outrider

I posted a while ago with a strange engine problem. My car would only start if you rolled the engine over and then let the key off. it would sputter for a minute then come to life. It also is idling VERY high, like 2 grand. the idle screw is all the way down. I have it now so you can almost start it normal. it takes a few trys, but then it will start. I ended up dragging the timing so far back that my timing light doesnt even read on any of the marks now. it obviously is lacking serious power because of the incredibly high retarded timing. i can tell there is some get up and go in there, but its still not even close to my 86 300zx, so i know there is still a problem. The guy i bought the car from said it was a sensor, but i cant figure out which sensor would cause such a problem. maybe knock sensor i guess. the car also backfires a lot when sitting at an idle, and will very occaisonly stall. so far all i have done is replace the plugs and wires, and messed with the timing. any help of what tests to do next would be appreciated.

-Nick

SecretAsianMan

Nick--

Let's get started with some personal history, cough for me :-)

1. When you removed the old plugs, how did they look?
2. What brand/type did you remove?
3. What brand/type plugs did you re-install?
4. Why did you replace the wires?
5. Did you replace the wires with Nissan factory wires or some other brand?
6. Why did you change the timing?

--SAM

outrider

Ok, here goes.

Let's get started with some personal history, cough for me :-)

1. When you removed the old plugs, how did they look?
They have been running rich, a lot of excess carbon

2. What brand/type did you remove?
Nasty K-Mart Autolite

3. What brand/type plugs did you re-install?
Nothing other then Nippon Denso

4. Why did you replace the wires?
I always replace wire when I change plugs. Usually cap and rotor as well. No sense in putting freash plugs in when the juice has to get through nasty old wires to get to them.

5. Did you replace the wires with Nissan factory wires or some other brand?
Nissan stock

6. Why did you change the timing?
Origanlly I did it just cuz, and when it made the car start running, I retarded the timing more to try and keep the car running so i might pull some codes from the ECU. It's not getting any codes though, says its running fine. Now I have been drivingfor a few days to see if it would clear itself up. say just gunk in the engine from sitting for several years. Its not working though.

Just for a little background info on myself. I have fairly reasonable mechanical knowledge. Ive check most of the obvious stuff, but i wanted some opinions on where to go first, before i started testing every sensor in the car. I have swapped a turbo MR2 engine into a celica. Working on putting a twin turbo Z engine in my 86 NA 300ZX. and probably will end up dropping a the engine out of my smashed broke *** 84 turbo Z into the maxima someday. As much as i keep telling myself no mods, this is a winter car, family sedan, the demons in my head keep saying its not fast enough.

A little background on my car that may be useful, im sorry for not posting it before. Its a 89 SE 5spd. got it for 500 bucks, hehehe. not a spot of rust on it, a few dings, nothing major. 35,000 miles, everything works, even the AC. so i was excited to get in running. the guy i got it from was excited to be getting rid of his sons lawn ornament. he pretty much gave it to me because he thought it would never run, and only good for parts. interior is imaculant. no tears, no burns or anything. My girlfriend vacumed and armoralled all the leather and vinyl, and it looks great. anyways, sorry for the long post, but there is the background info, now if only i could unlock the full furry of the heart under the hood, maybe ill be content until spring at least, when the snow goes away.

-Nick

SecretAsianMan

Nick--

I believe your car has a timing belt rather than a timing chain. If so, and even though it only has 35K miles, it would consider it a high risk item because of its age. Perhaps it has slipped a tooth and is the cause of the timing problem?

You may also want to take a closer look at the distributor's advance mechanism and make sure that isn't stuck and in need of lubrication. I'd also inspect the vacuum lines.

A faulty oxygen sensor or bad sensor connection can cause the engine to run rich.

Other general comments regarding an old, low mileage car that has been sitting...

Lot's of electrical connections may be oxidized/corroded.

Gasoline was probably left sitting in the system without the benefit of a fuel stabilizer. You may want to disconnect the fuel line and pump some gasoline into a jar to see how clean it looks. I'd consider the fuel system to be another suspect area.

The corrosion inhibitors in the anti-freeze are probably gone.

If the tires are original, anticipate a blow-out when you go for a drive.

Good luck and let us know what you find.

--SAM

outrider

Any idea on what the oxygen sensor should do, as far as voltage output at normal opperating temp. I dont really have time to go get a book right now, so if someone could spout of the numbers, that would be helpful.

-Nick

SecretAsianMan

http://www.mr2.com/TEXT/O2_Sensor.html

outrider

ok, here is the latest. the other day i was driving home when about a mile form my house, the engine just quit running and would not start. i walked home, took my girlfriend and her car to the site of the car. i had her push me with her car and popped the clutch. the car started running again and i made it about a half of a mile when it just cut out again. so i coasted home, then tried starting the car again... nothing. so i put a new crank angle sensor in it yesterday, and after sitting all night with the battery charger on it (i ran it dead trying to start it the night before) i tried starting it. after a while of playing with the gas pedal i got it to start. I adjusted the timing via timing light, and got the car running perfectly. before i took off with it, i turned it off, and tried to start it again. nothing... dead. so i am pretty sure now it is ignition, because it is getting plenty of gas. but the spark is really weak if any at times, so i start testing things. I come to this power transistor thing, which looks pretty expensive, and it fails every continuity test. with everything i have said, can anyone conclude that the power transitor would provide these sort of symptoms? what the heck does it do anyways? and where is the cheapest place to get one? thank you all again

-Nick

outrider

i replaced the power transistor, the coil tests fine, the crank angle is new. It runs better, but while driveing along, it will randomly cut out for a second or 2 and then start running again. doesnt happen very often, and never when racing the engine at higher R's. Any ideas?

-Nick

SecretAsianMan

outrider--

Sounds like you may have an intermittent electrical short or open, perhaps a faulty ground link?

http://www.misterfixit.com/badgrnd.htm

http://yarchive.net/car/intermittent_ground.html

http://www.babcox.com/editorial/ic/ic110127.htm

--SAM