87 Brougham misses on hills and over 50mph

[Broughamfanatic]

I replaced the spark plug wires, distributor cap, and rotor myself on the car. I even set the timing to 20 degrees like the sticker says (with the ALDL connector grounded to set the base timing). I am absolutely sure all the wires are routed correctly. Now, when going uphill or cruising over 50mph, the engine misses. It feels more like the transmission torque converter is engaging/disengaging every 5 seconds. But, I took it to AAMCO and the guy said it wasn't the transmission, but the engine. The funny thing is, in PARK, when I rev the hell out of the engine it doesn't seem to be missing at all. I removed the cap to see if there were any carbon tracks from arcing or whatever. It looked fine. My gut tells me it's the transmission. But, on the other hand, the expert said it wasn't AND none of this happened until after I messed with the above mentioned parts.

[guidematic]

You did not replace the sprk plugs. This could be the problem. They may be breaking down under load. This can cause a shudder or miss similar to the condition you are experiencing.

Replace them with AC/Delco FR3LS6's (new number is 41-611, I think) and gap them to 0.060".

Mike

[90Brougham350]

Plugged catalytic convertor. Good luck!

Brian

[Broughamfanatic]

You know, that could be it. 18 year old plugs with 38,000 miles on them getting their asses kicked by the new ignition components. I'll have'em R2D Monday I guess. I would do it myself, but I'm not in the mood to bust my knuckles and get hand and back cramps trying to reach the plugs on the right side of the engine. Thanks.

[guidematic]

18 years old? Man I'd be getting them outa there and some new ones in a hurry! But be careful not to break any. They may be seized in.

An easy way to do the front 3 on the right is to jack up the car and do the through the wheel well. Use a flex socket and a long extension.

Mike

[N0DIH]

I prefer 1/2" drive, it has much more control and power on plugs. Craftsman has them.

[Broughamfanatic]

It was the #5 spark plug wire! Those things are practically new! I must have kinked one or did something to it when I was installing it. I got the plugs done yesterday and still no change. So, this morning, like dog with its tail between its legs, I walked into the mechanic's shop and asked if he could fix what I broke. He said #5 was misfiring 'under load' which explains why it seemed to run fine in PARK. And I thought it was my torque converter clutch.....but she runs like a champ now!

[guidematic]

Great! Glad to hear you found the problem. It's nice when it's something simple, embarassing or not.

BTW, what did those 18 year old plugs look like?

Mike