stalls after cold start

[garino]

I have a 1998 Sidekick Sport 4x4. It runs fine when warmed up but when the engine is cold (<55F overnight) it won't idle: it just surges a bit, shudders, and stalls. It starts easily and will keep running if you give it throttle and keep it at 1500 rpm or higher. It also throws a code P0717 for "system too lean" and the long term fuel trim is at 14.1% (STFT is 0%).

Here's a short video so you can hear what it sounds like starting. The throttle was not touched during this video.

More details: vin JS3TD21V4W4104601, 4wd, auto, AC, stock except for hitch and tow bar. Carfax says it was purchased in Virginia in 1998, so I assume it's not a California car. I've had it since 2009 and have been getting it smogged here in CA every 2 years without any problems until last April. It wouldn't pass the NO test, until my fav mechanic found & fixed a bad injector, cleaned the rest, and then it passed. BUT that's when this cold start problem started and they couldn't figure it out, but when summer came, problem gone. Now winter is back (San Diego winter) and the problem is back.

If you want to see more, take a peek under the hood, maybe look up here and over there

After doing some searching for P0717 it sounds like it could be vacuum leaks, fuel pump or filter, maf, or injectors. Given that it's 20 years old, I would suspect vacuum leaks but why would it only affect cold starts?

Gary
San Diego, CA

[fixkick]

runs perfectly hot, engine, up hills. flogged hard runs great.right?
sparkplugs ok, spark wires, cap rotor fresh, not 20 years old. gapped at 0.028" never used out of box at 0.045" ever.

spark if first ,if engine itself is ok, spark needs to be strong cold , its runs richer cold so may need very good spark.
lean sure, all MAF engines can go lean , with unmeter air leaks. or just a dirty maf, clean it, with maf cleaner from 8inches away, not direct blasted.
i cant watch the video, im in Yucatan mex. now. diving'
when hot , idle at 800 ?rpm and holds there. shifted to drive, (AT OR MT BOX)? OR TURN ON BLOWER, AND HEAD LIGJTS, does RPM still hold 800 rpm hot.

the surge can be 2 things, lean surge, or the ISC cant control idle speeds so ISC surges madly to get 800rpm but idle is not active cold
The cold surge is misfiring or way too lean. (or extreme rich spark misfiring)
that 717 is hot failure not cold. its hot closed loop failure to regulate fuel rates.

the front 02 sensors can be bad. this old, easy. just front, rear is only for CAT testing,
clean maf, spark good full tuneup, the 02 , and last look for vacuum leaks.....harder... last..

[garino]

It runs smoothly hot, but up hills it lacks enough power to keep up with CA traffic going 75, but I'm not sure if that's normal for this model. It has no problems keeping up with 75-80 mph traffic on flat or slight hills.
It idles hot at 800 or 775, I checked that yesterday. I'll recheck the rpm hold with elec. load later today.

175,780 is today's mileage, i forgot to mention, and it has AT.
169,912 injectors were cleaned/replaced at last smog 4/11/17
162,197 spark plugs, fuel filter, air filter, valve cover gasket replaced 11/20/13.

I'll start with cleaning the MAF and making sure spark is good.

What do you mean by "idle is not active cold"? ISC not active?

Diving the Yucatan, awesome! I've been diving in Belize, that was an amazing place.

[fixkick]

75 no way with 95HP and 2200 lbs body, up hill... sorry but sure hills vary , LOL !
but when you flog the engine at any time, does it run right like new , when hot. I'm presuming you had it when it ran good.
ok answer is yes, that tells me the fuel pressure is probably good. (well for hills it is)
good idle controls work.
sorry I was no clear, idle RPM's cold is governed by water temp. IAC device , a funny lump there under the throttle body,
idle cold is about 1500 and reduces gradually at 150f the IAC is dead closed, no air now, from it,, at 150f+ the smart ISC takes over.(+ecu smarts)

im not sure you have good gas, is it from Mexico? (i lived in S.Diego once (navy) and we bought gas there.(not wise)
id first try a bottle of chevron Techron , in the tank, I don't like additives, but this stuff is full of hot solvent benzine, and really can work as can the gas from Chveron. (sure most top sellers USA)
it can clean the injectors. if say, you get some bad fuel. it sure can't hurt.... as some lesser brands can .'

did you get all new spark parts ? plugs,wires ,rotor cap? yet,, get mag wires
mag wires from bosch or NKG,, will help any old suzuki ,it has very weak spark so.... mag wires help that greatly.

sounds like you have cold misfire. (seems to me)

it's not the 02, its off line cold.
spark is first. ]
dirty maf\

the maf is used even at 800 rpm
and the maf barely works that slow.
and needs to be cleaned say every 50k miles
as does ISC and EGR.

if the EGR hangs up, as the love to do when old.
they can do that common to a stop and engine stalls
or you are parking and not notice the hang up. (egr main rear of intake thunnel 4)
then on restart cold the dang thing leaks, and can not idle correctly.

to prove its not that.
on cold engine push it closed by hand (it has ring at the base,flex it, and it opens and pops closed.
then pull its vacuum line and golf Tee that hose.
now see if idle is ok cold, egr defeated for just a test, P0400 will trip. driven hot, defeated, no worry. for a day.

the cold idle is misfiring.
bad spark. (DO A FULL TUNEUP)
egr hangup, (it's off line cold but must not hang)
leaking injector(s)
even a bad FPR with too high fuel pressure,

ok good luck !

PS: evidence one can get.
if one removed all spark plugs to read them
do they all look the same, cream or light tan.
or one black? or one looking very odd some other way?
or a gap so wide one can toss a hat through it ?(gear head jocks, sorry)

[garino]

It was the MAF sensor. Replaced it and now it idles and runs smooth, cold or hot. What a difference!

thanks!!

75 no way with 95HP and 2200 lbs body, up hill... sorry but sure hills vary , LOL !
but when you flog the engine at any time, does it run right like new , when hot. I'm presuming you had it when it ran good.
ok answer is yes, that tells me the fuel pressure is probably good. (well for hills it is)
good idle controls work.
sorry I was no clear, idle RPM's cold is governed by water temp. IAC device , a funny lump there under the throttle body,
idle cold is about 1500 and reduces gradually at 150f the IAC is dead closed, no air now, from it,, at 150f+ the smart ISC takes over.(+ecu smarts)

im not sure you have good gas, is it from Mexico? (i lived in S.Diego once (navy) and we bought gas there.(not wise)
id first try a bottle of chevron Techron , in the tank, I don't like additives, but this stuff is full of hot solvent benzine, and really can work as can the gas from Chveron. (sure most top sellers USA)
it can clean the injectors. if say, you get some bad fuel. it sure can't hurt.... as some lesser brands can .'

did you get all new spark parts ? plugs,wires ,rotor cap? yet,, get mag wires
mag wires from bosch or NKG,, will help any old suzuki ,it has very weak spark so.... mag wires help that greatly.

sounds like you have cold misfire. (seems to me)

it's not the 02, its off line cold.
spark is first. ]
dirty maf\

the maf is used even at 800 rpm
and the maf barely works that slow.
and needs to be cleaned say every 50k miles
as does ISC and EGR.

if the EGR hangs up, as the love to do when old.
they can do that common to a stop and engine stalls
or you are parking and not notice the hang up. (egr main rear of intake thunnel 4)
then on restart cold the dang thing leaks, and can not idle correctly.

to prove its not that.
on cold engine push it closed by hand (it has ring at the base,flex it, and it opens and pops closed.
then pull its vacuum line and golf Tee that hose.
now see if idle is ok cold, egr defeated for just a test, P0400 will trip. driven hot, defeated, no worry. for a day.

the cold idle is misfiring.
bad spark. (DO A FULL TUNEUP)
egr hangup, (it's off line cold but must not hang)
leaking injector(s)
even a bad FPR with too high fuel pressure,

ok good luck !

PS: evidence one can get.
if one removed all spark plugs to read them
do they all look the same, cream or light tan.
or one black? or one looking very odd some other way?
or a gap so wide one can toss a hat through it ?(gear head jocks, sorry)

[fixkick]

good and bad,
good fixed
ouch, cost, most expensive EFI part on car bad.
sorry !!!