93 sidekick - no start - no spark

[ervit]

Hi folks. New to forum, so thanks! My sidekick abruptly refused to start after sitting through the day. Eventually checked out coil, distributor, etc., and after pushing wires and connectors under intake manifold around, it started. But only for a while! It later refused to start again, and I have no luck finding a short, loose connector, etc. It gave no sign of impending doom - ran great before, and in between bad starting episodes. I tried to test cam position sensor, and igniter, but got full battery voltage on one lead and 5 V +/- on the other, which shouldn't be the case according to my manual. That was before it started again, so I doubt that it's the problem somehow. Any thought? I'm not mobile now, so it will be grief to get an ECU to test out. Anything you can contribute would be greatly appreciaed.

Cheers!

[lord_galathon]

1-does it crank? if yes and by moving wiring around it started but then died your problem is likely electrical.

If no then you're looking at your solenoid, starter relay, switch etc.

Start by that.

[ervit]

Thanks for the reply. I don't think there's any issue with the starting circuit. It has a relatively new battery, alternator and starter, and it never hesitates to spin up quickly when the key is turned. I also poured some fuel in the top of the throttle body to see if it was something in the injector circuit, but that didn't make it catch, or sputter even, so it is probably getting fuel. It has never run erratically, even between these no-starting incidents, so I don't think it is a timing issue. There is definitely no spark from the distributor end of the coil lead, but the coil resistance is within specs, and it did start and run fine again after the first incident, so I don't think it is the coil. I'm thinking either the ECU/PCM "brain", or a grounded/shorted wire or bad connection between the ECU and the distributor or coil. I didn't notice any smell or heat coming from the ECU under the dash, but don't know if that is something that always accompanies an ECU failure.

Thanks again.

[lord_galathon]

in my experience ECU failure will be accompanied by a clicking sound from under the dash and the injectors.

I would check your spark. You have crank, if you have gas smell you'll have gas, if not check your electric lines to the fuel pump.

A dear friend told me that the fuel pump electric harness runs through the drivers' side rear wheel well panel and there's a like 14 way connector in there that includes your taillights and fuel pump.

That can corrode and go bad.

If you have gas (gas smell when cranking) you may have no spark; spark plugs, wires, coil, etc.

Three things keep your motor running;

-crank
-gas
-spark

and in the case of some of our older Zukis, prayers and love.

[ervit]

Just a quick update. It is now running great. It turns out to have been the ECU all along. Everything else is fine. FYI the ECU didn't smell bad, or look distressed in any way when I took it out, or give any indication that it was about to take a vacation.

I did get a good deal on a rebuilt ECU from a guy near Vancouver, so if anyone has any ECU issues in future, I'd try Empire Auto wrecking in Abbotsford - ask for Lou.

Thanks very much for the help. It felt good to know that others were trying to help while I'm dealing with this. Thanks again!

Cheers

[jtgh]

fyi;
the ECU has 100,000 + of transitors , anyone of which
could kill the car.
the smallest of which (microns) will not be smelt .

in reality it is a powerful micro computer with large transistors that fire the ignition and the injectors.

it also has an internal voltage regulator that can go out and make the whole thing go dead.

for others, when there is no spare or injection
the ECU is bad or the CPS is dead.
if the drummer boy (CPS) is alive then the ECU will use a very dump startup set of rules.
it will ignore most sensors and just start up.
however the TPS must be good.

IT has 3 modes, start, run cold and run hot.
each mode is vastly different.


I put this here, for other that have this common problem.


CPS , crank positon sensor.
or CAS , crank angle sensor or cam angle sensor.
the ECU must know where your crank shaft is at all times !!!
TPS is throttle sensor,
if the ECU cant tell where the throttle is sitting it must rely on the MAF or MAP to find out what you are doing with your right foot.

crank postion, throttle (AIR VOLUME) = start

somes times the main relay goes dead and with it the ECU gets no power source.
and the same results.

[jtgh]

http://www.suzuki-forums.com/attachm...t-efi-jh-w.jpg
this should help
a road map, not EVR = EGR , my typo on drawing.

[yoeddie]

thanks for the info