Ok.. Got home last night and tested the coil.. (Connected to the system)No Spark
Tested against battery with Jumpers.. GOT SPARK
So the coils good.

Also got to thinking about what Fasteddy said.(if there is no spark the injectors don't work eather) So Figured maybe this also works in reverse. So tested for a fuel problem..

NO power at fuelpump.. So I jumped it off a dome light to get the fuelpump working .. and the fuelpump works FINE..

So i then attempted to start it with the fuel pump jumped and running.. STILL no luck.

Then removed the ECU.. Tore it down . and put it under a magnified Desk Lamp for inspection.. Its real clean.. No broken or burn connections.

Ok so I'll break it down to things I know are good,

1)coil
2)fuelpump
3)all fuesable LINKS.. (removed all and replaced)both Main and Sub
4)Connections to fuel pump and ECU (but not ECU itself)

Things I know are broke

1)no power to the coil
2)no power to the fuelpump
3)the obvious..(Truck don't start)

As far as the 'Quote'(stupid box) ha.. Next to the coil. I'm wondering if I can do the same test against the coil jumping of the battery. Only this time going through that box as a starting point with the coil connected to it? Its T's back into the system between the box and the coil.. so i didn't want the juice to get back through the ciruit.

I'm guessing i'm gonna have to blow my lunch money on a used ECU. To At least rull out. But would really like to rule out everything else before I drop that kinda dough.

So any Idea's on a next Step on this one?

Again Thanks for all the feedback .

I'd be real suspicious of the electrical portion (rear half) of the ignition switch.

Frank

I had a similar problem last year. Drove to Walmart just fine - got back in and wouldn't start! Nothing! Notta! Nil! I could just barely see what looked like a burn on the ecu board. I found company on the web - http://www.ecmtogo.com/ and sent it in for repair/replacement. Now it works fine.

Please understand, I DON'T EVER WANT TO GIVE FALSE INFO, but the parts guy said that a bad idle speed control servo can result in your ecu going bad. The return box even came with a note suggesting this be replaced (which I did).

Has anyone ever heard of or experienced this before?

Experienced.... no. Heard of it.... yes, several times.

Still, coil primary voltage has nothing to do with the ECU - it's a function of the key switch and electrical connections... starting with the battery (+) and (-) and continuing through several (+) connections and ending at the coil primary connector.

You can completely remove the ECU and still get coil primary voltage if all else is in order.

Frank

The Mitsu ECUs have always had problems dealing with open outputs. That is why they suggest checking/changing the idle speed servo. I amwondering if the relay next to the ECU could be bad?

Ed

The relay doesn't control power to the coil. The only things in the coil primary circuit are the battery connections, the 100A main fuse, a subfusible link, the key switch and a few connectors. I'm going from this statement:



When you test for coil primary voltage (12v), is the key switch in the RUN position? If you're unsure, try it again and make certain it's not in the ACC position...... an easy mistake to make..... I know. <img src="/forums/images/graemlins/wink.gif" alt="" />

Since this happened after washing the engine, it's possible a connector is loose, or a fuse shorted. Since the truck sat for a long time, it's possible that the key switch contacts are degraded.

Frank

Is this true? About the ECU not having control over the coil? Even the Dealer told me it sounds like a ECU problem.. But if it has nothing to do with the ECU.. That would be great..!! I was gonna buy one this weekend.

Also I may not have been clear.. I didn't wash the engine.. just the truck.. And it was running.. I was driving it around for an hour or so.. Then stopped with it running .. jumped out to grab something in the house.. was walking back to the truck and it just shut off.. No strange noises nothing ..

So in hearing that.. do you think it could still be a bad ignition switch? For it to just go while running like that?

As far as voltage to the coil.. I attemped to get voltage both by the key in the ON position .. and also had my Girlfriend in the truck starting it while i was testing it.. and still no spark with the engine turning over..

Would the ignition switch being bad also effect no power to the fuel pump.. Also tested that while both the initial turn key when the pump should turn on .. and also while turning the engine over. ?

Do you know the points to check working back to the ignition switch.. and with everything else working and having power... Could it be the switch?

There is a distinct difference between "no power to the coil" and "no spark".

If you don't have 12v+ at the coil primary, then yes - it could be the ignition switch. Download the online manual to trace the circuit.

If you have 12v+ at the coil primary, but no spark when the engine is turning over, there are several things that could be wrong..... including the ECU, coil, distributor and/or the power transistor.

Frank

When the ign is turned to on, the fuel pump should run for about 1sec, then turn off until the ecu sees a tach signal from the coil - terminal. No tach signal, no fuel injection. This avoids flooding the engine if there's no spark, and is a safety in a wreck in case of broken fuel lines.

The coil tests good for sparkin abililty per your post. What about the other tests I suggested?

Yes.. I ran those tests and posted the results earlier.. No 12V at + @ coil.. nor at fuel pump.. also tore down ECU.. visually looked good and clean.. No smells.. Tested coil.. Coil itself is good.. Also tested Fuel pump by jumping it off dome light.. fuel pump works.. tried starting it with fuel pump jumped.. still nothing..