I have searched for this topic and cant seem to find anything on it.
Maybe it's my spelling. hummmm
Anyone have any idea why a 1990 1300cc Injected engine would surge while warm? It does it at any RPM and only while warm. When the engine is cold, it does not surge but does run at a high rpm until it warms up to operating temp. When the RPM drops, it starts surging.

:beer: :beer: :beer:

Mines a carb so this may or may not help...

Vacuum lines...are they all attached/clean/and routed right????
Untill I redid my vacuum lines I had a surging problem when cold but went away when warm.

According to the FSM, it could be a variety of things...

1) clogged fuel filter
2) faulty fuel pressure regulator
3) faulty ECM
4) faulty ECT valve

To go thru all of the diagnostics here in a message would be cumbersome, at best. You´d be well served to get your grubby hands on an FSM.

BTW, you´ll need the supplement for the EFI stuff. It´s not in the standard FSM...

HTH.

:beer: :beer:

check the timing just a thought


dan :massey:




:flipoff2: :flipoff2: :flipoff2: :flipoff2: :flipoff2:

Originally posted by AkDale
I have searched for this topic and cant seem to find anything on it.
Maybe it's my spelling. hummmm
Anyone have any idea why a 1990 1300cc Injected engine would surge while warm? It does it at any RPM and only while warm. When the engine is cold, it does not surge but does run at a high rpm until it warms up to operating temp. When the RPM drops, it starts surging.


the only comfort is, you're not alone.:flipoff2: i have a '91 efi and mine has been doing the same surge thing (right between the "it's still warming up" and "it's fully warm") stage for the past 3-4 years.
i have heard of many people mention this, including the Tracker/Sidekick guys, in the 1990,1991,1992,1993 range (at least) so it's definately not totally unique.

i have never been able to duplicate it for a mechanic-it has to be left at their shop overnight so they could start it up from cold and see when it begins to idle down. that's when mine does it.
being my daily driver i could never find time/money to do that, (and they never convinced me they would diagnose it properly anyway.)

the FSM and Supplemental do not address that specific problem the way it happens with mine, it's rather vague in that regard.

it very well could be something as simple as the thermostat being knackered, or a sensor that gives info to the ECM. but who has the time/energy/money to start pulling stuff out to check on specs 'n things, if it still works and there's beer in the fridge, right?:beer: :rasta:

ok guys here's the repair for the surge that happens during transition from cold engine to warm engine.

First confirm No vacuum leaks.

Second hope that no one has screwed with the factory set base idle screw.

Third confirm proper voltage out of the TPS sensor

And fourth Just skip to this step:smokin: on the side of the throttle body is the idle air bypass for cold idle it uses the wax pellet to close the air off and just like the wax pellet in the carb engine chokes it gets lazy. What this causes when it doesn't close as fast as the computer expects is a hunting condition.
The fix is two remove the three screws holding a cover on and inside you will find a washer that is threaded to the alluminiun housing. Scribe mark and turn this washer one full turn clockwise.
This is all I have done on several zuki's. Minor adjustment maybe required to get the right amount of cold fast idle.

hey cheers, Moose. thanks for the heads upon that! i will definately give that a try when i get off work:)

ps- being an extreme lurker on the island board, just thought i'd mention i really liked the weldunator project:beer: :beer:

Great let me know how many Zuk's this fixes:smokin:

What a wonderful person-- I fixed 3 zukes today-- 2 of my four and one of a friend. He thinks that I really know my stuff. Thanks Moose

i'm lazy and haven't done mine yet:flipoff2:

Just a 5 min fix :-):rasta:

i'm REALLY lazy.:flipoff2: