A Number of Fun Issues!

[Garemie]

welcome !

Hey fixkick,

I bring you a tough one... I hope you like it.
is this a stock engine? many sammi are not. now... long ago engine swapped.

I put this motor in my Samurai myself. It has ran good for quite some time, this idle issue is new. It is a 1988 Samurai with a 1994 Sidekick 16v G16A 4 injectors

1994 Sidekick 16v in Samurai. Federal emissions. G16b engine, 4 injectors? or 1 injector??????[/color]

G16A - 4 injectors

Will not idle hot. (low rpm only, ?>) HOt or cold, , cold will be like 1500 , is it?)

Cold idle is proper. Starts at around 2000 for a few seconds, then drops to around 1500...then when its hot it goes to 800 and slowly goes down till it either dies or runs like a tractor at 300 or so RPM.
I have checked for vacuum leaks, nothing I can find. (vacuum leaks cause IDLE way too high on G16a, on G16b low due to MAF by passing causes)
I assume its an EGR related issue. (if the valve is closed, its not this cause it only needs t0 close, EGR is inactive at idle , on all G16s)
do you have power loss? (if yes check sparking timing of huge retard, cam belt slipped, or check compression for huge drop, 150psi normal , 80 not, same cause.

It was running perfect idle yesterday and I was able to do a proper timing adjustment using freeze timing. Is still good.

When it's able to run, (very low rpm, probably 3-400) and I try the EGR stall test, there is no response.
The EGR exhaust path is probably 100% blocked, and is not it.
if an engine ever can run at 300, most will not, and you opened the EGR it must stall instantly. or the EGR is dead, but is a distraction here. all this EGR
worry, egr closed is what we want at idle, (the ECU defeats it at idle )

I have tried another EGR that I know is good. Still no response for stall test. (if the valve diaphragm ring moves open 1/4" then closes with finger then that main EGR valve is ok
I also cleaned out the passage way pretty damn well. (head tunnel too>? and exhaust port for egr?) path is long... but lets fix the real problem
you can drive great with no EGR at all. and is a great test to prove that, defeated, shows even runs great with no EGR.
then when engine is no running great, fix egr to pass smog or to get longer life of exhuast valves (they run cooler last longer) and CAT more happy. (NOX reductions)

There was a Check Engine light before I had to remove battery, but it hasn't come back and it's been a couple days.(my guess code 51 egr dead)



Where should I start for diagnosis?

fix RPM hot idle, 800 is spec, 400 is crazy low.

i do spark timing ony because its a 5min job. if retarded the cam belt slipped as all do over 60,k miles.
or do compression.

post both good bad and ugly
what does the car do driven. good or bad. both.

Runs like a top at any speed. Maybe a slight power loss from before.

has full power?

Yes....or maybe 90% of full power...which is why I guess EGR??
misfires at cruise.
No
bogs
No
hesitates
No
overheats
No
the full story on driving, and even coming to a stop helps.
EGR love to stick open coming to a stop. (the idle switch closes, , egr is CUT dead, if it sticks open engine stalls or goes to 1/2 normal RPM)

---

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

Its a G16A 4 injector from a '94 Sidekick.

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.