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1998 #1 cylinder misfire

11K views 20 replies 7 participants last post by  bvesbc 
#1 ·
My 98 Sportage started running very poorly recently, Only code was misfire # 1 cylinder. Changed plugs, wires and even coil and then swapped coils front to rear, still no spark to# 1, prior to this we did compression test all cyl's around 130psi all seem to be getting fuel and we removed front timing cover, all marks line up and key way on crank is tight. At this point I'm some what stumped, cyl's 2,3,4 all seem to be functioning normally. The same coil fires 1 and 4, why is 4 ok but cyl 1 dosen't fire? what triggers coil to fire and do they both 1 and4 fire at the same time?, possibly cam sensor, crank sensor, ECM?? Im not sure where to go at this point, wouldn't 2,3,4 firing normally rule out a bad sensor? :confused:
 
#7 ·
Confirmed #1 no spark with tester, spark on 4 looks good , new wires and plugs, installed new coil, still no spark on # 1, still good spark on # 4, switched coil from cyl 2-3 with same result. So I can only only guess where to look now, would you think I can rule out ECM, crank and cam sensors, since I have spark on 2,3,4?? I guess that only leaves a spark plug wire being bad, both the old one and the new one?
 
#8 ·
My mind is going "tilt" on this one. If the output from the coils (1,4) is the same and you have replaced the plugs, wires, coils

if there is spark on 4 and not on 1 somehow there has to be an "open" circuit on #1 wire. (not allowing the high voltage to reach the plug/tester)

A "short" (from the wire to ground) on #1 wire would pull the #4 wire (and plug) high voltage down with it.

When you checked for spark on #1 was the #1 spark plug still connected to the wire or did you disconnect it to test for spark?

I never tested a waste spark system coil set....

i'd like to know if there ARE two separate coils (one for #1 and One for #4 plugs) being fired together

or

is there only one coil feeding both plugs.

I would think the first example (two coils) fired at the same time must be the case.

Have you tried reversing the 2 spark plug wires at the coil (1 to 4 and 4 to 1)?and checked for spark at #1 again at the end of the wires...

Have you checked for spark for #1 and #4 at the coils with the wires disconnected?
You need to confirm that both outputs (1 and 4) generate spark at the coils.

A wet plug would kill the spark (bad head gasket letting coolant into #1 cylinder).

This is a very strange problem and logically it makes no sense because of all the replaced parts. Is there any chance that the spark plug wire is getting pinched in the wire holders? Can you get a resistance reading on all the spark plug wires?

Can you measure how far in (deep) the wires go into the coils...Maybe a short wire center may not be connecting inside the coil...and a short wire would allow the problem to "follow" that wire.

I'm grasping for straws on this one...
Dave
 
#9 · (Edited)
To avoid that plug wires act as antennas, emitting electromagnetical interferences, they are not made out of metal but they are made out of carbon, so they wear out and they can break! Check that you do not crunch them when you put the cover on them, and check their electrical resistance with a good ohmmeter.
 
#11 ·
All our minds are bent on this one... By replacing the parts that you have that "should have" solved the problem... No spark on #1 but spark on #4 using the same coils and even switching them around with the same results and with new wires and plugs.

Something has to be pulling down the voltage like a wet (water) plug electrodes, something penetrating the wires on the way to the plugs or the wire ends are not going deep enough into the coil.
 
#12 ·
If the short ht lead for cylinder #4 was oil-filled, I'd be checking the short lead coil pack resistor, should be 5k ohms (4.9k - 5.1k) Ohms, and would be physically inspecting all caps / wires for carbon tracing, particularly the (original) short lead on #4 *and the resistor itself..

(I didn't see any mention of (moving) the coil pack resistor from pack #2 to pack #1 to test for positive effect)..

If any given component on the coil pack is carbon traced, it will bleed energy (spark)..

That component cannot be saved: it cannot be cleaned, etc, it has been chemically altered, the (lower) resistance value of the trace will remain, the affected component (coil, lead, resistor) must be replaced.

Hope this helps,
GottaCruise
 
#13 ·
GottaCruise...
Could you better describe the "coil pack resistor"? Is it a part external to the coil pack? does it go between the coil pack and the external HV wire?
Which plugs get the coil pack and which the spark plug wire?
I see pictures of the coil packs on rockauto but no mention of the "coil pack resistor" as a replacement part.
I'm trying to get a grip on this concept because I'd really like to help.
Dave
 
#15 ·
Sure, the coil pack resistor goes in between the coil and the short (COP) lead, the resistor is rated at 5k Ohms,

** It serves the function of limiting output current on the short (COP) secondary coil: the short (COP) lead has essentially zero (0) resistance,

if the coil / COP lead did not have the resistor, it would run as a "hot coil", that coil would overheat / fail prematurely,

It also provides some "clipping" when the coil is fired to prevent excessive EMI / EMF being generated when the coil is fired,

It also provides for the coil to retain stored energy: on any given firing cycle, the coil has 40-60% reserve energy stored for the next firing cycle, e.g.: coil generates 15-19kv energy, it takes 7-10kv energy to generate spark at the plug: the amount of energy needed to generate spark at the plug is directly related, to the spark plug (air) gap..

It takes (more) energy to fire the fuel in the cylinder on the (compression) stroke, vs. (less) energy to fire the cylinder on the (wasted) spark / (exhaust) stroke..

Anyways, that's how I understand it, I am not an Electrical Engineer (automotive or otherwise) if any of the above is inaccurate don't kill the messenger... :D
 
#16 ·
Sounds like the "coil pack resistor" may be his problem. If it opened or went high in resistance the spark would suffer on the other end of it.
The wires also have a resistance of 16k ohms per meter so they should be 8k ohms or less because they are less than 1/2 a meter (aprox 1.6 feet).
I think this might be the "missing" part of the equation.
Dave
 
#18 ·
It runs...... I now have spark to all four plugs, but I have no idea why or what caused this problem or what changed to fix it, I believe that it is totally unrelated but one of the rear windows started working for no apparent reason (it has never worked since I bought the vehicle 60K ago) so all said and done I replaced one coil, wires, plugs, ECM and a bunch of other stuff that was disassembled anyway belts and such. The catalytic converter seemed to be plugged so I made a strategically placed opening in the catalytic element. It still seems to be lacking power and struggles up hills. I will need to replace the gasket on the exhaust flange as it is leaking now but it is driveable for now....
 
#19 ·
bvesbc..
If you "punched a hole" without removing the Cat....then the secondary Cat is now probably plugged with the first's remains. That would lead to back pressure and very poor performance (especially up hill). Try removing the exhaust pipe just after the first Cat and drive it "up hill"...if the HP is back you got a blocked Cat..
RonJohn, another poster here located in Eastern PA has an "older" RIO that was causing him fits and it turned out to be plugged Cats also.

I wish I knew what caused the "one plug no spark" problem when you replaced all the key parts... There have been other Sportage posts with the same thing and no clear answer. I'm beginning to think there is a bad (weak) connection in the primary circuit wiring from corrosion causing just enough resistance to lower the high voltage on the secondary (HV) side of the coil...with the carbon resistance wire the might be just enough resistance to keep the plug from firing...Your comment on the window motor "now" working could indicate corrosion problems that "go away" when things dry out..
Dave
 
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