View Full Version : My 93 SC is falling on its face

02-15-2008, 04:23 PM
I am a new SC owner and I believe that mine has been severely abused during it's lifetime. It runs rough, the front shakes and no one seems to be able to figure out why, I've fixed numerous cosmetic things and I know we still have a long way to go.
Recently it began simply falling on its face from time to time. I'll be cruising down the road at 45 or so and it just chokes, as if running out of gas. Sometimes its only a slight sputter, but other times it almost brings me to the side of the road.
I know this could be numerous things (supercharger going out, Mass airflow sensor, fuel pump) and I received a bleak pre-diagnosis diagnosis from my mechanic. I was hoping that someone out there has experienced this and has better news or ideas for me.

Also, if it is the supercharger, what years are compatible with 93?

02-15-2008, 04:28 PM
All model superchargers should be compatible if you get the inlet plenum with it. The 94/95 superchargers will give you better power though. It really doesn't sound like the supercharger is bad to me though. If I had to guess I would say fuel filter or fuel pump is the most likely cause.

fast Ed
02-15-2008, 05:39 PM
Supercharger shouldn't be causing any issues at a steady part-throttle cruise ... more likely to be igntion or fuel related.

Ed N.

02-15-2008, 05:43 PM
I would start with the basics first before you start chasing costly items. Things like getting new proper set of spark plugs, and spark plug wires. As mentioned a fuel filter as well. Essentially give the ole girl a full tuneup so you know where that is with the car.

Included with that tuneup, I'd pull the DIS off and clean the white paste off it which is a heat sink compound, not Dieletric grease. Clean both surfaces very well, then apply new compound very lightly and gently tighten the DIS down. (volunteer's to write up a good tune up document ;) )

The superchargers in our cars a very hardy lumps of metal, and rarely fail... unless your (man I forget his name) where he insisted on trying to spin the snout as well as the pully ;).

02-15-2008, 05:48 PM
Your supercharger is not causing this problem. Best thing to do is run some codes as this car will tell you what is wrong 90% of the time. Do a search on running codes. If it is fuel related start with the simple and cheap. Fuel filter and have your fuel pressure checked before replacing pump but these cars are 15 years old and fuel pumps have been known to go at 10 years (most common) but some never go out. This could also be DIS. there is a heat sink compound under it that keep it cool and if it over heats you have problems like you discribed. Alot of people take the intercooler pipes off and dont reseal them or dont allow enough time for the sealant to cure and this will cause bad idle and give you under 20 inches of vac. Spark plugs and wires are also a problem. I have seen cracked coils (under), bad balancers, faulty crank sensors, plugs,wires, fuel, loose or corroded or burnt wires around the engine. Dirty maf, just to much to list but do the code test first and make sure you know it well. Read it ten time if you must because every step is important.

02-16-2008, 01:44 AM
my sister has a 97 lx V-6 and her car was shaking intermittently and then idled really ruff and then fine and kept getting worse till it barely went anywhere and we tried a coil pack since it came up with engine miss codes and it ended up that the computer went bad and put the car in limp mode. So if youve tried everything else maybe see if you can get your computer tested or swap it with another one, just a thought

02-20-2008, 05:41 PM
My girl is at the mechanic today. Of course, she won't act up and he isn't getting any codes. He still insists it is the mass airflow sensor. From what I can tell, very easy to replace so I think I'm just going to bring it home and take your suggestions....a thorough tuneup. Thanks everyone.

By the way...please forgive my ignorance, but what is the DIS?

02-20-2008, 06:08 PM
Distributorless Ignition System (DIS)

Many of today's vehicles are equipped with D.I.S. or distributorless ignition systems. These vehicles do not use a distributor. In place of the distributor they use sensors to fire an ignition coil pack. There are two styles of ignition coil packs. The first type of coil pack has all the coils mounted on one mounting pad. If any of the coils are found to be defective, the entire coil pack must be replaced.

The second type of coil pack has all the coils mounted individually on a mounting pad. On this system, if one coil is found to be defective, it may be replaced as a separate unit. Testing procedures on these coils are the same as the procedures described earlier. As always you should refer to a specific automotive service manual for details and specifications on your vehicle.


02-20-2008, 06:24 PM
I had a problem like that with mine. The guy I had bought it from had dropped the fuel tank and busted the connector for the fuel pump. That let in water and then I had corrosion problem causing a bad connection from time to time.

02-22-2008, 03:41 PM
As a new SC owner, I really appreciate the help and all the great advice. My SC hasn't acted up since I picked it up from the mechanic yesterday and he couldn't get it to act up in the two days he had it (of course). He said the plugs and wires look good. So I'll leave those alone.
I'm going to just start going through everyones suggestions and hopefully it will be something really simple, like the fuel filter.
Thanks again everyone.

02-22-2008, 04:48 PM
Take her to the local scrap yard and show what will happen to her if she keeps acting up......:p

02-22-2008, 07:29 PM
my 95 was doing it under mild acceleration, and changing plugs fixed the problem. :)