IIRC there are two way to get air in at idle - a small hole in the center of the TB (not sure if that was still used in our years) and/or the IAC. I'm told a count of "20" is good; WinALDL will measure that.
[RICHR]
[RICHR]
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- #42
T
tigmaned
Guest
Rich
lost me on the count "20"?? what do you mean?
i am going to take the IAC value out tonight, check the pintel length and clean it again if needed and reset it one more time. and check the F/P.
ED
lost me on the count "20"?? what do you mean?
i am going to take the IAC value out tonight, check the pintel length and clean it again if needed and reset it one more time. and check the F/P.
ED
WhalePirot
Well-known member
change the O2 sensor
Seems we're about to make butter with all the churning. I'd check the miss you mentioned at idle. Check for equal RPM drop as you pull each plug wire to see if one is misfiring. Each wire's resistance can be measured with a VOM. You may be able repair any high-resistance (open) plug wire by removing the spark plug end and cutting off about 1/2", then reinstalling the terminal.
I failed, then passed a Ca. SMOG check after (only) resetting the ECM (remove power for >10 seconds). Seems it had learned some bad things someplace; like me. :ugh While your vacuum is in the normal range, a modded engine's ECM, with lower than normal vacuum, will incorrectly 'block learn' that it needs more fuel.
The purpose of the vacuum line to the FP regulator is to reduce fuel pressure, from the (set) maximum, during high vacuum conditions, like deceleration or IDLE. Your cat and O2 sensor may have been fouled by the previous owner's removal of it, causing a rich runner under high vacuum.
I have some digital pics of an '87 which may show proper line routing to assist. Most are Callaway, though.
W.R.T. the PCV: If it rattles when you shake it, it is probably okay, but you can clean it with carb spray. It's a simple, vacuum opened valve.
I believe that good detergent gasoline is more important than the octane. However, I have asked local shops which fuel tests best. Absolutely, have the car, AND THE CAT nice and warmed up with moderate driving before the test.
Do any shops do pretests for emissions?
Seems we're about to make butter with all the churning. I'd check the miss you mentioned at idle. Check for equal RPM drop as you pull each plug wire to see if one is misfiring. Each wire's resistance can be measured with a VOM. You may be able repair any high-resistance (open) plug wire by removing the spark plug end and cutting off about 1/2", then reinstalling the terminal.
I failed, then passed a Ca. SMOG check after (only) resetting the ECM (remove power for >10 seconds). Seems it had learned some bad things someplace; like me. :ugh While your vacuum is in the normal range, a modded engine's ECM, with lower than normal vacuum, will incorrectly 'block learn' that it needs more fuel.
The purpose of the vacuum line to the FP regulator is to reduce fuel pressure, from the (set) maximum, during high vacuum conditions, like deceleration or IDLE. Your cat and O2 sensor may have been fouled by the previous owner's removal of it, causing a rich runner under high vacuum.
I have some digital pics of an '87 which may show proper line routing to assist. Most are Callaway, though.
W.R.T. the PCV: If it rattles when you shake it, it is probably okay, but you can clean it with carb spray. It's a simple, vacuum opened valve.
I believe that good detergent gasoline is more important than the octane. However, I have asked local shops which fuel tests best. Absolutely, have the car, AND THE CAT nice and warmed up with moderate driving before the test.
Do any shops do pretests for emissions?
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tigmaned
Guest
so how long could it take to wreck a new cat if the vacuum line was off the FPR. but it dosen't seem to be laking power? ask the 2 Acura's whos doors I blew off!!! BUT i have no idea how long the vacuum line was off the FPR and or why, since i don't see it leaking any fuel or smell any fuel from it? but i did notice when i test the fuel pressure test with the vacuum line on it was 39psi and vac line off it jumped to 44psi, so thats alot more fuel for the engine to burn or not burn and feed into my one cat. the old owner told me he thought it had the pre-cats, but it doesn't now, but all the exhuast was changed, and no idea on the O2 sensor so i will change that cheap part just in case. plug wires are on the way and will check the plugs. (any body ever try runnig the next hotter plug it calls for?) i will run that emission additive to my gas like it say to clean the system.
there another 1986 vette for sale not far from were i live, i think i am going to check it out and take a few digital of things under the hood, well if they look right??
there another 1986 vette for sale not far from were i live, i think i am going to check it out and take a few digital of things under the hood, well if they look right??
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- #45
T
tigmaned
Guest
well i changed the O2 sensor, put new accel 8.8mm plug wires on. rechecked the emissions sticker and my vacuum lines and i think i have them right. but still getting a little miss and or stumble when she settles down at a idle? no codes coming up.
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