my frist

[hurricanebilly]

okay i just got my frist lil gt and there are some things i need help with. this is a 1986 gt with 82,000 miles on it . the car runs great down the road at high way speeds, but when you are at idle it runs very rough . i am in the pocesss of learning how to use the forums so bare with me. also the fuel gauge and the speedometer dose not work.any help would be very useful.....

thank you.

 

[Goatman]

The first thing I would check would be the plugs , wires and the coil pack / distributor terminals for any corrosion then check the fuel filter and injector(s) you didn't say which engine you have so Im asuming a 2.8 v/6 in a GT..
also you did not say if you have a Check engine light on ..
the fuel guage could be a ground or float issue.. and I believe the speedos on them were still cable ..but I could be mistaken I would make a simple check to se if there is a cable for the speedo first .. there are a couple Fiero guys on here im sure will have some input ..

 

[Oreif]

For idle issues try a tune-up as goatman suggested. Also clean out the throttle body and check all vacuum lines. A small vacuum leak can cause some idle issues. On the Fiero 2.8L there are two areas to check often. The EGR tube that goes from the EGR to the upper intake plenum is notorious for cracking. You can get a new one from www.fierostore.com

The next area is all the vacuum lines under the plenum. GM used solid plastic lines and with age they tend to get brittle and split. You can replace them with all rubber vacuum hoses or small metal tubing. There are 5-6 lines to check.

The speedo is controlled by the Vehicle Speed Sensor (VSS) on the transaxle. It is not uncommon for the VSS gear to crack. The speedo is electrically controlled.

The fuel gauge could be the gauge or the sensor in the tank.

There is also a chance that the flex-print wiring in the dash could have cracked and the gauges are not getting power.

To help you check out the gauges, sensors, and wiring here is a link where you can download the GM factory service manual. http://www.fieronews.net/fusion/downloads.php?cat_id=13

This will tell you everything about the car as well as offer truobleshooting steps to repair it.

 

[hurricanebilly]

thanks

thanks guys ! it is a 2.8 and i have done the tune up and i think i will start to look at the v hoses today . fuel filter ?

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[Oreif]

thanks guys ! it is a 2.8 and i have done the tune up and i think i will start to look at the v hoses today . fuel filter ?

Fuel filter is located on the passenger side on the bottom of the firewall.
If it's dirty it can cause a rough idle due to slightly lower fuel pressure.