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Topic: 82 CFI Fast Idle Revisited

in Forum: C3 Fuel, Emission Control, and Exhaust Systems


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82 CFI Fast Idle Revisited (19/29)
 11/12/10 9:45pm
kwoody
Former Member

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Tucson, AZ - USA

Vette(s):
1982 Black/Tan Leather Build Code C09E Bronze TTop CrossFire Fuel Injection L83 85 Fuel Pump Auto Axle 2.72 Firestone Firehawk Indy500


Joined: 7/11/2010
Posts: 415

Thanks Rich.   I have Sunday off.  I was out trying to adapt my compressor hose to a vacuum line when you posted.  Without the proper nozzle I gave up until next time.  I'll see what I can come up with for Sunday. I should be able to get that stuff at the local hardware store.  I did have a friend suggest that I blow cigarette smoke through it but, I quit smoking this year and that just does not thrill me much and I don't think the vette should start smoking at her age. I tried the headlight bypass switch and they worked after not being run today. (yesterday's vacuum)
I believe there is a check valve at the canister that holds the vacuum separate from the rest of the system. I also had suction at the brake booster too. That bypasses the vacuum check valve I think.  So, I could still have a leak upstream.  When I started it tonight; it idled just fine.  I won't run it again until Sunday. 

Cry I'm so sad to hear the guys up north are putting away their cars. I'm still working on getting the garage project started so I can keep her out of the sun but, I do intend to keep driving her through the winter.Smile
Thanks for the advice.
Keith
 




______________

Nobody ever waves when I'm driving the Explorer.
K Woody
82 CFI Fast Idle Revisited (20/29)
 11/13/10 9:11am
crossfire1982
Former Member

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Cramerton, NC - USA

Vette(s):
black 1982 coupe slate gray interior, 350 crossfire, 1985 fuel pump, Steeroids R&P conversion


Joined: 8/22/2006
Posts: 1094

I almost hate to suggest this but since you have chased this high idle for so long it may be worthwhile to change out the ECM computer itself.  While not cheap, they are readily available.  I had to replace mine about a year ago and got it from NAPA for about $125 and my old core.  You will need to remove your old prom chip from the original computer and install it in the new one.  Just be careful not to bend any pins on the prom while changing it from one ECM to the other.
82 CFI Fast Idle Revisited (21/29)
 11/13/10 4:42pm
Phill's VetteLifetime Member
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Apache Junction, AZ - USA

Vette(s):
1982,150K,Renegade CFI,Hooker Side Pipes,85 fuel pump,Bilsteins,HD suspension, Aluminum radiator, SharkBar/w 5-Point Restraints. 3:73 gears coming soon.


Joined: 10/15/2006
Posts: 285

For the vacuum leak, check the bolts on the intake manifold top plate for tightness - I have seen them finger tight on virgin CFI's... Also, see how much play or movement you have in the throttle brackets on the throttle bodies. If both are not fairly tight, this could  likely be your vacuum leak and you'll need to get the TB's bushed. This is a normal problem on CFI's with 60k plus miles - even seen it on one with 45k miles. My 82 had 90k and bushing took care of the high idle issues for good.

Good luck!
Thumbs Up   Phill's Vette2010-11-13 13:44:50
82 CFI Fast Idle Revisited (22/29)
 11/13/10 10:43pm
kwoody
Former Member

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Tucson, AZ - USA

Vette(s):
1982 Black/Tan Leather Build Code C09E Bronze TTop CrossFire Fuel Injection L83 85 Fuel Pump Auto Axle 2.72 Firestone Firehawk Indy500


Joined: 7/11/2010
Posts: 415

Hi Chip and Phill.  I hope it turns out to be something else.  I've pretty much ruled out the TBs.  I've hit all around them with carb cleaner with not a bit of change in the idle. I have torqued the bolts on the TB/Intake top plate and the TBs and no leaks around the seal.  I decided to take it into town this AM.  Ran great.  Idled fine.  Took about 35 mins to get to work.  It was a bit cool but, 75 mph to the outskirts of town then 35-40 in between the lights for 10 minutes.  No O2 code or excessive idle.  Parked in my spot and the idle was right at 800-900 rpm. 

On the way home in the PM,  I stopped about mid-way and it was idling at 1700 rpm.  A few minutes later after I got off the throttle from about 65 mph the check engine light came on.  Turned out to be the O2 code 13. For that code to set the TPS should be not at idle. There could be something intermittent in the ECM. A vacuum leak should be pretty much always leaking - Right?  I have many years experience in component level electronics as a repair technician.  I'll have to look at the ECM closely before I replace it.

BTW - Chip is that the original gray interior? Looks great.  Phill How much clearance to you have off the ground?  Both are good looking rides!
Thanks for the thoughts.  I'll be back into it tomorrow.
Keith
 

______________

Nobody ever waves when I'm driving the Explorer.
K Woody
82 CFI Fast Idle Revisited (23/29)
 11/15/10 10:50pm
philip
Former Member

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Marana, AZ - USA

Vette(s):
1982 Silver Blue


Joined: 4/8/2010
Posts: 104

Sorry for the late reply I forgot to subscribe and have been off the board for awhile. I live 5 miles west of Sandario on Manville. The offer is still good to meet with you and see what the scanner is saying.
I'll PM my cell #.
82 CFI Fast Idle Revisited (24/29)
 11/15/10 11:28pm
kwoody
Former Member

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Tucson, AZ - USA

Vette(s):
1982 Black/Tan Leather Build Code C09E Bronze TTop CrossFire Fuel Injection L83 85 Fuel Pump Auto Axle 2.72 Firestone Firehawk Indy500


Joined: 7/11/2010
Posts: 415

Thanks Philip,
I have to go into town in the morning but, I'll give you a call after I get back to the area.  Thanks for the offer. 

Keith





______________

Nobody ever waves when I'm driving the Explorer.
K Woody
82 CFI Fast Idle Revisited (25/29)
 11/16/10 2:03am
crossfire1982
Former Member

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Cramerton, NC - USA

Vette(s):
black 1982 coupe slate gray interior, 350 crossfire, 1985 fuel pump, Steeroids R&P conversion


Joined: 8/22/2006
Posts: 1094

Keith,  thanks for the compliment but no,  its not the original interior.  I replaced the interior about 5 years ago.  
82 CFI Fast Idle Revisited (26/29)
 11/18/10 11:05pm
kwoody
Former Member

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Tucson, AZ - USA

Vette(s):
1982 Black/Tan Leather Build Code C09E Bronze TTop CrossFire Fuel Injection L83 85 Fuel Pump Auto Axle 2.72 Firestone Firehawk Indy500


Joined: 7/11/2010
Posts: 415

Thanks to all that have offered their opinions and suggestions.  I got together with Phillip and used his analyzer and experience to come up with a game plan.  The O2 sensor is producing a voltage a little lower than what I have read as spec. I think a heated O2 sensor will help keep it in closed loop.  It drops out of closed loop when I decelerate from a cruse and the O2 sensor cools a bit.  I've learned from the folks here and at the CFI Vault Forum that only in closed loop mode does the regulation of the mixture take place.   The TPS, CTS and MAP are all working.  The linkage to the TBS shows wear and the shafts have worn the lining of the connecting rods so allowing vacuum leakage to the TBS.  I really did not know how to check that.  I still think I'll remove the computer and look through that for cracked solder joints and clean the EProm socket and general electronic servicing that I know. 

The car still performs very well and I will look for a place that can do the repairs to the TBS.  I'm not in that much hurry. So, I will have to park the ride for a while this winter.  Thanks again for all the support from the members of C3VR and Philip and Chip. 

Keith



______________

Nobody ever waves when I'm driving the Explorer.
K Woody
82 CFI Fast Idle Revisited (27/29)
 11/20/10 5:34pm
philip
Former Member

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Marana, AZ - USA

Vette(s):
1982 Silver Blue


Joined: 4/8/2010
Posts: 104

Keith one thing that can be done is to remove the IAC solenoids and clean any carbon build up from the pintle and in the air passage. We can do that in my shop if you like as soon as I get the Nova on the road again.
82 CFI Fast Idle Revisited (28/29)
 11/21/10 1:47am
kwoody
Former Member

Send Private Message

Tucson, AZ - USA

Vette(s):
1982 Black/Tan Leather Build Code C09E Bronze TTop CrossFire Fuel Injection L83 85 Fuel Pump Auto Axle 2.72 Firestone Firehawk Indy500


Joined: 7/11/2010
Posts: 415

Thanks for the offer Philip.  It is nice to know you and thanks for the help.  I drove down to the pecan festival today and it was nice to open her up on I-19.  Speed Limit 75 - traffic flow 85.  There were pick up trucks and SUVs passing me at 85!  The car performs great on the road.  The idle is irregular and for the most part is somewhere between 1000 and 1200.  It did get stuck up at 1500 rpm so, I have decided to look into the brushing service from DCS.

              http://www.crossfireinjection.net/about_us.htm

I think it will be a while before I send them in but, I have an inquiry in with them.  I will let you know what I find out.  One can send in the cores and get serviceable replacements or request return after service of my original cores. I have not checked for matching numbers on this car but, the previous owner gave me all the information he received from the original owner.  The biggest thing replaced was one of the bronzed T-Top after a break-in event. Tongue

I thought I had a place to send in the complete units but, does not look that way on my recent searches.  I'm still reading and learning on the CFI Vault page.  The DCS site also has some information available under the "How to" section.  I will post what I find out.  I'm thinking that cleaning the IAC won't hurt.  Thanks again.



______________

Nobody ever waves when I'm driving the Explorer.
K Woody
82 CFI Fast Idle Revisited (29/29)
 11/21/10 12:03pm
philip
Former Member

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Marana, AZ - USA

Vette(s):
1982 Silver Blue


Joined: 4/8/2010
Posts: 104

The DCS site was informative. Some nice products and services offered too.
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