Rough idle

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shemdogg
Posts: 33
Joined: Wed Mar 15, 2017 1:20 pm

Rough idle

Post by shemdogg »

The car idles pretty rough, more so when warmed up. Feels liks its going to die/idle bounces around a few hundred rpms. Never does die. I dont trust the tach reading. I played w the timing, got a little more power but still runs ruff. All ignition components new minus coil. No codes

How to adjust the clutch? I have to shove the pedal to the floor for it to go in gear.

First gear is an absolute nightmare to find. Ive started backing up after the light turns green a few times. The shifter stays in the 3/4 position, 1/2 is over about 3/8" from there but the shifter doesnt wanna go into first most of the time. Ive started putting it in second then moving up to find first. Anybody else had this issue? is there an adjustment?

Turns out the AC still works in this thing lol. Belt is loose, found the connector on the compressor to plug in the wire. The fuse was missing from the fan system. So the rad fan comes on w the Ac but wont come on after my motors at 240 degrees. Burnt relay?

Thanks in advance

shem
ericjon262
Posts: 2819
Joined: Mon May 24, 2010 5:34 pm
Location: Aiken, SC

Re: Rough idle

Post by ericjon262 »

rodney dickman makes a master cylinder with an adjustable banjo, if your car has one, then it can be adjusted under the dash. I'm not sure there is any other adjustment available for the fiero clutch, I know my F23 has no provisions for adjustment. have you tried bleeding the clutch?

the shift linkage is not adjustable, but the shifters do wear out. Rodney makes a repair kit, I've installed one, it's not too hard, and does make a pretty good bit of difference.

http://rodneydickman.com/catalog/produc ... cts_id=171

he also has some nice replacement shift cables, with new ball studs pressed in, if your cables have plastic ends like some of them I've seen, they could be cracked leading to more play in the mechanism.

the fan issue is probably a bad temp switch. the cooling fan is driven off of it's own switch, not like the PCM on newer cars, the switches can fail,

here is the schematic from the service manual. you can see the a/c control switch is in parallel with the fan control switch, if your fan isn't working based on temperature, but it is when the A/C is on, the the switch and/or the wiring to it, are the culprit. of coarse, according to the schematic, the fan isn't supposed to come on until 235 F, so the system might be fine.
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Shaun41178(2)
Posts: 8358
Joined: Fri Nov 19, 2004 7:12 pm
Location: Ben Phelps is an alleged scammer

Re: Rough idle

Post by Shaun41178(2) »

What trans do you have? I am guessing 4 spd

I have a getrag 5 spd and I used a slave from a 5 spd Isuzu trans it allows clutch release about 1/3 to 1/2 way to floor. Faster shifts are a plus for what I do. Not sure if you can do the same for the 4 spd

You can try bleeding your clutch system as it might have air in it. Buy new slave seals if you keep getting air

I suggest you rebuild your shifter with new bushings and replace your shifter cables. If they are binding up, that will keep shifter from returning to nuetral position.

Your fan temp switch might be bad. You can short it out or maybe the wiring and see if the fan comes on. There is a test procedure that will tell you where the problem is at but not sure what it is off the top of my head.. You could always put in a lower temp fan switch

Start spending money man if you want things working like new
shemdogg
Posts: 33
Joined: Wed Mar 15, 2017 1:20 pm

Re: Rough idle

Post by shemdogg »

Thanks for the replies fellas! Yes its a 4spd and I think it does need new shift cable ends. I installed an electric temp gauge and used the sending unit thsts by the thermostat housing. It has a single green wire coming off of it. I found out theres 2 temp sensors, one by the tstat and one south of the coil. But diff threads have different opinions on which controls which. The fan works when I turn on the ac (ac actually works but belt is loose and squeals sometimes) but wont come on after the temp hits 240 and this motor heats up pretty quick. I will try bleeding the clutch I have a vacuum tool. Work picked up bigtime and ive no time for my new toy so sad. Ill post up more when ive had a chance to dig into it.

Shem
shemdogg
Posts: 33
Joined: Wed Mar 15, 2017 1:20 pm

Re: Rough idle

Post by shemdogg »

Was the site down for awhile I couldnt get the page to load for ages now. Anywho i got the ruff running fixed. I took the car in to get the fuel system cleaned, the timing set, and the belts changed. Car runs awesome now. Fanswitch from rodney didnt work so hes sending me another.

Thanks
again for the help

shem
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