Carib

Help needed.

Tonight, my 92 SC400 (212,000km) was working like a charm. Drove to a banquet hall and had no issues with it. After about 4hr (when everything was over), the car started up as normal... I drove no more than 100meters when it started idling rough, started sounding like a tractor, and just simply wouldn't go...

The following was happening:

- Rough idling (between 400 and 700 rpm) when in Neutral
- When in gear, it idles rough between 600 and 800 rpm
- Does not accelerate quickly...that is, it sloooooooowly gathers speed.
- Tachometer drops down to 0 rpm when gear shifts from 1st to 2nd
- when it neutral, the engine won't rev more than 1500rpm (don't think the tranny is the problem)
- burning smell coming somewhere from the engine bay or underneath the car
- Engine oil and coolant levels are good.
- Engine is not overheating (according to the temp gauge)

Due to it being 1:30am and wearing a suit, I couldn't do much troubleshooting. The car is sitting on the side of the road at my uncle's house. Will have to get it towed home if I can't fix it... don't want to risk driving it in that condition...

Would really appreciate any possible theories/advise for when I go later this morning to check what's wrong with it...

Jinx2006

I would check the serpentine belt area, as well as your pulleys. Sounds like maybe one of them froze up on you. This is a common problem, but hard to pinpoint if it would be the bearings in the pulleys or the pulleys themselves. Just a start!

sean9975

could be coil packs?

Carib

Will check the serpentine belt. No noise was heard to indicate a bearing of some sort was seized when the trouble stated. The Engine seems to be running fine (other than the rough idling) when in neutral.

Coil packs, I'll have to check those...

Okay, I'm off to the car....

Thanks for the suggestions and keep them coming.... I'll be back in a while.

Jinx2006

Don't forget to check your pulleys, especially your crank pulley. Run a chalk line over the belt and pulley and see if it's slipping. Sean9975 may be right as well, could be something electrical. Keep us posted.

vwynn

iTrader: (4)

agree with coil and cap n yea..

o and the burning smell is prolly from the cats turning red.

Carib

After towing the car home yesterday, I was able to work on it with good conditions...i.e enough light, and in a covered garage.

Listening to the car is sounded as though it was misfiring (or lack of) and the exhaust fumes were smelling rich... I didn't let the engine run long enough for the cats to get hot, but just long enough to test the coil packs.

Started with the driver's side (easier to access)...
Disconnected the spark plug wires from the distributor one at a time and there was no change in the engine's idle. Disconnected the wire going from the coil to the distributor...no change.

Did the same test with the passenger side... instantly noticed a change in idle when any of the spark plug wires were removed and the engine stalled when the wire going to the coil was removed.

99% sure the driver's side coil pack was the problem.

Tested the resistance of the coil pack....

Apparently, there's supposed to be 0.4 to 0.5 ohms across the + and - terminals... and 10Kohms to 15kohms between the + terminal and the high tension terminal (the one that goes to the distributor).... I was getting 0hms across the terminals and also to the high tension terminal.

100% sure the coil pack is the problem now...

Going to replace the coil pack tomorrow when the part comes in at the dealer.

Thanks for the quick advise earlier...

Latahs.

SClean4

I think I'm having the same problem, the slow initial acceleration, car sputtering physically on occasion where the car will jerk/rock a little bit when you try to begin acceleration then will gain speed and be fine.

vwynn

iTrader: (4)

if u have alot of milage on the old coilpack and plugs that are working.. might as well change out everything =]

Carib

Yup... changed out the driver's side coil pack and the car started up, idled smoothly, and is now able to be driven without any issues.

Don't know if it's my imagination or if it's really happening, but the car feels a bit more responsive and it seems that I'm getting getter mileage. I'm keeping an eye on that one...

I'm glad to have the car up and running now....

Latahs.
Carib.

CLRH2O

Wow - so I guess coil packs just...... go. Like that. Boom , in a flash, instantly and without warning. One moment all is good.. then literally the next - poof!, done.

Marked in my mental locker for the future if this ever happens to me and my SC400 (1993).

sean9975

yea i drove my car in to my garage with no problems, after we finish body work & paint. 1 of my coil packs was causing my pre cats to overheat. so naturally i thought they were clogged. nope packs

RandySC400

What do you mean "Nope Packs"? my cats turned red after i change a coilpack and my plugs.... Precats???...Help me I'm confused

lexhere27

I had the same problem on my 92 SC400 and I unplugged each coil individually. It idled fine with the drivers coil but stalled out with the passenger coil. I installed a new coil last night and it ran like normal. Just thought I'd pass on my information and say thanks CL for the search button, it does work.

mr/griffin

sounds like plug boots leaking oil into cylinder check that!