97 RS 420a NT Manual

Car just started cutting out upon acceleration. Misses like it's starving or flooding. It's worst from a dead start and at low RPM's, especially if I use any throttle.

At low (1500-1800)RPM if I quickly push the gas about 1/2 way down I get a backfire up front like in the headers. (that's what it sounds like anyway)

This happens only under a load. In neutral I can gun it from idle on up effortlessly. Also, after taking off, if I keep the tach over 3000 I can run WOT in between shifts if I want to.

Any help greatly appreciated. I'm going outside now to check out whatever I can. i.e. plugs, wires, CAI... Thanks guys!

Ok, the plugs, wires & coil pak are fine. I didn't think it was electrical. What should I check next?

Originally posted by Nemo
Ok, the plugs, wires & coil pak are fine. I didn't think it was electrical.

I did ;-)

Check map? Do you have a fuel pressure gauge on by any chance? Any weirdo fluctuations (if you do)?

I have a scan gauge, I'll check. Thanks

Originally posted by Nemo
Ok, the plugs, wires & coil pak are fine.

Double check the plugs and wires again, b/c what you are experiencing can be isolated to those two items 99% of the time.

Next, move on to fuel filter

Backfire in exhaust means your too rich.....backfire in intake means your lean

That sounds right. Thanks. I still think it's in the exhaust. What might be the cause of running rich?

BTW, I'm not throwing any codes, the upstream sensor is new too.

Thanks, Erik. I'll get a meter tomorow and check them again.

Ok, I want to order a coil pak. An OBX is $52 shipped. Makes the same claim as MSD which I couldn't find for under $60+shppg. Is there any preference?

OBX also has wires for about $55 shipped. That's the biggest coppers I can find.

I want to put a ground kit on. Just seems like a good idea. I'll most likely buy one. Starting school soon.... I'll post what I can soon too.

Thanks.

Hell, I prefer stock.

Lol, I just ordered a MSD. It'll be here Thur. It ended up being cheaper than Duralast, OBX, Signal,(never heard of Signal before), and satan.

My car's getting worse. I'm not driving it more then necessary now. I noticed one terminal on the coil shows signs of arcing/burning. Geez I sure hope it's the coil and not the ECU.

Mine had a arced/burnt terminal on it too. It never caused me a problem physically but i do think it manifested itself in an uber choppy dyno graph, so i wouldn't worry about it too much. I think it had something to do with a torn boot in the spark plug wires...that reminds me i need to change them...

I'm replacing the coil and wires tomorow. I have a fuel pump on the way and will do the filter while I'm at it. I wander hundreds of miles from home in this thing ocasionally.

You should check your catalytic converter. If you can get a back pressure tester (its really a pressure gauge and a special tool that threads into your pre-cat O2 sensor hole) you would be able to figure out if its plugged. If you stab the throttle from idle till 6500rpms and your readings are 1 to 1.5 psi you might want to get a new one.

Just a thought.

Thank for the tip Yo. I'll certainly put that in my what next list.

The problem was the coil all along. I replaced it with an MSD one along with the plug wires.

Good thing you decided on MSD. I wont buy OBX anymore after my experience with their fuel rail.

Yeah, I'm happy with it already. Put on their wires too. OBX coils are round pin only and I had a flat pin connector. That caused my decision, lol.