Pennock's Fiero Forum
  Technical Discussion & Questions
  3.1 idle question

Post New Topic  Post A Reply
Email This Page to Someone! | Printable Version


next newest topic | next oldest topic
3.1 idle question by Luperman
Started on: 12-30-2021 05:15 PM
Replies: 9 (107 views)
Last post by: fierofool on 01-09-2022 03:10 PM
Luperman
Member
Posts: 182
From: maurertown, VA
Registered: Dec 1999


Feedback score: (2)
Leave feedback

Rate this member

Report this Post12-30-2021 05:15 PM Click Here to See the Profile for LupermanClick Here to Email LupermanSend a Private Message to LupermanEdit/Delete MessageReply w/QuoteDirect Link to This Post
for anyone who has done the 3.1 conversion, does the idle run a little rough but smooths out once you give it some gas not sure if it would do this with all the parts from the previous 2.8 engine installed on it, this was a new crate motor for a chevy lumina, I have pulled each plug wire one at a time and the idle does not change, this was installed on my 86 GT, any suggestions would be helpful
TIA Donald
IP: Logged
PFF
System Bot
Patrick
Member
Posts: 32148
From: Vancouver, British Columbia, Canada
Registered: Apr 99


Feedback score: (1)
Leave feedback





Total ratings: 450
Rate this member

Report this Post12-30-2021 05:49 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Luperman:

I have pulled each plug wire one at a time and the idle does not change


That's odd.

I hope when you're doing this that you're grounding the plug wire (to prevent damage to the coil).

IP: Logged
Luperman
Member
Posts: 182
From: maurertown, VA
Registered: Dec 1999


Feedback score: (2)
Leave feedback

Rate this member

Report this Post12-30-2021 08:10 PM Click Here to See the Profile for LupermanClick Here to Email LupermanSend a Private Message to LupermanEdit/Delete MessageReply w/QuoteDirect Link to This Post
yeah I did ground each time,
IP: Logged
claude dalpe
Member
Posts: 114
From: montreal,quebec,canada
Registered: Feb 2009


Feedback score: (1)
Leave feedback

Rate this member

Report this Post12-31-2021 10:58 AM Click Here to See the Profile for claude dalpeClick Here to Email claude dalpeSend a Private Message to claude dalpeEdit/Delete MessageReply w/QuoteDirect Link to This Post
Luperman

You don't detect any change in RPM because your IAC compensates for the loss of RPM when you unplug each plug wire, if you really want to see a difference unplug the IAC.
You say it's a new crate engine, let it run a bit, you have to break it in and the ECM is to learned the new engine. Go do some KM.
IP: Logged
Luperman
Member
Posts: 182
From: maurertown, VA
Registered: Dec 1999


Feedback score: (2)
Leave feedback

Rate this member

Report this Post12-31-2021 07:25 PM Click Here to See the Profile for LupermanClick Here to Email LupermanSend a Private Message to LupermanEdit/Delete MessageReply w/QuoteDirect Link to This Post
I took it for a small drive today it has great power response trying also to get the TV cable set right I had to let off the gas each time for it to shift to the next gear, I think also the tach might be off some roller at 60 MPH and the tach is at 3200 rpm sucks I only have one day each week to get to work on it now so I got to take my time with working out the bugs, just happy it runs after working on this project for the last year and a half.
IP: Logged
Luperman
Member
Posts: 182
From: maurertown, VA
Registered: Dec 1999


Feedback score: (2)
Leave feedback

Rate this member

Report this Post01-09-2022 06:11 AM Click Here to See the Profile for LupermanClick Here to Email LupermanSend a Private Message to LupermanEdit/Delete MessageReply w/QuoteDirect Link to This Post
Does anyone know if the 2.8 fly wheel flex plate could cause this roughness at idle since it is installed on the 3.1 engine ?
IP: Logged
fierofool
Member
Posts: 12316
From: Auburn, Georgia USA
Registered: Jan 2002


Feedback score:    (13)
Leave feedback





Total ratings: 153
Rate this member

Report this Post01-09-2022 08:32 AM Click Here to See the Profile for fierofoolClick Here to visit fierofool's HomePageClick Here to Email fierofoolSend a Private Message to fierofoolEdit/Delete MessageReply w/QuoteDirect Link to This Post
If you used a pre-88 flex plate, you can have issues. The 3.1 engine is internally balanced and needs a neutral balanced flexplate or flywheel. You might find some roughness at idle. In the case of a 3.1 with a manual transmission externally balanced flywheel, it can do damage to the crankshaft bearings and seal.
IP: Logged
Luperman
Member
Posts: 182
From: maurertown, VA
Registered: Dec 1999


Feedback score: (2)
Leave feedback

Rate this member

Report this Post01-09-2022 09:28 AM Click Here to See the Profile for LupermanClick Here to Email LupermanSend a Private Message to LupermanEdit/Delete MessageReply w/QuoteDirect Link to This Post
well that may be my roughness issue due to me using the original 86 flex plate, dang just when I got it all together, I didnt even think to look into that , thanks for the info fiero fool
IP: Logged
Luperman
Member
Posts: 182
From: maurertown, VA
Registered: Dec 1999


Feedback score: (2)
Leave feedback

Rate this member

Report this Post01-09-2022 09:32 AM Click Here to See the Profile for LupermanClick Here to Email LupermanSend a Private Message to LupermanEdit/Delete MessageReply w/QuoteDirect Link to This Post

Luperman

182 posts
Member since Dec 1999
I checked rock auto and found these listed but it said without weights?
https://www.rockauto.com/en...matic,flexplate,8608

will one of these still work for my 3.1 issue?
IP: Logged
fierofool
Member
Posts: 12316
From: Auburn, Georgia USA
Registered: Jan 2002


Feedback score:    (13)
Leave feedback





Total ratings: 153
Rate this member

Report this Post01-09-2022 03:10 PM Click Here to See the Profile for fierofoolClick Here to visit fierofool's HomePageClick Here to Email fierofoolSend a Private Message to fierofoolEdit/Delete MessageReply w/QuoteDirect Link to This Post
Without weights is the 88 neutrally balanced flexplate. Anything above the 88 will be neutrally balanced. I have a Lumina APV 3.1 in one of my cars and I'm using a flywheel from a 91 Beretta.

[This message has been edited by fierofool (edited 01-09-2022).]

IP: Logged

next newest topic | next oldest topic

All times are ET (US)

Post New Topic  Post A Reply
Hop to:

Contact Us | Back To Main Page

Advertizing on PFF | Fiero Parts Vendors
PFF Merchandise | Fiero Gallery | Ogre's Cave
Real-Time Chat | Fiero Related Auctions on eBay



Copyright (c) 1999, C. Pennock