SpooledupRacing

OK I did not search it but I was just looking for a quick answer. On my 86' N/A 5spd I have lostthe high idle warm up.

I use to be able to put the car in neutral with the clutch NOT IN and the car would rev to like 3k for 15 seconds or so then fall to normal now it dont do it and I was curious what would cause this to stop doing it?

Should I want it to do it or not?

I am sure this has to do with the warm up bottle on the pass side firewall (with coolant in it) and I know many people remove them but mine has always worked has coolant in it and now wont do it.

any info would be great, maybe if I should pull it a litle how to?

I know there was a service bulliten on removing it however if there is no real need to move it then I prolly wont as of now

socalrx7racer

hey man i own an 88 gxl and i actually still have the thing your talking about, the only thing is mines kind of touchy, it'll only rev up for the accellerated warm up when its really cold outside, when its warm out it'll only rev up to like a grand to 1500, and then when its super warm out and i haven't started my car all day i'll go start it and most of the time it'll just chill at idle........now i know all this doesn't make much sense because the thing should do it untill the coolant gets warm enough to melt the wax but mine seams to have a mind of its own.......my advice......if it doesn't do what you want just hold your foot on the gas and warm it up manually, thats what i do.

stevej88na

Check out the first graph on this idle system overview:

http://howto.globalvicinity.com/gv_w...i=60&co=1&vi=1

My understanding is this: The 3k rpm for 17 seconds happens when you crank between 59F and 98.6F. It's mainly the BAC and AWS (air bypass solenoid on S4) adding air on top of what the fast idle mechanism and air adjust screw are already contributing. The BAC varies its air input to maintain that 3k, so it's probably not maxed out. After 17 seconds, the idle drops to just the fast idle mechanism (FIM) plus air adjust screw. The FIM's air contribution decreases until the coolant is fully warmed, and then the basic idle is up to the air adjust screw alone. Beyond the basic idle, the BAC increases idle to compensate for loads, like air conditioning.

So, when it's really cold, your idle will probably be between 1500 and 1400. When it's warmer, it will have the 17 second 3k idle, then drop to between 1400 and 1200. When it's hot, it will probably be somewhere between 1200 and 750.

SpooledupRacing

ok but my point is it should be doing the 3k rev and it dont.

is there something to look for that may be bad?

stevej88na

I was just pointing out that sometimes, by design, it won't do the 3k rpm increase, and also pointing out some possible reasons for socal why his idle might change from time to time.

I assume you've already tapped the diagnostics plug, but if not, do it, and fix whatever it says is bad. Here's the info for your S4:

http://howto.globalvicinity.com/gv_w...i=39&co=1&vi=1

SpooledupRacing

I figured there is nothing wrong if the engine light dont come on
thx for your help.