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Is this normal??? Guru's! by 4thfiero
Started on: 12-18-2013 10:12 PM
Replies: 15 (336 views)
Last post by: 2.5 on 12-20-2013 01:59 PM
4thfiero
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Report this Post12-18-2013 10:12 PM Click Here to See the Profile for 4thfieroClick Here to Email 4thfieroSend a Private Message to 4thfieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
Hey guys, still working out some gremlins in my rebuild, always super appreciative of your help! Three questions today...

1) After driving, you turn your key to shut the car off......does your volt gauge glow that red battery warning light for a second then shut off as you turn the key to off?? Is that normal? So, again...you turn your key to off...engine dies, and your volt gauge drops to 0 (bcc you just shut your car off) but the volt warning lights eluminated for litterally like half a second then shuts off...and i could sware it does it on and off...what is that?

2) My blower motor for my heat is squeeling like a mother whenever its turned on...the only way to stop it is to hit the "off" button on the climate control...has that happened to anyone before? would that be a bad blower motor? or electrical issue?...

3) When driving a standered Fiero...(standered tranny) lets say your going 60, then u see a red light where u will come to a complete stop....you shift into neutral and the tach guage drops to say 1100 rpm until the car coasts to a complete stop...then the tach drops to a normal idle...sometimes i notice my car do this, sometimes i notice that when i shift into neutral...the tach drops below 1000 rpm for a second and then idles around 1000 like it should when at a complete stop or parked...

does anyone know what this is? is that normal? is the car consistently supposed to idle at 1100 THEN 1000 or 900 after it stops completely?

Again thanks in advance everyone.
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RobertGT
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Report this Post12-18-2013 10:20 PM Click Here to See the Profile for RobertGTSend a Private Message to RobertGTEdit/Delete MessageReply w/QuoteDirect Link to This Post
1) Normal
2) Bad blower motor
3) Normal
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4thfiero
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Report this Post12-18-2013 10:33 PM Click Here to See the Profile for 4thfieroClick Here to Email 4thfieroSend a Private Message to 4thfieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
wow just like that eh? LOL, i appreciate the help, What is it...that makes the idle go like that in my last question??
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Raydar
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Report this Post12-18-2013 10:37 PM Click Here to See the Profile for RaydarClick Here to Email RaydarSend a Private Message to RaydarEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by 4thfiero:
... What is it...that makes the idle go like that in my last question??


It might be an emissions thing (using the engine to slow down does some ugly things to emission readings) or an anti-stall thing. (Letting the idle drop too quickly can cause a stall.)

In any event, most all manual tranny Fieros do it in some way.
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4thfiero
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Report this Post12-18-2013 10:41 PM Click Here to See the Profile for 4thfieroClick Here to Email 4thfieroSend a Private Message to 4thfieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
wow just like that eh? LOL, i appreciate the help, What is it...that makes the idle go like that in my last question??
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4thfiero
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Report this Post12-18-2013 10:47 PM Click Here to See the Profile for 4thfieroClick Here to Email 4thfieroSend a Private Message to 4thfieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
oops double post!

Interesting
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Blacktree
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Report this Post12-18-2013 11:49 PM Click Here to See the Profile for BlacktreeClick Here to visit Blacktree's HomePageClick Here to Email BlacktreeSend a Private Message to BlacktreeEdit/Delete MessageReply w/QuoteDirect Link to This Post
The ECM in the Fiero is pretty primitive, by modern standards. As a matter of fact, the speed with which it communicates with the engine sensors is so slow that it can literally take a second for the computer to realize what's going on. This is one of the reasons why people swap in newer ECMs.
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Report this Post12-18-2013 11:56 PM Click Here to See the Profile for theogreClick Here to visit theogre's HomePageSend a Private Message to theogreEdit/Delete MessageReply w/QuoteDirect Link to This Post
3. likely Anti stall is active.
Car moving then ECM knows that from VSS via Speedo line.

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4thfiero
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Report this Post12-19-2013 12:26 AM Click Here to See the Profile for 4thfieroClick Here to Email 4thfieroSend a Private Message to 4thfieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
That caught my attention...what ecm can be put in to work with an 86 2.8 v6???

 
quote
Originally posted by Blacktree:

The ECM in the Fiero is pretty primitive, by modern standards. As a matter of fact, the speed with which it communicates with the engine sensors is so slow that it can literally take a second for the computer to realize what's going on. This is one of the reasons why people swap in newer ECMs.


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Blacktree
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Report this Post12-19-2013 12:55 AM Click Here to See the Profile for BlacktreeClick Here to visit Blacktree's HomePageClick Here to Email BlacktreeSend a Private Message to BlacktreeEdit/Delete MessageReply w/QuoteDirect Link to This Post
As far as I know, there is no direct drop-in ECM. You'll have to make some wiring changes to swap in another ECM. The big question is whether or not it's worth the effort to do that, just to smooth out the idle a bit. Only you can answer that question.

In any case, a popular swap is the GM 1227730 ECM. There's a thread in the Construction Zone with all the details. Link --> http://www.fiero.nl/forum/Forum3/HTML/000088.html

And here's another ECM swap that seems to be gaining popularity --> http://www.fiero.nl/forum/Forum2/HTML/119333.html

That said, IIRC the computer doesn't go into "idle mode" until the vehicle speed is below a certain threshold AND the throttle is closed. This would explain why your engine doesn't idle down until after you come to a stop. And if you come to a stop pretty quickly, it'll take a second for the computer to respond, because it's slow.

Oh, and for what it's worth, the 7730 ECM (and probably the 7165 as well), has a similar feature. The ECM won't drop into "idle mode" unless the vehicle speed is below a certain threshold. However, that speed threshold is programmable. Plus, the idle speed is programmable. So you could tweak the programming to make the transition more seamless.
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4thfiero
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Report this Post12-19-2013 01:11 AM Click Here to See the Profile for 4thfieroClick Here to Email 4thfieroSend a Private Message to 4thfieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
Thanks guys!
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RobertGT
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Report this Post12-19-2013 01:12 AM Click Here to See the Profile for RobertGTSend a Private Message to RobertGTEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Raydar:
an anti-stall thing. (Letting the idle drop too quickly can cause a stall.)


That's exactly what it is, and the ECU does it by holding the IAC valve open slightly before stepping it down.

[This message has been edited by RobertGT (edited 12-19-2013).]

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Doober
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Report this Post12-19-2013 02:00 AM Click Here to See the Profile for DooberSend a Private Message to DooberEdit/Delete MessageReply w/QuoteDirect Link to This Post
I've noticed the anti-stall effect more when cold, but I've also seen it drop right to idle (no stumble, etc... just drops to idle rpm and stays there).

ECM: www.dynamicefi.com. I'm running one of Bob's ECMs in my '92 GMC with a TBI fed 383 with Vortec heads, I love it. Flashable, and much kore capable than the original GM stuff (uses part of the stock ECM, so it's possible no re-pinning is required). I plan to put one in mine to see how stock fueling compares to a wideband-tuned 2.8 eventually... they aren't the cheapest (definitely not the most expensive either).

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'87 GT 5-speed
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4thfiero
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Report this Post12-19-2013 03:14 PM Click Here to See the Profile for 4thfieroClick Here to Email 4thfieroSend a Private Message to 4thfieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
so i replaced my blower motor...only to find that the squeeling stopped, but my blower motor is not blowing hard! the first few settings blow like its on setting 1...and when i turn it to full blast? it doesnt do anything....no air blows...whats happening????
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Doober
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Report this Post12-20-2013 01:09 PM Click Here to See the Profile for DooberSend a Private Message to DooberEdit/Delete MessageReply w/QuoteDirect Link to This Post
Could be the resistors and high speed relay... does the motor have a good ground? I don't know enough about the wiring in a Fiero, but RockAuto shows the high speed relay looks like this (connector side):




I also came across this, worth a look, especially if you changed the blower & need to change the resistor:
http://www.fiero.nl/forum/Forum2/HTML/123929.html
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Report this Post12-20-2013 01:59 PM Click Here to See the Profile for 2.5Send a Private Message to 2.5Edit/Delete MessageReply w/QuoteDirect Link to This Post
The rolling idle is a common GM thing, I had a 90 Grand am that did it, as well as a 98 Saturn.
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