84 Duke runs rough on start up? (Page 1/1)
johnt671 JUL 27, 01:24 PM
I had to do some electrical work on my 84. I got done with it and now when I first start it, instead of running at 1800 RPMS, it idles low and spits and sputters. If I give it some gas it smooths out and runs like it's old self. It is my guess that it's rich when it first starts, but I've got no idea how or what to begin with.
Sanhino JUL 27, 01:37 PM

quote
Originally posted by johnt671:

I had to do some electrical work on my 84. I got done with it and now when I first start it, instead of running at 1800 RPMS, it idles low and spits and sputters. If I give it some gas it smooths out and runs like it's old self. It is my guess that it's rich when it first starts, but I've got no idea how or what to begin with.



What electrical work did you work on? It could probably be a range of things: TPS, temp sensor, etc.
johnt671 JUL 27, 02:48 PM
It started out with everything on fuse # 11 cutting out but the fuse didn't blow. Based on some suggestions on here I replaced the original cigar lighter, but the circuit still intermittently failed.

I went to the red wire coming off the positive cable and wiggled it. Some sparks flew and the circuit started working. I disconnected the cable and pulled the tape off and found a few splices so I cut them all off and used one splice instead. When I put it back together the poor start up started. Also the #11 fuse blew, so I removed the new lighter and the fuse held up. now I'm left with the idle problem. I was on the pass. side doing this work.

Plus the pass side headlight motor won't pop up and the left one is slower. I'm not too worried about that for now. Thanks.

[This message has been edited by johnt671 (edited 07-27-2020).]

Gall757 JUL 27, 04:30 PM
poor idle may be due to clearing the ECM. It needs a drive around a few blocks to re-set a few values.
johnt671 JUL 27, 05:42 PM
I took for about a ten mile ride after I connected the battery. All the times I reset the computer the Idle was way high and the check engine light came on. Then the idle would settle down to normal. Now it's low on start up but after giving it some gas it drives and idles normally.
johnt671 NOV 14, 03:23 PM
I tried any thing I could think of to fix this. Swapped a different throttle body, Two used and one new ISC countless resets of the computer and ISC. and a bunch of drives. It's not easy to drive with an idle between 3 and 4 thousand RPM's. I gave up and put it in the shop, who said he couldn't figure it out. Said he didn't have anything he could use to test an older car. I took the car back Friday. I sit here thinking what the heck it could be and the only thing I didn't think of was the computer, but it was a rebuilt unit from The Fiero Store. I swapped The Fiero Store unit I got last June, for a spare and the car is now back to it's old self.