86 Lebaron RPM "surging" problem

Go here if you can't find the answers to your car's problems

Moderator: 89ARIES

86 Lebaron RPM "surging" problem

Postby Bobthecat » Sat Jul 25, 2015 4:59 pm

For an 86 LeBaron Conv. with Turbo: 99% original. Had the car since 1990 and this is the first time it started doing this. The engine "surges" in other words the RPM goes up and down without touching the accelerator. This is damaging the trans when it slams into gear at (estimate 1,500-2,000 rpm), or I wait until it just goes back to normal in idle, sometimes 3-5 minutes of just high RPM's. Have to turn it off in gear to stop dieseling after turned off with key. Seems to have a mind of it's own. I know I'm not the first one with this goofy problem. But no one but me can drive it because it isn't safe in traffic. What part(s) need to be replaced? Thank you in advance for your support.
Bobthecat
 
Posts: 2
Joined: Wed Jul 22, 2009 1:55 pm
Car Information: 82-86 LEBARONS

Re: 86 Lebaron RPM "surging" problem

Postby Kwagon2 » Sat Jul 25, 2015 10:21 pm

There could be any number of things going on here first thing see if any fault codes come up. With the engine off you cycle the ignition switch three times with it left "on" on the last cycle. Count the flashes that appear on the "power loss" light the light will blink for each digit with a pause between each set of codes. See what shows up
Check for vacuum leaks around the intake manifold also check the wiring and general operation of the TPS (Throttle position sensor) What you're looking for is anything that could affect the info going to the computer that would make it increase the fuel pulse width thereby increasing engine speed. Timing could also be affected, if timing suddenly advances via the computer engine speed will increase. For starters disconnect and plug the vacuum line to the computer advance pot and see if it calms down any. Check the vacuum line to the MAP sensor on an '86 its inside the car on the logic module. Post what you get for fault codes as a start, but look for obvious stuff first.
Kwagon2
Car Fan
 
Posts: 140
Joined: Tue Jun 09, 2015 2:46 pm
Car Information: '82 Aries Wagon,'85 Reliant SE,'82 Reliant Wagon

Re: 86 Lebaron RPM "surging" problem

Postby Bobthecat » Sun Jul 26, 2015 5:52 pm

Thank you kwagon2. That was a great bit of information. I'll try it and hopefully we can find the problem.
Thank you again!
Bobthecat
 
Posts: 2
Joined: Wed Jul 22, 2009 1:55 pm
Car Information: 82-86 LEBARONS


Return to Technical Support

Who is online

Users browsing this forum: No registered users and 8 guests

cron