1990 sentra motor stalling out

[RubenD]

My son has a 1990 Sentra that guess who's gonna get to work on it? It will crank, run smooth as silk for about 4 or 5minutes then just stalls out. It won't crank again until the motor is completely cold. I'm gonna work on it Tuesday so any ideas are welcome. I'm going to check the fuel pump. I'm also replacing a mile of vacuum hoses, but any other ideas are welcome

ThanksRuben

[nametakennow]

Do you smell gas as it runs? If an injector is stuck open, you'd be getting too rich so as to stall over time, and then you'd have to wait for the fuel to work its way out a bit before being able to crank it over again.

I wouldn't think that the fuel pump would consistently die after a few minutes, a dead pump is usually dead all the time. Same goes for a vac leak, you'd have trouble cranking and idling all the time if it was a vac leak.

If you rev it after those 4-5 minutes, right before it stalls, does it stay alive longer?

Welcome to NICO! Which motor is this, by the way? 1.6 or 2.0?

[RubenD]

thanks for the welcome. It don't smell gas. It does run for about 4 or 5 minute before it stalls. THan, if you crank it more it will ack like it wants to hit every few rounds but really don't even try to start again. Would a bad oxygen sensor cause this? It seems like when the motor just gets ward, but that be a coincedence. I am going to try and pour a little fas into the throttle body and see if it will start.

I'm prettysure it's the 1.6

[nametakennow]

Hmm..

Again, what about revving it? Will it stay alive longer if you put it in neutral and rev a bit?

I don't think a bad O2 would cause this, as the ECU would just run open loop and you'd be a little rich, but it'd run.

Cleaning the throttle body is a good idea for a car that old, as it may have been awhile since that's been done. If it's really dirty and impeding airflow, there may be a connection to your stall issue.

Does it sputter before dying or just cut out?

[RubenD]

No, it doesn't matter if you are revving or not...WHat ever the RPM, it's just like turning the key off. I'm working on it tomorrow morning for my son.. WHen cranking everyonce in a while it sounds like it may hit but that's about it. First thing I'm going to try is a small bit of gas down the throttlebody. It seems like it may be a connection or may even be a sensor or something. The last time it ran I disconnected the O2 sensor and that made no difference. I'm also going to look for any loose connection. At first I thought it might have been a timing gear or chain but when it ran as smoothly as it did for that short time I rulled that out.

When we bought the car. Didn't pay much. The guy had a timing chain andgears were replaced. along with a few other internal parts. Verified this through the mechanic that did the work. He's a well known and reputable mechanic here.

Well, while I'm in thre I'm going to replace all the vacuum hoses. I've replaced a few already that were completely broken...did that because the car was running terrable at one time. replacing those hoses fixed that problem.

Wish me luck. If all else fails . I'll drag it to a mechanic, but I think it's got to be something simple. Like I said... it purrs like a kitten when it runs..

ThanksRuben

[nametakennow]

It probably is something simple. I'll keep mulling it over and let you know if I think of anything.

When you figure it out, post it up here for future reference!

[RubenD]

You won't believe it. i was ready to spend my entire day looking for a problem that I was going to end up taking it to a Nissan deal for.Opened the hood( gotta be dramatic here ) took the air filter off..looked around and thought, lets look a the distributor cap. Pulled it off...BAM!!!!saw a scew fall out. Spun the plastic rotor with my finger. FOund the bolt and some locktite. Put that baby back in ...Vroommmm A very happy father and son. I did spend the next hour replacing all the vacuum hoses I could find. Most of the old ones were turning to coal.

Anyway, I knew it had to be something simple and THANK GOD!!...it was the first thing I checked. I spend more time repairing a key on his electric piano than I did on the car. This car looks like crap, but it runs like a sewing machine and gets almost 40 MPG.

I've gotta 240sx with 250,000 miles on it. Next week, it's tension rod replacement time and an alignment with new tires.

Thanks for the help..Have a great weekend.

Ruben

[nametakennow]

Ha! I love it when it works out like that. Good to hear.