High idle (Page 5/6) Yellow-88 SEP 20, 07:52 PM One point mentioned a few times is about the throttle not closing all the way. Is the spring doing it completely, or can you close it a tiny bit more by hand? Is there any tolerance in the throttle cable length? Does it close better with the cable disconnected? How about dry throttle parts desperate for some oil? Don't be afraid to use some WD40 and a brush, with an air hose if you have one, to get every moving part moving freely. Patrick SEP 20, 08:12 PM quote Originally posted by Yellow-88: One point mentioned a few times is about the throttle not closing all the way. Is the spring doing it completely, or can you close it a tiny bit more by hand? Is there any tolerance in the throttle cable length? Does it close better with the cable disconnected? If we look past the dirt , it appears that the TBI's butterfly valve is fully closed. quote Originally posted by Patrick: There's an awful lot of dirt on the "clean" side of that air filter canister/TBI gasket. It should be absolutely spotless. Your poor engine! Scuba_steve45 SEP 20, 09:15 PM At one point I thought that mightve been the problem but I later confirmed that it closed completely and everything moved fine/nothing was binding. I probably will oil everything still though so thank you. quote Originally posted by Yellow-88: One point mentioned a few times is about the throttle not closing all the way. Is the spring doing it completely, or can you close it a tiny bit more by hand? Is there any tolerance in the throttle cable length? Does it close better with the cable disconnected? How about dry throttle parts desperate for some oil? Don't be afraid to use some WD40 and a brush, with an air hose if you have one, to get every moving part moving freely. cartercarbaficionado SEP 20, 10:24 PM quote Originally posted by Scuba_steve45: At one point I thought that mightve been the problem but I later confirmed that it closed completely and everything moved fine/nothing was binding. I probably will oil everything still though so thank you. please provide more pictures of what modifications you have done to the engine and if you think you killed your ecm or tbi I do have some sitting around as long as a 84 ecu will work in an 85 Yellow-88 SEP 21, 09:35 AM OK. The throttle plate closes completely. No vacuum leaks in any of the tubes. At this point it looks like an IAC issue. Crud in the seat not letting it close as far as it want's to? I suppose there can be a failure in the "motor" or the power to it but personally I'd clean both the valve and the electrical connector first before jumping to extreme conclusions. Most problems are actually simple stuff. Here is a link to an IAC thread. https://www.fiero.nl/forum/...110502-2-093097.html Scuba_steve45 SEP 21, 12:15 PM Okay I’ll try cleaning it today and go from there. I just found another thread of someone having the exact same issue as me and the iac valve and everything just needed cleaned so hopefully this fixes it. quote Originally posted by Yellow-88: OK. The throttle plate closes completely. No vacuum leaks in any of the tubes. At this point it looks like an IAC issue. Crud in the seat not letting it close as far as it want's to? I suppose there can be a failure in the "motor" or the power to it but personally I'd clean both the valve and the electrical connector first before jumping to extreme conclusions. Most problems are actually simple stuff. Here is a link to an IAC thread. https://www.fiero.nl/forum/...110502-2-093097.html Scuba_steve45 SEP 21, 06:03 PM UPDATE: I cleaned the IAC and it idles right around 900!!! I understand I have to drive it a few times over 35mph to get it right but this is awesome!! Thank you all for your help! Patrick SEP 21, 06:29 PM quote Originally posted by Scuba_steve45: I cleaned the IAC and it idles right around 900!!! If the IAC valve was gummed up with crud and it couldn't close, you in essence did have a vacuum leak, as a surplus of air was being allowed to enter the intake system. I bet dollars to donuts that a lot of that grit we see in your photo of the TBI has worked its way into the IAC system, and resulted in the valve becoming stuck in an open position. If it was my engine, I'd be removing the TBI unit to thoroughly clean it, as I wouldn't want to be washing grit out of the TBI unit and into the intake and eventually into the combustion chambers. Scuba_steve45 SEP 21, 06:52 PM I will start looking online for the gaskets and stuff and get to cleaning soon! Thank you! quote Originally posted by Patrick: If the IAC valve was gummed up with crud and it couldn't close, you in essence did have a vacuum leak, as a surplus of air was being allowed to enter the intake system. I bet dollars to donuts that a lot of that grit we see in your photo of the TBI has worked its way into the IAC system, and resulted in the valve becoming stuck in an open position. If it was my engine, I'd be removing the TBI unit to thoroughly clean it, as I wouldn't want to be washing grit out of the TBI unit and into the intake and eventually into the combustion chambers. 82-T/A [At Work] SEP 21, 10:14 PM quote Originally posted by Scuba_steve45: I will start looking online for the gaskets and stuff and get to cleaning soon! Thank you! How comfortable are you with rebuilding the TBI unit? There's a rebuild kit that's about $50 bucks... it's not hard at all to do. I'd just buy some brake cleaner and after disassembling it, I'd blast the heck out of it.