Momentary Loss of Power

[funkytuqe]

Hey Guys, i seem to be having a minor issue with my 03 P5. When driving along, the car will completely loose power for an instant, then kick back on and everything runs fine. It feels like a misfire or something. I get no CEL, and everything is running great, mileage is still good. This happens 4 or 5 times per week to me. This started happening after my header installation, so I'm not sure if it is just coincidence or if it is related somehow to the non-fouler or something.

The car has 125000KM, all regular maintenance is up to date, new spark plugs less than a year ago (maybe i should check my plug gap? what is the gap spec?). Could this be a sign of one of the coil packs going out? I have new plug wires in the Garage, I'll might as well put them in.

Any advice?

 

[thecrash91]

could be packs or wires. id try packs first, then wires, check your hoses etc. make sure you have no leaks, then clean MAF if all else fails

 

[funkytuqe]

Thanks, this one is tough to nail since it is so random. I'll get some new coil packs, check my plugs, replace the wires and see what happens.

 

[hornsfan10609]

stock plug gap is ".044, not sure what that is in mm

 

[thecrash91]

yeah its weird that its ever so often. also kinda makes it suck to test because you have to wait so long to see if what you did was affective

 

[P-Funk!]

Try wires first.

 

[ucMP3]

I would bet $$ that it's the coil packs.

 

[slavrenz]

I would bet $$ that it's the coil packs.

+1. They always seem to go bad before the wires.

 

[thecrash91]

+11

i speak from experience, although wires went about 1k miles after i hanged coil packs, goes to show that wear and tear will travel the path of least resistance, therefore by chain rule wear and tear=water

 

[streetboi]

couldnt it be the fuel pump failing?



edit:

didnt notice you lived in calgary. I live in airdrie.

 

[zephyr911]

I had a similar problem occur 2-3 times in a single drive, several days ago. Fuel pump was my first thought. I'll have to follow this thread and see what my car does.

 

[drgnzadiel101]

coil packs for sure. had it happen to me and no cel either. went to autozone, bought some replacements...been running fine ever since.

 

[MaxPower]

Check the battery terminals and make sure they're clean. Poor contact between the battery cables and the battery posts can cause intermittent loss of electrical power.

 

[ucMP3]

Check the battery terminals and make sure they're clean. Poor contact between the battery cables and the battery posts can cause intermittent loss of electrical power.

What? That wouldn't affect the car making it lose power while the motor is running. If the alternator is operating properly, the battery can be dead...

 

[funkytuqe]

Thanks guys, i did not have time to look at i this weekend, i think i'll just replace the coil packs and see what happens.

Good call on the fuel pump, i guess if new coils does not fix it then i, try the pump next.

 

[slavrenz]

Thanks guys, i did not have time to look at i this weekend, i think i'll just replace the coil packs and see what happens.

Good call on the fuel pump, i guess if new coils does not fix it then i, try the pump next.

i would insert an intermediate step in there:

"Get a fuel pressure tester and make sure the pump is actually bad"

You don't want to start playing the "just throw parts at it" game - this usually ends up badly and very expensive.

 

[AusOrion]

I would have though that a dodgy coilpack would mean you only drop cylinder (or two) and not lose complete power???

I like the direction the battery was going. Any thoughts on whether it could be something like the regulator for the alternator?

 

[ucMP3]

I would have though that a dodgy coilpack would mean you only drop cylinder (or two) and not lose complete power???

I like the direction the battery was going. Any thoughts on whether it could be something like the regulator for the alternator?

Per the first comment, the thread's name is "momentary loss of power" aka a misfire...

The battery going out will not affect power while the motor is running. The alternator can cause some screwyness, but it won't cause misfire-like symptoms.

 

[funkytuqe]

Yah, it's more like a misfire. Sorry for the confusion. The car will stutter for an instant, one bad coil would mean two cylinders not firing properly. When it happens it can sometimes be a little harsh and the car will buck once. I had it happen at idle once, the RPM's dropped close to 0 for an instant then it came back alive and recovered by itself. I would assume that a bad fuel pump would cause more issues when the motor is under load, so i'm guessing it's probably one of the coils.

You know, i may check the battery terminals too though, i just finished a stereo install 3 or 4 weeks ago and maybe i forgot to tighten the terminals on the posts or something. I may check the chassis ground in the engine bay too. I have had no issues starting it though, it turns over just fine.

 

[AusOrion]

Yah, it's more like a misfire. Sorry for the confusion. The car will stutter for an instant, one bad coil would mean two cylinders not firing properly. When it happens it can sometimes be a little harsh and the car will buck once. I had it happen at idle once, the RPM's dropped close to 0 for an instant then it came back alive and recovered by itself. I would assume that a bad fuel pump would cause more issues when the motor is under load, so i'm guessing it's probably one of the coils.

You know, i may check the battery terminals too though, i just finished a stereo install 3 or 4 weeks ago and maybe i forgot to tighten the terminals on the posts or something. I may check the chassis ground in the engine bay too. I have had no issues starting it though, it turns over just fine.

If it is a mis-fire then coil packs are a good place to start.

Sorry, when I read "loss of power", I kind of took as there was no power what-so-ever coming from the engine.

Hope you find the solution soon.