mikmartn

Hi all,

98% of the time, my 1999 Maxima (Cali spec) runs great. But every once in a blue moon (say several weeks) the car almost stalls when I give it gas at stop lights. It keeps doing this until the next time I drive it and then everything is good again (often for several weeks).

I do have a P0158 code, but I believe that is a downstream O2 and shouldn't be a factor. I've replaced the MAF, spark plugs, PCV, fuel filter, air filter, cleaned the TB. Any other ideas?

Mike

JvG

This seems like a symptom of a vacuum leak.

I don't know what the cause is, or where it might be located. check your vacuum hoses.

one method is starting the car, then open the valve on an unlit propane torch.

place the head of the torch near any possible vacuum hose connections. if the engine speeds up, you have found your leak.

Caution: do this outdoors, and no smoking please.

mikmartn

Thanks JvG!

thegrindstone99

Did it work? I'm having the same problem with my '97. However, it's getting worse. Yesterday, I couldn't get it to go at all. It runs fine in neutral or park, but as soon as you put it in gear it starts trying to die again. Last week it died in the middle of one of the most dangerous and busy streets in my city. I had to neutral drop it (yes I know this is an awful thing to do and it tore me to shreds to do it, even though it was only from about 2700 rpm) just to get it going long enough to get out of the way.

mikmartn

I think your problem sounds different than mine. My problem only happens for an outing and then goes back to running well for weeks.

I haven't tried checking for vacuum leaks yet. I did adjust the throttle cable (removed a little slack) and cleaned the IAC. It's been running well for the past two and a half weeks, but that's how it goes. If it acts up again, I'll try the vacuum test.

M in KC

Check your guy's MAF connector. They have been know to be problematic, broken wire IIRC that will give intermittent symptoms you are describing. Other than that I would also be inclined to think vacuum leak.

Turbobink

iTrader: (2)

Agreed that the MAF may be the culprit.

Also, check your TPS resistances and adjust it as needed.