Hard Start with High Idle

Asked by May 20, 2011 at 10:03 PM about the 1984 Pontiac Fiero SE or Indy

Question type: Maintenance & Repair

1984 Fiero SE Automatic.
This one is driving me crazy!  I has spend about $1,000 in parts and repair time at a local shop.  Car always had a bit of a high idle (about 2,000 RPM), but I could live with it.  About a week ago, the car began having problems starting.  It turns over fine (battery new) for about 30 seconds, then finally fires up and idles (although 2,000 RPM), and runs just fine.  Then as the week went on, the car took longer and longer to start.  Now it takes a good couple of minutes to get started. It has been at the shop for 2 days, and they can't figure it out either.  Fuel pressure test is 42 psi.  I have tested and or checked: MAP, MAT, IAC, engine temp sensor, cap, rotor, spark plugs, plug wires, EGR/EGR tube, Ignition module, and checked for vacuum leaks.  I have replaced (for the heck of it): MAP, IAC, engine temp. sensor, cap, rotor, ignition control module, and plug wires.  I am getting an IAC error from the ECM, but assume it is a false error because the computer can't bring the idle down, so it thinks the the IAC is bad.  Even ignoring the high idle, it still has a major problem starting.

I verified that each plug is getting spark by connecting the timing light on each wire.
I then connect the timing light on the output of the induction coil, and cranked the engine.
I get consistent flashing (good sparks) from the timing light.  After a minute of cranking, I smell plenty of gas fumes from the exhaust tips.

So, I get gas to the engine, good sparks from the ignition coil, but still takes a long time to start, and then idles a bit high (2,000 RPM).
Any ideas?  Something I haven't thought of?

3 Answers


Sounds like you might have some intake leak, or some other gasket thats not sealing correctly. Get some carb cleaner and spray it around the intake or anyother place that you might think air might be getting in.

1 out of 1 people think this is helpful.

have you done anything with the tps? throttle position sensor? i had a high idle problem with my 84 2.5. changed the tps and it went away

2 out of 2 people think this is helpful.

Had the same issue. Replaced tps, iav, map sensor....nothing helped. Looked for air leaks....none. egr ok. Moved the bundle of wires along the left side of the engine. And the rpm suddenly dropped to normal. Check for shorts as well. With all that my tps really needed to be replaced so not all wasted time. Good luck and long live the fiero.

1 out of 1 people think this is helpful.

Your Answer

Add photo

Related Questions

  • Hard start and a bit lean 2 answers

    Just got an 88 Fiero. Most of the time it runs great. BUT! Sometimes it will start, run for a second or 2 then quit. Does that several times running longer each time the eventually keeps running. At f...

    1988 Pontiac Fiero Base


    Maintenance & Repair

  • High Idle 2 answers

    My fiero developed a high idle problem, idle near 3k, I have checked for vacumn leaks, throddle body is ok and have replaced the throddle position sensor, any help would be appreciated....thanks

    1985 Pontiac Fiero GT


    Maintenance & Repair

  • Start/Idle 4 answers

    88 Fiero 4cyl. Sometimes it acts like maybe it is flooded. Wont start. Wait about an hour and it starts but idle bounces between 500-1500 rpm for a minute then smooths out. Has a new IAC and fuel ...

    1988 Pontiac Fiero Base


    Maintenance & Repair

  • will not stay running 3 answers

    car starts, run's 3 or 4 seconds then quits and it restarts runs 3 or 4 seconds

    1986 Pontiac Fiero GT


    Maintenance & Repair

  • Idles too high 1 answer

    Car idles at 55 mph without my foot on accelerator and idles high in park as well

    Pontiac Grand Am


    Maintenance & Repair


Looking for a Used Fiero in your area?

CarGurus has 66 nationwide Fiero listings and the tools to find you a great deal.


Search Pontiac Fiero Questions

Pontiac Fiero Experts

#1 Steve Neyens
Steve Neyens
Reputation 220
#1 Andrew Welsh
Andrew Welsh
Reputation 220
Reputation 210
View All

Related Models For Sale

Used Pontiac Firebird
7 Great Deals out of 789 listings starting at $1,800
Used Chevrolet Corvette
112 Great Deals out of 20,672 listings starting at $3,499
Used Chevrolet Camaro
132 Great Deals out of 35,283 listings starting at $1,995
Used Ford Mustang
316 Great Deals out of 45,523 listings starting at $2,000
Used Toyota MR2
23 listings
Used Nissan 300ZX
128 listings starting at $3,995
Used Honda Civic
488 Great Deals out of 80,457 listings starting at $558
Used Porsche 911
95 Great Deals out of 4,420 listings starting at $11,900
Used Dodge Charger
248 Great Deals out of 27,238 listings starting at $1,997

Used Cars For Sale