240SX Power Loss When Cold

[ziggy682]

Well, I seem to have a problem with my 1991 240SX. Whenever the engine is still warming up, I experience huge power loss for about the first 1/2 second whenever I give it gas. Every time I shift and get back on the gas, I lose power at first, and then it comes back 1/2 second later. This only happens when the engine is still warming up, and goes away once it is up to temp. I never give the car much gas when it is cold, so this usually happens at about 1/4 throttle.

The power loss is very severe, and it immediately comes back after about 1/2 a second. I think something is making the computer cut back the timing or fuel. I checked the computer and it isn't throwing any codes, and the oxygen sensor checked out just fine when I ran the self diagnostic.

Any ideas or help would be greatly appreciated.

[QuinGarcia]

sounds like it's leaning out on you when its cold. Is the spark strong and ign. systen in good shape? Are you getting a hiccup, or just a smooth loss of power? In other words does the engine just jolt or does it just not accelerate for a second?

[ziggy682]

Well, I put new spark plugs in it, but I haven't checked the ignition system to see if it's firing stong. The engine just doesn't accelerate for a second. It always runs pretty smooth, it just doesn't seem to have any power for a second.

[TrunkMonkey]

how long do you run your engine to allow it to warm up?

demetrius

[red240ne]

it might have something to do with a vacuum leak, just a thought.

[QuinGarcia]

make sure the timing is right and check the ignition first for strong spark. Each plug wire should have less than 30000 ohms of resistance from end to end. And pull off the rotor and cap and check for wear on the terminals. I agree that a vacuum leak could cause that hiccup because that would lean it out. Just have a gander at all the rubber around your engine. Vac leaks, leak in the intake ducting. Look closely.

[ziggy682]

Thanks for the suggestions. I'll check over that tomorrow.