Engine Missing at 1400 RPM
Thread Starter
Intermediate
Joined: Oct 2001
Posts: 49
Likes: 0
From: Boca fl
Engine Missing at 1400 RPM
I've developed a miss in my engine. Its intermittent, when I put the engine under moderate load while in 3rd or 4th gear (A4) between about 1200 and 1400 RPM. After 1500 RPM, its fine under general driving or full throttle conditions. Any ideas on what I should look for before taking it to the dealer.
Thanks,
Mike
98 Vert
Torch Red
Thanks,
Mike
98 Vert
Torch Red
Team Owner
Joined: Mar 1999
Posts: 28,753
Likes: 9
From: San Jose/Bear Valley CA
CA Events Coordinator
Re: Engine Missing at 1400 RPM (Micky123)
plugs, wires, optispark unit can all misfire without the Computer throwing codes... Use a Hand Held Inductive pickup light to find the miss in the plug wire for starters... dyno Runs can sometimes show bad plugs, wires & coils too. Look for gaps in the run for possible problems.
vetterdstr :cheers:
vetterdstr :cheers:
Melting Slicks
Joined: Feb 2002
Posts: 2,613
Likes: 1
From: Winston Salem NC
Re: Engine Missing at 1400 RPM (Micky123)
The C5 has carbon based plug wires. I've had happen what you describe, with another car. The wires develop partial breaks inside and create intermittent missing under load. The wires often break during spark plug changes. Worth looking into.
Thread Starter
Intermediate
Joined: Oct 2001
Posts: 49
Likes: 0
From: Boca fl
Re: Engine Missing at 1400 RPM (Micky123)
I'm about to take the car to the dealer to have the problem diagnosed, but first a couple of other symptoms I've noticed which hopefully will give a clue.
1. The car does not missfire until it has fully warmed up.
2. We were able to get a backfire out of the engine today when trying to diagnose.
Other than the low rpm missfires, the car runs ok. Does not seem to have lost any power.
Any ideas?
98 Vert Torch Red
1. The car does not missfire until it has fully warmed up.
2. We were able to get a backfire out of the engine today when trying to diagnose.
Other than the low rpm missfires, the car runs ok. Does not seem to have lost any power.
Any ideas?
98 Vert Torch Red
Racer
Joined: Oct 2001
Posts: 483
Likes: 0
From: Downingtown PA
Re: Engine Missing at 1400 RPM (Micky123)
I vote for bad plugs. Just had a very similar problem. First time around I just assumed it couldn't be plugs because they only had about 8k miles on them. Go figure. Good luck with yours and please let us know how you make out.
[Modified by 01C5fan, 7:11 PM 5/14/2002]
[Modified by 01C5fan, 7:11 PM 5/14/2002]
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Brett Foote
Team Owner
Joined: Mar 1999
Posts: 28,753
Likes: 9
From: San Jose/Bear Valley CA
CA Events Coordinator
Re: Engine Missing at 1400 RPM (Micky123)
My car didnt miss until it was warmed up either. Turned out to be a bad coil. It took 3 years to figure that out... :( I was not a happy MO FO during that time frame either. :cry
vetterdstr :cheers:
vetterdstr :cheers:
Advanced
Joined: Aug 2001
Posts: 95
Likes: 0
From: Idaho Falls ID
Re: Engine Missing at 1400 RPM (Micky123)
I have a similar problem that happens when the car is cold. I hit a dead-spot in slow acceleration around 1400 rpm that sometimes causes a minor back-fire. Not sure if it is a misfire because it is very subtle but that's what it seems like. My car only has 700 miles on it. I'm hoping it goes away.
Advanced
Joined: Mar 2001
Posts: 93
Likes: 0
From: COLORADO SPRINGS Co
Re: Engine Missing at 1400 RPM (docman)
My car started having the same problems a couple of weeks ago,Today I put a set of AC Delco rapid fire 12's in it and problem is gone. :cheers:
[Modified by SPRGMAN, 7:51 PM 5/15/2002]
[Modified by SPRGMAN, 7:51 PM 5/15/2002]
Melting Slicks
Joined: Feb 2002
Posts: 2,479
Likes: 17
From: Miami Fl
I just dropped off my car at Breathless for a misfire code PO300 HC. clyinder one on scanner. I'm hoping it's something simple like a wire or plug. BTW where is the coil and how much is it usually, to replace (with labor). Does anyone know what some of the "bad things" a misfire can be? I haven't really been beating on my car, I hope the cylinder is ok
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
It sounds like you have a classic case of a bad plug or sparkplug wire. I had my headers installed and had the same problem. When you get the pop does the engine misfire. Check your dash and look for the check engine lite to flash. It it comec on and stays on and you pull up your codes you will see a (10 PCM 0300) code indicating engine misfire.
Here is what I found when I had to trouble shoot mine:
LOOKS NORMAL, RIGHT
[IMG]
[/IMG]
CLOSER EXAMINATION REVIELS:
[IMG]
[/IMG]
[IMG]
[/IMG]
On the other side I found this:
[IMG]
[/IMG]
[IMG]
[/IMG]
Your OEM wires should read between 250-750 ohms and the jackets and boots should be plyable and in tact.
Let us know what you find,
Bill Curlee
Here is what I found when I had to trouble shoot mine:
LOOKS NORMAL, RIGHT
[IMG]
[/IMG] CLOSER EXAMINATION REVIELS:
[IMG]
[/IMG] [IMG]
[/IMG] On the other side I found this:
[IMG]
[/IMG] [IMG]
[/IMG] Your OEM wires should read between 250-750 ohms and the jackets and boots should be plyable and in tact.
Let us know what you find,
Bill Curlee
Burning Brakes
Joined: Oct 2004
Posts: 792
Likes: 19
From: ME
This is interesting.... My car as well starts to run a little rough when at operating temperature - runs ok when cold. Maybe I as well have a bad coil? I'll have to check this out. (Tech 2 at work I can borrow)
