metalmike6

Hey all,

I'm really hoping some one can help me figure out what the hell is going on...

So my car was running completely normally until today. I don't know if it matters but today was the first hot day where I live and the first hot day the car has seen since I gained ownership of it. The temp gauge was dead center while I was driving it as opposed to 1/4 the way across like it has been all fall/winter.

So after getting home I noticed a pretty strong gas smell coming from the car. I looked for leaks but couldn't find any. So I started the car up again and realized the smell was coming from my exhaust. It's never done that before. But I figured maybe it was because it was hot. So about 2 and a half hours later, I started the car and immediately noticed my check engine light was flashing rapidly. It won't stop. Even when the key is turned but the car is NOT started it still flashes. The other odd thing I noticed this time starting the car is a higher then usual idle? In addition to this a strange whine from under the hood. I can't pin point it exactly but it sounds like drivers side towards the windshield.

If you guys need any more information let me know. I will be monitoring the site like a hawk for a response so just ask and I will answer. I really appreciate any help you guys can give me as money is tight right now and I'm just hoping I can pull off the labor myself.

**Update**
So the issue went away when the car finished cooling down completely. I restarted it and the light was still flashing after about 30 seconds of idling the SES light turned off... As I pulled out it came on again for about 10 seconds and finally went away again. It should be noted that when the light turned off the idle of the car changed as well. (Limp home Mode?) It almost seems as though something might be loose. But I have no idea where to even start looking? If anybody has any idea's at all I would truly appreciate your knowledge, thanks again.

metalmike6

Any Idea's guys? I'm thinking O2 sensor, but I'm not sure?

Vader

It's not an O² sensor problem causing the MIL to flash. The ECM is complaining about the PROM, incorrect voltage, or connections. The engine was probably running on the backup parameters ("limp mode") and was therefore extra rich.

It's fairly easy to drop the ECM from the passenger side dash to check connections, reseat the PROM and MEMCAL, and test for input voltage.

metalmike6

AWESOME a response! hehe, thanks - I'll check that out in about 5 minutes literally, for the record the damn thing started flickering again... What should be proper voltage (12v?) I mean being a computer guy I know most boards are very low voltage like 1.5v or 3v but usually there is some kinda of regulation dropping down a higher voltage.

squirted1

iTrader: (2)

You mentioned a higher idle and strange whining noise, have you checked for a large vacuum leak, possibly the booster feed or the booster itself?

metalmike6

I have not checked for a vacuum leak, I thought the whine/almost a whistle may have been that as well but wasn't sure 1.) Where said booster or feed is located and 2.) wasn't sure if that would even cause the check engine light to go crazy.

I should note I am new at this, there is so much I want to do to my car, but I haven't the knowledge (and money...yet) I've been trying to learn as much as I can from the forum. So I guess I could say I have a bunch of theoretical knowledge but I don't know what the hell some of this stuff even looks like? Ha, I get points for trying though right. I think the Vacuum booster is in the front drivers side of the car near the headlight... But I could also be a complete jackass?

Vader

Actually, it's really only desktop and laptop PCs which use 3 or 3.3V. Most other processors use 5VDC, as well as the CMOS and TTL support firmware and I/O. Automotive systems use a 12V input, then an internal regulated supply for the 5VDC used by the processor, I/O, and RAM/ROM.

Just be sure there is a sustained 12VDC to the ECM and that there is NO ground resistance on any of the ground connections to the ECM. Some are chassis (noise) grounds, others are for power, and others are for signal reference. Differences in potential between any of those grounds will cause problems.

Since it is happening even with the engine off, the possibility of an alternator problem (a major suspect in rogue ECM problems) is not an issue.

squirted1

iTrader: (2)

the power brake booster is located directly behind the brake master cylinder. It is fed engine vacuum from the hose that is connected to it that goes to the intake manifold or carb on whatever system your vehicle is running.

Ward

iTrader: (1)

Is this an 86-89 TPI car? My ECM memcal socket turned out to be bad (probably a bad solder joint somewhere, a common problem with '165 ECMS), and I was having a similar problem. I finally figured out that was the problem because (with the ECM unbolted and laying on the floorboard) I could press down on the memcal, and it would work fine. Otherwise, the SES light would flash like mad.