Quick Missfire

[SVX_MY_BABY]

Here's a question for you.

Yesterday I took the SVX out for a drive after it sat for just over 3 weeks. After it was warmed up I was cruising along at 50 km/h (30 mph) and there was a sudden loss of power. The tach dropped to zero and there was a clicking sound which seemed to be from the instrument cluster. I was just about to pull over when everything came back to normal. The whole episode lasted 15 to 20 seconds. Hasn't happened since.

I changed my battery a few months ago and had to recharge it after it went flat within a month. Had it tested and supposedly it's fine.

Could this have been caused by a bad battery shorting out?

Any comments welcome.

[svxnavyvet]

Alternator wires or bad ground. there is a upgrade for the wires on here.

[Noriyasu]

Are the battery terminals loose? It often happens when you change the battery

[SVX_MY_BABY]

Battery terminals are tight.

I did have the alternator changed when I got the new battery. The old one wasn't putting out what it should. Replacement is a salvaged unit. I'll have the shop check out the wires & ground next week.

[Noriyasu]

If the alternator has been replaced, it's a good idea to check the connector and B terminal for looseness. Judging from the phenomenon, it seems that all power was lost once.

I recommend that you check all points of wiring that the shop removed when they replaced the battery and alternator. I'm particularly concerned about the loosening of the ground wire.

[johnsvx]

Not quite the same issue, but I have had similar issues with battery voltage/altenator not charging the battery properly. I replaced the battery last year and the altenator this year - only to have low voltage issues a month later that affected the starter (also new) as the battery was always around 11.5 volts, even after driving long periods. I had it tested by Walmart and Autozone multiple times, the result always came back good. Turns out, the main wire from the altenator to the battery had a ton of corrosion. I sanded/wire brushed that off and my voltage returned to the proper 12.5+ volts.

Not sure if that helps, but it puzzled me for months and I figured I should share the knowledge... Otherwise, best of luck with finding a solution!

[SVX_MY_BABY]

I had the mechanic check the wiring and connections on the alternator and battery when I had some exhaust work done. He says all looks fine.

Car has performed normally until two days ago when it stuttered for a brief second then half an hour later it completely died on me. I pulled over at which point all the dash lights were on as if I had just put the key into the ignition. I started the car and it's been working fine.

I hate these types of intermittent problems.

The weather is now hovering near the freezing point. As soon as I get a warm day I'm going to go through all the connections myself. Hopefully I'll find something.

[Blacky]

Sounds like it could be the MAF sensor. There's lots of info on site and I think a "How to" for resoldering the connections inside. The MAF was repaired on my '97 by the previous owner and I did one on the Ebony '92. Same symptoms.

[Noriyasu]

Maybe there is a problem with the ignition switch?

[SVX_MY_BABY]

Thanks for the tips.

I checked the CEL codes. 37, 32 and 23.

37 and 32 are the O2 sensors. 23 is the MAF sensor

I've always had one O2 which is slow to activate. I'm surprised to see the second as I just replaced it when I replaced the manifold.

I cleaned the MAF and connectors with MAF cleaner, cleaned out the air box and replaced the air filter.

I did the procedure to clear the codes.

Two codes remain. One O2 sensor and the MAF sensor.. The other O2 code is gone. I did the clear code procedure three times but no change.

This surprises me as I thought all codes would clear until the car was driven far enough to set a new one.

Am I missing something?

[Noriyasu]

A fake DTC error may occur due to the battery voltage being lost.

For example, if you have recently replaced the MAF/O2 sensor with a new one and the error still occurs, suspect this. If the sensor is indeed abnormal, the DTC code will remain in the ECU even if the instrument cluster does not become abnormal.

[Blacky]

If you had another MAF, you could could swap them and see if the problem is still there. Try driving it and see what happens. If it has the common MAF sensor issue, only resoldering it will solve the problem.

Different codes are triggered by different events. The number of starts/stops, driving cycles etc.

[SVX_MY_BABY]

I was thinking of disconnecting the battery for a few minutes. I am assuming that doing that would clear the codes.