Hello everyone. I haven't been in the forum for a while, to busy I guess. I have a long and involved ignition system problem. I got the car in march of last year and it showed up about a month later, and I have been dealing with one thing or another on it since then. Apparently a fiero isn't the best car to get when going to college.
He is an explaination of what I have observed and replaced on the car to date. All parts were either from Champion or Checker if that makes a difference.
4/03 Distributor Cap and Rotor replaced ( had moisture in it )
5/03 Noticed that the car would miss slightly and the tach would jump if you got on it directly after a cold start, but would be fine after it warmed up. So I ignored it and didnt' think that much of it.
Then the voltage regulator in the alternator went bad and put out 18-20V
The Ignition Module died while driving because of alternator
A couple days later I was sitting in the car for about 30 minutes with the key on but the car not running ( replacing speakers ) I got out of the car and saw slight smoke coming out of the engine bay. I opened it up and it was coming from my coil. I have no idea why it would be drawing current while the car wasn't running so I replaced the coil, pickup, and the problem went away. Spark plugs and wires were also replaced at the same time.
6/03 Diode in alternator went bad. Alternator replaced again.
10/03/03 Engine was running fine all summer went to start the car in the morning and ignition module was dead again no signs of misfireing or alternator problems this time.
New ignition module (2nd)
11/03 Tachometer started to jump more on cold starts for first 5 minutes or so. Engine would miss when the tach jumped until it warmed up. When warm the tach is fine and the engine never misses. You would never know that it had a problem if you drove it when warm.
11/30/03 Went to start car in the morning and Ignition module dead again
New ignition module (3rd)
12/03 Starting problems. Have to crank the engine for ~15secs before it would catch at all. When it finally caught it has a rough idle around 2000rpm while in the cold start mode.
When the engine drops down to the normal idle it runs rougher sometimes dies. It now takes longer to warm up but will eventually run fine.
1/04 I replaced the fuel filter and the starting problem didnt' change. I had a neighbor hook it up to his computer in his shop. It's not setting any trouble codes and the only thing that he saw out of place was the tempurature sensor.
Tempurature sensor replaced. (Problems didnt' change.)
**O2 Sensor does not stay steady at a constant idle it jumps around from 50mV to 900mV I haven't replaced it because the car does run rich and it could actually be jumping around that much?
I had the car running and shut off the lights to see if anything was arcing. I saw two spots that would light up as the engine missed. The first was inbetween the square part and the round part of the ignition coil and the other one was the plug wire that goes from the coil to the distributor cap. (at the cap end).
Replaced the coil with a new one and there was no change seems to be a side effect not the cause.
I was at a loss after 6 months of this problem so I broke down and took it to the local pontiac dealer. They were optimistic at first because they thought they found an internal short in the ecm. They ran some more tests the next morning and decided not to change the ecm because they didnt' think that was the cause anymroe. As of now they have about 5 - 6 hours ($300) of diagnostic charges but no answers at all. They replaced the coil, ignition module, carb?( the service consultant said carb but I dont' know what he meant by that) with known good gm parts and the problem persists.
I told them to pack it up monday morning and I'll take it home. If you guys can think of anything to help or have them look at while it's still there let me know. ( firstname.lastname@example.org )