bad Idle-what else can i do... ?

[phil2000]

hello syty-experts,
half a year ago i bought my ty and just love it..... exept for this
very little but non the less very annoying problem with hunting
when ideling. sometimes the engine even stalls. the main problem is:
i can't find any real coherence between any state the engine is and the
moment it idles so bad: sometimes it's just perfect, (air-condition off, of course), and then, all of a sudden, it get's real bad. It does not happen with the engine cold, which is obvious too, i guess. usually the rpm drops down to 500 when switching from D to N or P, and the ecm regulates it up again.
and then, just standing there, all of a sudden it start hunting again....
Things i did so far with kind help of the local syty-posse here in Switzerland:
New Plugs, new cap/rotor, new air-filter, new fuel-filter, new tps, both tem-sensors new, new pcv-valves, new wires (atr black beauties, no, they are not touching the downpipe), new gasket on the throttlebody-plate.
the truck is in stock condition.
i would apprechiate very much any idea for solving this problem !
but i also know that bad ideling seems to be common for these trucks, and also seems to be very hard to solve....

thanx anyway ! regards- philipp

 

[ParTyBoy]

Re: bad Idle-what else can i do... ?

hello syty-experts,
half a year ago i bought my ty and just love it..... exept for this
very little but non the less very annoying problem with hunting
when ideling. sometimes the engine even stalls. the main problem is:
i can't find any real coherence between any state the engine is and the
moment it idles so bad: sometimes it's just perfect, (air-condition off, of course), and then, all of a sudden, it get's real bad. It does not happen with the engine cold, which is obvious too, i guess. usually the rpm drops down to 500 when switching from D to N or P, and the ecm regulates it up again.
and then, just standing there, all of a sudden it start hunting again....
Things i did so far with kind help of the local syty-posse here in Switzerland:
New Plugs, new cap/rotor, new air-filter, new fuel-filter, new tps, both tem-sensors new, new pcv-valves, new wires (atr black beauties, no, they are not touching the downpipe), new gasket on the throttlebody-plate.
the truck is in stock condition.
i would apprechiate very much any idea for solving this problem !
but i also know that bad ideling seems to be common for these trucks, and also seems to be very hard to solve....

thanx anyway ! regards- philipp

check your vacuum lines for cracks, leaks, and overall wear...

Asside from that what cap/rotor, plugs are you using? start simple before moving to complex things....

 

[phil2000]

Re: bad Idle-what else can i do... ?

thanx ParTyBoy for the quick answer !

my plugs are AC R42TS, and Cap&Rotor are what the local us-car specialist
sold me as appropriate...

beside the idle-problem the truck is running pretty well, the hunting was actually already there before i changed a thing (ignition-wise/filters etc.) ...
once i a standing on the gas-pedal, everything is fine...

still working on the vac-lines though, some of them are already replaced.


regards- phil

 

[SeattleSy#1255]

may seem stupid, but make sure all the plugs are pluged into the TB...I had one shake loose and had similar problems and was trying to track something down that was easy as hell.

 

[phil2000]

thanx seattlesy...
doublechecked that, they are all where they should be...
found out that the egr-valve could be the culprit: it's quite sticky and
might be leaking.....

what about the coil ? does it affect ideling ?

thanx again & regards- philipp

 

[ed hess]

phil
if you have lots of time on your hands, search for topics created by me.
theres lots you can do while tracking this problem down. before you start make sure all your other bills are paid.

ed
Im not kidding!

 

[Thrillhouse]

My blazer used to idle badly like that, it turned out to be a combination of a bad ground in the electrical system and a half-dead fuel pump.

 

[SeattleSy#1255]

ya, I just fixed a buddy's jeep today with a horrible idle...vacuum leaks everywhere...took care of the whole problem...

vacuum leaks are very common with the old stock 12 year old hoses and elbows.

I'd start there...you going to want to replace them anyway...its not to expensive just a bit time consuming.

 

[phil2000]

thanx for the hints, guys !
i changed the egr-valve today, since it was sticky anyway- no change.

we made a intresting observation while replacing the vacuum-lines that are going with a T to the map-sensor and to the fpr: when we disconnected and closed the entrance to the tb, the engine idled perfect....
but: with new hoses to fpr and map-sensor, the problem came up again.
so, what is wrong here ? does either the map-sensor or the fpr (stock) loose pressure ? is this possible at all ? or am i missing something at all :roll: ??

thanx again for any input, regards- phil

 

[ed hess]

put avac pump to each of those separetly and i bet your afpr has a vac leak.
ed

 

[phil2000]

thanx ed, that was quick ! 8)
i will try that....
ok, and there it goes, another 120 bux for a afpr...

phil

 

[ed hess]

was that the problem?
ed

 

[phil2000]

i don't know yet, ed, i am not in the garage anymore...

but it looks pretty much like it, so that's why i am looking for other unpayed bills now....

but i keep you posted, for shure.

phil

 

[phil2000]

ok, it was not the fpr.....
and: of course ideling is better with the map-sensor disconnected, because it is way too rich then.....

continued chasing vac-leaks: the axle of the throttle-plates (where it leaves the tb) is loosing pressure... is this normal ??

thanx & regards- phil

 

[FLSY2730]

My bad idle was cured with rechecking the rocker arms, they were a little out of adjustment, and that cured the idle problem.