Code 35
Printed From: West Coast Fieros
Category: Technical Topics Forum
Forum Name: Technical Questions and Discussions
Forum Description: Got a technical question about your fiero? ask it here.
URL: http://www.westcoastfieros.com/forum/forum_posts.asp?TID=3493
Printed Date: 04 December 2024 at 6:14pm
Software Version: Web Wiz Forums 12.01 - http://www.webwizforums.com
Topic: Code 35
Posted By: Fieroman88
Subject: Code 35
Date Posted: 07 July 2014 at 8:38pm
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Well we'll see if anyone has some ideas as I'm still
scratching my head ( and The Captain is as well) HIS, NOT MINE. 2 years ago I went after an exhaust leak on the inboard side of the 2.8. Though I can't remember if I had to pull the head for(broken exhaust bolt)that must have been the case as there is no reason to have to remove push rods and reset valves for anything lesser that that. After putting it back together ( yes I torqued the head) I developed a code 35 which is a vacuum leak. The car went away for 20 months at that point. Now its out and I checked out all the lines and there is no leak found. So since I wasn't totally satisfied with the setting of the valves ( not sure if they were set right)and that the vacuum leak could be anywhere below the plenum, I gave in and tore it apart again. Resealed everything 150% and reset the valves. No I did not re-torque the head as I trusted it was correct and sometimes re-torqueing isn't a good thing to do on heads. Now that it is running again I am still getting a code 35. I put the scan tool on it and the IAC starts at 70 or above and eventually drops to zero ( which means it has attempted to shut off all extra air ( thus vacuum leak) I checked the readings against the other 2.8 and all is good except for the Idle Air Control (IAC) I then rechecked and found that it was a 70 (perfect) and was holding. Great!! Checked again later and it went back to zero. No good. I checked the vacuum at the port off the plenum that faces the distributor and it is the same at 18 pounds vacuum. ( compared to the other car) All the spaghetti lines were checked and there is no leaks. Hose into the valve cover on the inboard side has a tight fit so it isn't leaking there, nor at the PCV point. The 3/8 hose into the base of the throttle body that runs to the inboard valve cover has a nice snug fit, so its not that. Thinking about changing out the throttle body and components, from a spare engine to see what results I get. So at this point I am not frustrated but rather concerned as this issue is bothering me. Any ideas? ------------- Fieroman88 |
Replies:
Posted By: Patrick
Date Posted: 07 July 2014 at 9:41pm
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What RPM is it idling at when warmed up? I assume it's higher than it should be. The first thing I'd check is the flexible metal tube that goes from the EGR valve to the underside of the upper intake. Those EGR tubes always eventually start leaking. The easiest way to eliminate this as a potential source of a vacuum leak is to temporarily block it off with a piece of tin can between the tube and the intake and see what happens. |
Posted By: Fieroman88
Date Posted: 07 July 2014 at 10:01pm
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Hey the problem is resolved Wow. I happened to see my
neighbor outside who is a real mechanic. So I asked Randy can I pick your brain a bit and he came over. So looking over it and in a few minutes pops off the air intake hose from the air filter,takes a look of the adjustment screw which I thought was out all away, loosens it a bit more, pops the throttle a couple of times, puts his finger down the throttle body assembly and pushes the butterfly closed a bit, and says the butterfly is not closing up on my way. It can close more, and they do wear out. so we took another throttle body off a spare motor that I had, and he says this one is closing up much better and feels better than that one so I would change it. When he pushed down on the butterfly, the IAC numbers came up to where they should be. Wow problem resolved. Maybe I didn't have to take it all apart again, but I do know that motor better now because of it, and I know my valves are set perfectly. Thanks Randy and to Patrick ------------- Fieroman88 |
Posted By: Patrick
Date Posted: 07 July 2014 at 10:08pm
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Glenn, I suspect someone at some point messed around with that throttle stop screw... which should never have been done. It's set at the factory and it's not supposed to be touched.
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Posted By: Fieroman88
Date Posted: 07 July 2014 at 10:26pm
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Just so very happy to have it: all running good.😀 ------------- Fieroman88 |
Posted By: Fieroman88
Date Posted: 07 July 2014 at 10:30pm
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Remember it wasn't so much the setting of the screw as the
throttle body butterfly is worn out. ------------- Fieroman88 |
Posted By: Patrick
Date Posted: 07 July 2014 at 10:38pm
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Glenn, how many kilometres on that '88 GT? In 15 years on Pennock's, I don't believe I've ever read a post there about a Fiero throttle body (2.5 or 2.8) with a worn out throttle body butterfly. I suppose it's possible, but I think it would have to be an awfully high mileage car. |
Fieroman88 wrote:Posted By: Fieroman88
Date Posted: 08 July 2014 at 10:51pm
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Well update to the issues. Changed the trottle body with
another including IAC and TPS installed, and running much better. Put old IAC into this throttle body, and issue came back badly, conclusion is realistically it was the IAC acting up and not working at all, but throttle body could be an issue, but I'm not putting the old one back in to find out. This is the black 87 GT. 202k ------------- Fieroman88 |