pbfrench

1998 A4 Coupe, I want to start with apologizing for the fact that I do now have codes to share and the car is now 300 miles away and I am needing direction as to what I should be checking. As stated in the title, the coils, plugs, plug wires were all replaced as well as the oil changed. Upon starting the car initially after replacement, all 8 cylinders were firing. as the car warmed up a miss became noticeable and upon checking the whole passenger side bank was now not firing. Could not find anything visually and was on a time crunch to get out of town so I was unable to check any codes. Any ideas on what check or what the problem might be? Ground? ECM? (Battery was disconnected while changing coils).

Thank you in advance for any insight you may have.

feeder82

Forgot to plug harness in for that bank of coils or broken wire to that side?

pbfrench

Connectors were all connected. Wiring harness felt a little brittle. Code P0300 HC was present before and after clearing codes. U1064 was present before clearing but did not come back. Also had code ( I don't recall the number) that said something to the effect of HO2 sensor bank 2 low voltage. After cleared it did not come back. All other codes were related to either the TCS ( LR wheel speed variation due to connector) or TPS System because the batteries are dead in the wheels.

73Corvette

Ground makes sense... I would go back and trace my steps carefully and look for something that I overlooked...

SaberD

check your fuses for the injectors and ignition inside and under the hood.

lionelhutz

Besides just the injector harness, makes sure the main engine harness is not shorting out against a bracket or other sharp edge possibly on the fuel rail brackets.

SteveDoten@ARH

The 97/98 are unique in that each coil is bolted directly to the valve cover. With that being said, I can't recall if they have the individual harness for the 4 packs on each side that can be swapped out on the coil pack bracket (set of 4) that are on the 99up cars.

Swapping the coil harness from R to L or vice versa would be my first step.

I'm amazed at how the wiring is still intact on these cars, most of these that I see look like one piece of 2 gauge wire that is solid under the brackets.

Speculation here: once the coil pack harness heats up, it may be expanding and causing a short, thus you have the issue only when warm.

lionelhutz

Yes, there is still a coil pack harness for each valve cover on the 97/98 cars.

pbfrench

Car is fixed.... SaberD nailed it with a blown fuse for the injectors on that side.

Thank you all for the guidance of what to check.

lionelhutz

I'd still check the wiring. Fuses usually don't blow for no reason.

Bill Curlee

LOL!! I was reading the post and thought I would NAIL it first. The Fuse was my first thought. Wonder how I know........

My 02 ZO6 would kill one bank under full throttle acceleration. Damn thing runs pretty good on four cylinders...

Here is/was the cause of the short:





The FIRST time it blew,, I thought it was just a fluke.

The second, third and tenth time it blew, I figured that there was a specific CAUSE.

If it were my car and you expierenced any more fuse issues,,, Look for a cause..



Bill