1992 Sidekick-Sputtering

[Brown]

1992 Sidekick JLX. Engine sputters at about 15-20 mph. Have changed out plugs, wires, cap, rotor and coil. Also changed out o2 sensor and convertor was removed and replaced with just a straight pipe back to muffler. Still has same problem. Starts fine and idles up then back down when warm. When sputtering doesn't backfire just runs very rough.

[fixkick]

Hello and welcome !!!!! 8v or 16v?
MISFIRE (50 ways) but way less in tests. and you have idle surge. (ISC cant control idle so it hunts to find 800 and fails, repeats )
do you have full wide open throttle power up hills. or does it misfire doing that too?

if the cat is gone the EGR is now dead. I'd now defeat it.
EGR: make 100% sure the main valve is closed, then pull the vacuum hose to it and put in a golf tee at the suck side (hose going forward)
end chances of EGR causing all this horror.
next remove the FPR hose, (vacuum) does it leak fuel,? bad FPR, seems more are now failing after so long.
is vacuum steady using a vacuum gauge at idle (19"HG is typical and never bouncing)
if yes, ok, then engine is probably ok. (compression tests are better evaluation of engine)
check spark timing ? is it way retarded,? if yes the cam timing belt slipped. !!!

with EGR shut down. we reduce the MISFIRE list and lots of hair pulling.
My guess is that its gross fueling errors.
in fact its running rich, are spark tips black? yes, then this is rich misfiring.....
lean ,causes bogging.
way too rich , causes misfire (good engine, good spark, sparked timed right)

is the crank bolt set to 94ft/lbs yet, per TSB or is it at 10.
front pulley, 17mm bolt, using a 1/2 drive 17mm deep wall socket. is this bolt at the NEW spec.????? I call this the day one test.

[Brown]

Hello and welcome !!!!! 8v or 16v?
MISFIRE (50 ways) but way less in tests. and you have idle surge. (ISC cant control idle so it hunts to find 800 and fails, repeats )
do you have full wide open throttle power up hills. or does it misfire doing that too?

if the cat is gone the EGR is now dead. I'd now defeat it.
EGR: make 100% sure the main valve is closed, then pull the vacuum hose to it and put in a golf tee at the suck side (hose going forward)
end chances of EGR causing all this horror.
next remove the FPR hose, (vacuum) does it leak fuel,? bad FPR, seems more are now failing after so long.
is vacuum steady using a vacuum gauge at idle (19"HG is typical and never bouncing)
if yes, ok, then engine is probably ok. (compression tests are better evaluation of engine)
check spark timing ? is it way retarded,? if yes the cam timing belt slipped. !!!

with EGR shut down. we reduce the MISFIRE list and lots of hair pulling.
My guess is that its gross fueling errors.
in fact its running rich, are spark tips black? yes, then this is rich misfiring.....
lean ,causes bogging.
way too rich , causes misfire (good engine, good spark, sparked timed right)

is the crank bolt set to 94ft/lbs yet, per TSB or is it at 10.
front pulley, 17mm bolt, using a 1/2 drive 17mm deep wall socket. is this bolt at the NEW spec.????? I call this the day one test.

Thank You for your Info. Yes that'll be a good first day. Actually need to get a vac gauge. It's a 16v, looking forward to getting this running right. Will post my progress as I get to it....I have two jobs so free time is sometimes hard to come by......Thanks again

[fixkick]

is the check engine light on , key on. then off running:?
good luck , and hope you get fixed easy.

---

does it have full power WOT, up hills? if yes, the engines ok. (no dead cylinders, no slipped cam belt)
or does the misfire, prevent doing all that.
and is it misfiring cold and hot?

[Brown]

Plugged the EGR vacuum hose and walla..............no sputtering.

[fixkick]

a no cat car renders the MOD valve useless. it sticks open . (if still working correctly the MOD)
but in your case the MOD is closing inside "V", my guess is the red vent is clogged in the MOD,
why try to fix a useless MOD , now that the CAT is missing.?
just leave it defeated.? as it is now.



if the red vent line clogs as they all do this old.
the MOD self activates. suckings its own V valve closed.



normally the CAT back pressure , modulates the V valve and in this way, modulates the main EGR based on engine load.
with the CAT missing, there will be no correct modulation, possible.