Post by: wapitijames on November 22, 2011, 03:19:21 PM
There doesn't seem to be a problem with the head gasket, no antifreeze in the oil, no white smoke, no missing antifreeze etc. I have moved the sparkplugs around with no difference at all, it's always #1 cylinder. I'm going to do a compression test this weekend, I believe the valve lash is going to be the problem though, thanks for the comment.
Title: Re: weird spark issue
Post by: Capt on November 22, 2011, 04:08:00 PM
Have you tried to SEE SPARK at this plug by turning/running it out of the cylinder spark plug out grounding it to the block?

Shine a flash light into the spark plug hole at TDC and see if you have burnt a hole into the top of the piston.

You may have a burnt or bent valve. Something as simple as a tiny carb screw getting sucked into your engine can reek REAL HAVOC !!

CAPT
Title: Re: weird spark issue
Post by: wapitijames on November 22, 2011, 07:26:08 PM
I have checked for spark, there is definately spark there. I will have a look tomorrow at the piston through the sparkplug hole, thanks for the tip.
Title: Re: weird spark issue
Post by: wapitijames on November 27, 2011, 09:32:22 PM
Okay, so I checked the piston, no hole that I can see. I set my valve lash and it runs much better and the gas mileage has improved ALOT, I hadn't driven it much since I cleaned the EGR system so that might have been part of it. Still doesn't seem to be firing #1 cylinder though, I think I'll swap out the ECM next..................unless someone has more thoughts?????
Title: Re: weird spark issue
Post by: Skyhiranger on November 29, 2011, 07:45:52 AM
I'd do a compression test on #1, as suggested previously.  If #1 has no compression, or low compression (80psi or lower), then removing the #1 wire won't change how the engine runs.
I'd guess you have a burnt exhaust valve on the #1 cylinder and that is causing a compression loss.
Title: Re: weird spark issue
Post by: wapitijames on November 29, 2011, 11:52:55 PM
Okay, I will try that on Thursday and see what it has for compression. If the exhaust valve is burnt, should it be blowing smoke? Mine doesn't blow smoke at all, it does smell a little rich though, thanks for the tip!!
Title: Re: weird spark issue
Post by: Skyhiranger on November 30, 2011, 05:29:05 AM
Okay, I will try that on Thursday and see what it has for compression. If the exhaust valve is burnt, should it be blowing smoke? Mine doesn't blow smoke at all, it does smell a little rich though, thanks for the tip!!

I had an engine that had 2 burnt exhaust valves and it didn't blow smoke.  It would hardly run, but it didn't blow smoke.
Title: Re: weird spark issue
Post by: locjaw on November 30, 2011, 05:33:21 AM
you can make a 4 cylinder run pretty good on 3, but not on 2 skyhiranger  :P
Title: Re: weird spark issue
Post by: Skyhiranger on November 30, 2011, 05:37:10 AM
you can make a 4 cylinder run pretty good on 3, but not on 2 skyhiranger  :P

Yeah, I know all about it. ;D