blackmxma

iTrader: (3)

Having some serious issues with my '97. 127k miles, 5 speed.

Power at low end seems normal, but as soon as I get on the throttle at all, the car barely moves. It even sounds wrong, like deep and throaty. She had been throwing a knock sensor code, went ahead and replaced that. Now CEL is off and no codes, but no improvement in performance.

OBDII while driving shows ignition timing dropping like 10 degrees as soon as I hit the throttle. Plugs all look good and were replaced about 15k miles ago, cleaned the MAF sensor and throttle body. Anybody have any ideas of where to go next?

Thanks

JvG

The knock sensor code usually rides along with another code.
The cause of an issue with the car is almost always dye to the other code. A car with a bad knock sensor can be driven for years.

Does the fuel filter look like it's been there since the car was built? If so, replace it.

Another possibility is the maf sensor. The symptom of a bad one is normal performance at low rpm, and not much after 2500 rpm or so.

blackmxma

iTrader: (3)

The knock sensor was clearly cracked so needed replacing, but there weren't any other codes. I'll check the fuel filter. If MAF was bad wouldn't it trigger a CEL?

Thanks

JvG

Haven't had this issue myself.

From what I've read, not always, at least right away.

I'm an old guy. The cars I had when I was younger had carburetors. No codes at all. Then later a 1973 fuel injected volvo. Not even obd 1.

I rely on automotive theory and symptoms.
If a car acts a certain way, I can often ballpark guess what's wrong with it. I also been on this forum for a long time.
I know most of the issues, and what causes them.
I'm not always right yet my track record regarding guessing without codes is pretty good.

You have symptoms of fuel starvation.
The cause is possibly a fuel fliter, but it's also how a maf acts when it goes out.

Wait for other members to offer opinions.

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blackmxma

iTrader: (3)

I appreciate the help