Hesitation / Loss of Power problem - 2002 P5

R

Robotman

Member
Hey guys, I was wondering if I could get some help diagnosing a problem before I take it in the mechanic.

The problem:

A sudden loss of power, typically at mid-to-high RPM's, under load. The problem first happens quite faintly, barely noticeable then progressively gets worse over the next few minutes. Under low rpm's/light load, it doesn't seem to happen very often.

The CEL does come on after a few minutes of this. I've got a code scanner. Here's what it says:

P0300 - Random/Multiple Cylinder Misfire detected.

Well, duh.

Background
It's a 2002 Protege5, 85000 km on it. I got it used 3 months ago from a Kia dealer. No service records from previous owner. I had no problems with it the first 3 months.

About 3 weeks ago I took it on a road trip, including 5-6 hours of driving on dirt roads. The car handled it no problem, but on the way back this problem first appeared. My initial diagnosis was a clogged air filter, and sure enough, when I pulled it out it was black as night. I banged it out against my shoe, then bought a new one 30 km later. Made it home without the problem reappearing.

Then it started happening again a few days ago. The problem is obviously not entirely the air filters fault.

Ideas:

Spark plugs? Wires? Distributor? Fuel Injectors? Fuel Pump? Something else entirely?

I don't have a garage or driveway to do any wrenching myself in, but if you think it's a straightforward problem I can go over to my parents place and do it there.

Thanks for your help and ideas in advance.
 
Mine did the exact same thing. And it was very unpredictable, but seemed to get worse. More frequent.

I would lose power, it would stall if I pressed in the clutch, but would eventually correct itself in a few minutes. Or I would restart the car and it would be fine again for a while. Really smelled like eggs too.

I replaced the plugs, still happened. Then the coil-packs, no more misfires.

I got the cheap ones from rockauto.com and they've been great for 30k so far.
 
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Replace the plugs first. When the air filter gets clogged it can directly affect the sparkplugs and wear them quicker. Don't ask me why...used to happen all the time on offroad motorcycles when I worked for a dealer.
 
i12drivemyMP5 said:
Smells like coils to me...............
Click to expand...
Thats a big ten-four! If you are doing this now-->(drive) change your plugs, wires, and coils. Then you should be doing this-->(drive2) I always start with the cheapest stuff to replace, then work you way up to more expensive....
 
Another set of coils and/or wires gone bad in the 50,000 to 60,000 mile range. Mine werent bad yet but I replaced mine anyway a couple weeks ago because I was in that range.
 
Ok, replaced the plugs. Problem's still there. Coils and wires are on the way.

One thing: The plugs were quite black on the end - all 4 of em. Sooty, not gummy. Is that what I should expect from having repeated misfires, or is that an indication of a larger problem?
 
Are you eating any fluids? Mine feels like it misfires too sometimes. The P5 does NOT have a fuel filter in-line also. It just has an in tank "sock" style. I have come this close to installing one myself. Bad gas can give you a mis-fire. If you have the money, run a tank of mid or premium grade through it. It will help burn off some of the crap buildup. And if it stops misfiring, its a compression issue. Check your PCV valve also. Then see if all your vacuum lines are working properly.
 
Robotman said:
Hey guys, I was wondering if I could get some help diagnosing a problem before I take it in the mechanic.

The problem:

A sudden loss of power, typically at mid-to-high RPM's, under load. The problem first happens quite faintly, barely noticeable then progressively gets worse over the next few minutes. Under low rpm's/light load, it doesn't seem to happen very often.

The CEL does come on after a few minutes of this. I've got a code scanner. Here's what it says:

P0300 - Random/Multiple Cylinder Misfire detected.

Well, duh.

Background
It's a 2002 Protege5, 85000 km on it. I got it used 3 months ago from a Kia dealer. No service records from previous owner. I had no problems with it the first 3 months.

About 3 weeks ago I took it on a road trip, including 5-6 hours of driving on dirt roads. The car handled it no problem, but on the way back this problem first appeared. My initial diagnosis was a clogged air filter, and sure enough, when I pulled it out it was black as night. I banged it out against my shoe, then bought a new one 30 km later. Made it home without the problem reappearing.

Then it started happening again a few days ago. The problem is obviously not entirely the air filters fault.

Ideas:

Spark plugs? Wires? Distributor? Fuel Injectors? Fuel Pump? Something else entirely?

I don't have a garage or driveway to do any wrenching myself in, but if you think it's a straightforward problem I can go over to my parents place and do it there.

Thanks for your help and ideas in advance.
Click to expand...

I've had the same problem. the spark plug wire literally broke andI had change them. then the problem was still there, even after I change the plugs. I took mine to the dealer and it was a misfire in the 1st cylinder. so pretty much the spark plug was re-torqued and it doesn't seem to misfire anymore. but now, I find myself checking the spark plugs and wires periodically.
 
thrasher said:
Mine did the exact same thing. And it was very unpredictable, but seemed to get worse. More frequent.

I would lose power, it would stall if I pressed in the clutch, but would eventually correct itself in a few minutes. Or I would restart the car and it would be fine again for a while. Really smelled like eggs too.

I replaced the plugs, still happened. Then the coil-packs, no more misfires.

I got the cheap ones from rockauto.com and they've been great for 30k so far.
Click to expand...
what is a coil pack and where is it located/ look like?
 
P5inMD said:
what is a coil pack and where is it located/ look like?
Click to expand...

The coil packs are the two little black boxes that sit directly on top of your valvecover, right on the tip top very middle of your engine. They each sit directly over a spark plug. Each have one rubbery wire (the spark plug wire) coming out of them and have a couple regular wires plugging into them as well, with a connector.
 
thrasher said:
I would lose power, it would stall if I pressed in the clutch, but would eventually correct itself in a few minutes. Or I would restart the car and it would be fine again for a while. Really smelled like eggs too.

I replaced the plugs, still happened. Then the coil-packs, no more misfires.
Click to expand...

Yeah, this sounds identical to what's been happening to me. I'm fairly optimistic new coils & wires will do the job.

thejetman said:
Are you eating any fluids? Mine feels like it misfires too sometimes. The P5 does NOT have a fuel filter in-line also. It just has an in tank "sock" style. I have come this close to installing one myself. Bad gas can give you a mis-fire. If you have the money, run a tank of mid or premium grade through it. It will help burn off some of the crap buildup. And if it stops misfiring, its a compression issue. Check your PCV valve also. Then see if all your vacuum lines are working properly.
Click to expand...

Fluids seem fine. Oil level was high when I checked the dipstick while replacing the air filter. When I got it changed last week at a Jiffylube, they didn't comment on the oil levels then. They replaced the PCV valve at the time as well. It was fairly dirty, again likely from my off-road excursions.

I'll try the fancy-gas too when I swap the coils and wires.

Thanks again for the advice guys.
 
Robotman said:
Yeah, this sounds identical to what's been happening to me. I'm fairly optimistic new coils & wires will do the job.



Fluids seem fine. Oil level was high when I checked the dipstick while replacing the air filter. When I got it changed last week at a Jiffylube, they didn't comment on the oil levels then. They replaced the PCV valve at the time as well. It was fairly dirty, again likely from my off-road excursions.

I'll try the fancy-gas too when I swap the coils and wires.

Thanks again for the advice guys.
Click to expand...

A quick test would be to swap your 2 coil-packs. The CEL code should change because now you'll be misfiring on a different cylinder.
 
Ugh. Still happening. Replaced the coils and wires. Now I think it might be something different.

To recap, here's what's happened, some new notes, and my new theory.
The problem: a loss of power & shuddering, that progressively gets worse.

First occurred after a road trip on some dusty roads. Tank was 1/3-1/4 full when I noticed it. Initial suspect was a clogged air filter. Cleaned the air filter and filled the tank and the problem went away.

Next occurred 2-3 weeks later, again when the tank was 1/3-1/4 full. This was when I made my original post above. On the advice of you guys I replaced the plugs. Problem was still there. Someone suggested putting in some premium gas. I did so, and the problem went away.

The new coils & wires I ordered show up, and I replace them. Still no problem. I am happy.

Today, drove ~100 km without a hiccup, until I once again dipped down to 1/3 a tank. Problem happens again. "****," I exclaim. I fill up when I get a chance, and the problem goes away again.

__

So, am I correct in guessing that it's probably something wrong with the fuel pump?

If so, what would be your estimate for a total repair bill if I take it in to a Mazda dealer or an independent mechanic?
 
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change it yourself, the access hatch is under the back seat cushion and its only a few bolts and plugs. make sure u replace the strainer with the pump or you will just have more problems
 
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