88 nissan - last ditch effort

[resonant]

Ok. I have the mechanical abilities of a tryllobite, so bear with me while I try and explain this.
My 88 Sentra seems to be on its last leg. When I start it up first thing in the morning, it runs ok for a few minutes. Then the idle begins to fluctuate...it will rev up really high, then drop down until it almost dies. It does this between four to six times, then will even out again. After 10 minutes or so of this, it finally dies completely. I can re-start it, and it will immediately go into it's erratic idle and die within moments.

That covers symptom #1. Now for #2...it won't stay alive when I come to a stop. Actually, I don't even have to stop. If I take my foot off of the gas and engage the clutch, it will die within moments. However, I can easily re-start it by working the clutch, and as long as I keep giving it gas, it's fine. Also, it seems to hitch a bit more than usual. After a week or so of these problems, it became nearly un-drivable. Constant hitching, stopping dead, ect. Changed plugs, filters. Ran great for a few days. Now the problems are coming back. HELP!!!

p.s - Sorry for being long winded. just trying to give details.

[In2Deep]

which motor is in your sentra? is it carburated? it may not be dialed in. also, check the timing/distributor for cracks, etc. and make sure the timing is right.

[lorenzob]

are the spark plugs gapped right i had the same problem with mine andi was gapping them wrong. i found this out after the head gaskets were changed

[blackmaxima88se]

have you checked all the vacuum lines? this is a common culprit. if there's a vacuum leak, you'll hear a hissing sound under the hood.


if that didn't fix it, take out your air cleaner and check the carbon buildup. excessive carbon buildup will also cause this. look at the throttle plate while turning the throttle body with your hand. anythig black is carbon. get a can of STP throttle body/air intake cleaner (DO NOT use carb cleaner because this will destroy the teflon coating) and spray it into the throttle body while opening and closing the throttle. scrub off any carbon with your finger. chances are it will be thick. this will probably make at least a little bit of an improvement. another recommendation is to buy a can of Seafoam Motor Treatment (that stuff works). Start the engine, disconnect the big vacuum line at your power brake booster, and slowly pour the Seafoam into that vacuum line. pour about 1/3 of the can in there, shut the engine off, reconnect that vacuum line, and let the engine sit for about 5 minutes. the start it back up and give it some gas. you'll see a lot of white smoke from the exhaust as it circulates that cleaner through the intake and into the cylinders. you may need to put more Seafoam in there.

even if that didn't completely fix it, it's a good preventative maintenance item. carbon buildup is a major cause of a seriously unstable idle. if it's still doing that, you can do a self-diagnosis of the car's computer. it's not hard, and it'll tell you what problems have developed with the engine. let me know if that's the way you wanna go. I can give you directions. anybody can do it.

Dan