04-30-2017, 08:46 PM
you have this G13 engine? this is stock setup you have this TBI engine G13, just like this schematic shows>?
http://fixkick.com/sammi-stuff/late-sammi-efi-94.jpg
This TBI engine always races with vacuum leaks, (that means all leaks in excess of ISC controls (authority) results in racing idle, hot. 800 +-50rpm is spec (750 to 850) is ECU job to keep it here.
In idle up mode, (idleup pin on ecu active,the RPM goes near 1000. for many things(PS overload,Head lamps on, heater fan on, defrost fan on, AC/on)
a small leak does not do that, that is because a working ISC closes and hides said leak.
400 rpm is 1/2 normal (is a warning something is very very wrong)
low idle has many causes, huge actually
1:; someone set spark timing way off. or did so for below.
2: cam belt slipped
3: Gross engine misfire. (bad spark?)
4: EGR stuck open, if closed its not this.
gross power loss. for many reasons, misfire, low compression (see#2) low fuel pressure, clogged TBI injector, clogged fuel filter (in both cases partial clogs)
5: gross power loss, CAT melted.
6: map dead, (rare as hens teeth) but hose can fail to it, easy, vacuum hoses,even seen them melt, the rubber in hose goes to gooey, and collapses.
7 : engine never gets to 180f and floods
8: ECT bad. lies to engine, and tells engine engine is cold when is 180F. or more.
9: a dead ISC only causes, wrong RPM at idle,never loss of engine power. (it does other things but are while driving, like anti next snap mode, when lifting foot off throttle fast)
sounds daunting right?,. sure, but is only a few tests with tools and gauges.
http://fixkick.com/sammi-stuff/late-sammi-efi-94.jpg
This TBI engine always races with vacuum leaks, (that means all leaks in excess of ISC controls (authority) results in racing idle, hot. 800 +-50rpm is spec (750 to 850) is ECU job to keep it here.
In idle up mode, (idleup pin on ecu active,the RPM goes near 1000. for many things(PS overload,Head lamps on, heater fan on, defrost fan on, AC/on)
a small leak does not do that, that is because a working ISC closes and hides said leak.
400 rpm is 1/2 normal (is a warning something is very very wrong)
low idle has many causes, huge actually
1:; someone set spark timing way off. or did so for below.
2: cam belt slipped
3: Gross engine misfire. (bad spark?)
4: EGR stuck open, if closed its not this.
gross power loss. for many reasons, misfire, low compression (see#2) low fuel pressure, clogged TBI injector, clogged fuel filter (in both cases partial clogs)
5: gross power loss, CAT melted.
6: map dead, (rare as hens teeth) but hose can fail to it, easy, vacuum hoses,even seen them melt, the rubber in hose goes to gooey, and collapses.
7 : engine never gets to 180f and floods
8: ECT bad. lies to engine, and tells engine engine is cold when is 180F. or more.
9: a dead ISC only causes, wrong RPM at idle,never loss of engine power. (it does other things but are while driving, like anti next snap mode, when lifting foot off throttle fast)
sounds daunting right?,. sure, but is only a few tests with tools and gauges.
http://www.fixkick.com