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modifying for mass air flow meter? by donuteater306
Started on: 04-18-2015 12:58 PM
Replies: 13 (161 views)
Last post by: theogre on 04-20-2015 03:06 PM
donuteater306
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Report this Post04-18-2015 12:58 PM Click Here to See the Profile for donuteater306Click Here to Email donuteater306Send a Private Message to donuteater306Edit/Delete MessageReply w/QuoteDirect Link to This Post
I tried "search" and didn't find anything, which probably means it's not worth the time or is possible. But here's my question.

Has anyone modified their stock 2.8 to run off of a MAF like the 2.8 in say, an 87 Cutlass Ciera? Reason I ask, the idle in my Fiero (and other Fieros with 2.8's that i've driven) intermittantly hunts when at idle. Occasionally it will stabilize, but most of the time it sits there hunting. I've checked for vacuum leaks, cleaned the IAC and passages, and replaced all of the usual maintenance items. It just seems to be a normal operation. Our old Ciera doesn't do this. I was told that it's because the difference between management systems. What are your thoughts?
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Gall757
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Report this Post04-18-2015 02:09 PM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
If it were a difference in software or data management, my Fiero would have a hunting idle too, and it does not. From what I can read, most Fieros don't have a hunting idle.
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donuteater306
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Report this Post04-18-2015 04:40 PM Click Here to See the Profile for donuteater306Click Here to Email donuteater306Send a Private Message to donuteater306Edit/Delete MessageReply w/QuoteDirect Link to This Post
Well that's a bummer. I assumed that I had checked every cause: timing, tune-up/ignition components, vac leaks, egr. What's left? The two 87 GT's that I have, one a 5spd, the other an automatic both do this. The one with an auto trans has less than 100k miles on it. Both have an unsettled idle.
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Gall757
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Report this Post04-18-2015 06:40 PM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
I wonder if there is something special about the '87 chip. Mine is a 88.
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donuteater306
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Report this Post04-18-2015 11:33 PM Click Here to See the Profile for donuteater306Click Here to Email donuteater306Send a Private Message to donuteater306Edit/Delete MessageReply w/QuoteDirect Link to This Post
I doubt it. There's probably something wrong.
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tom10122
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Report this Post04-18-2015 11:55 PM Click Here to See the Profile for tom10122Click Here to Email tom10122Send a Private Message to tom10122Edit/Delete MessageReply w/QuoteDirect Link to This Post
My 88 idle swings +-100rpms if the ac is on, +-50 off. I do have a vaccum leak at my solenoid though (rebuilt once before improperly)
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donuteater306
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Report this Post04-19-2015 12:04 AM Click Here to See the Profile for donuteater306Click Here to Email donuteater306Send a Private Message to donuteater306Edit/Delete MessageReply w/QuoteDirect Link to This Post
Mine is acting similarly. What solenoid have you rebuilt? The egr?
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Gall757
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Report this Post04-20-2015 01:19 PM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
Are you using stock injectors? There have been cases of replacement injectors causing a bad idle.
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dobey
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Report this Post04-20-2015 01:30 PM Click Here to See the Profile for dobeySend a Private Message to dobeyEdit/Delete MessageReply w/QuoteDirect Link to This Post
The only time I've ever had a "hunting idle" problem on a 2.8 Fiero, it was the A/C compressor cycling due to being locked up.
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theogre
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Report this Post04-20-2015 01:32 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
power and grounds problems in engine or other parts of car can cause idle hurting.

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donuteater306
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Report this Post04-20-2015 02:15 PM Click Here to See the Profile for donuteater306Click Here to Email donuteater306Send a Private Message to donuteater306Edit/Delete MessageReply w/QuoteDirect Link to This Post
All stock injectors. I'm going to check grounds and double check for vac leaks. I dribbled chemtool over vac lines and joints a few weeks back. Didn't get any rpm changes. My engine compartment is really clean and all of the lines are routed as they were from the factory. Nothing added or Mickey Mouse'd. It's just that when I get off of the freeway and step on the clutch, the rpm's drop then hunt around for a while when in neutral when waiting at the stop light. Less obvious with the a/c on. Sometimes at idle, the rpm will drop for a second, stumble around then pick back up again. Then hunt, then stabilize. I don't understand why, the car is only 28 years old
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Riddick85
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Report this Post04-20-2015 02:24 PM Click Here to See the Profile for Riddick85Send a Private Message to Riddick85Edit/Delete MessageReply w/QuoteDirect Link to This Post
I would say the same as ogre. If you haven't checked/changed the grounds in awile, add some. Can't hurt and is a pretty common problem. Battery to engine and battery to body
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tom10122
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Report this Post04-20-2015 02:49 PM Click Here to See the Profile for tom10122Click Here to Email tom10122Send a Private Message to tom10122Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by donuteater306:

Mine is acting similarly. What solenoid have you rebuilt? The egr?


Yes the egr solenoid , the coil was pretty dirty and was soldered up once before. The seal around the coil was damaged pretty bad too which is where I believe it to be leaking, haven't had enough downtime to try some silicone on it.
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theogre
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Report this Post04-20-2015 03:06 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
 
quote
Originally posted by Riddick85:
I would say the same as ogre. If you haven't checked/changed the grounds in awile, add some. Can't hurt and is a pretty common problem. Battery to engine and battery to body

Sadly no... Is a popular myth but Adding grounds can make more problems.

Fix/replace Any loose/weak/"bad" grounds and connectors because they can create "ground looping" and other problems.

ECM has several grounds bolted to engine and body. ECM really hates ground noise often cause by ground loops.
Engine to body have at least two. You can replace the braided ground w/ heavy braid w/ better spot to anchor on car side.
More see my Cave, Wire Service
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