toxdoc1947

I have a 95 SC4 with 122,000 miles. Just had 120,000 mile maintenance (3 weeks afo). I've noticed that the car has an irregular miss at medium rpm (40-50 mph). The miss isn't there at higher speeds.

If this happened to my trusty MGB, I'd say it was plug wires.

Any thoughts anyone? Has anyone changed plug wires on a SC4? How difficult is it?

Thanks

Nick T

toxdoc1947m
Plug wires are a good place to start. Sounds like you've taken your car to the dealer ??? "120,000 mile service" The dealer NEVER changes the plug wires for a service so you might be due. I reccomend changing the wires every 60k or even 30k miles along with your plugs. They are not hard to change if you buy the OEM dealer stuff which comes with all the tabs and seperators. No experience with aftermarket. Although I'd love to put some 8mm or 8.8mm wires in ... somehow.

Regards

toxdoc1947

I think messing with MG's for all those years has helped. I asked the dealer to quote plug wires: 129.00

Purchased and had them shipped from a dealer in Califorma for less than $100

jtlockyer

I have the same problem, also with a '95 SC400, but I have 230K miles on it.

I seem to notice it mostly when the engine is nearly warmed up (been driven for two minutes, but not up to normal temp). I notice it mostly go to and from work on surface streets before I hit the freeway.

It seems like I can lessen the problem by pressing down on the gas pedal or releasing the overdrive. It is almost like driving a manual transmission vehicle in four-gear and trying to accelerate up from 20mph (that's why releasing overdrive seems to help).

I looked at the left side of the engine's plugs and wires a month ago, but they looked excellent.

toxdoc1947

I bought some OEM sparkplug wire and replaced the old ones, which had apparently never been replaced.

All wires met the resistance specs with resistance < 15 ohms, but in some had deep cracks in the insulation.

Handling and response is much better. The mid-rpm misses are gone.

By the way, I'd never have bneen able to do the ignition wire exchange if I hadn't had the DIY instructions from the list. Thanks a bunch everybody!