Help !

[Tijeff]

Ok folk's here is a hard one! (sorry for my bad english)

My 1.3l SOHC Pontiac Firefly 1999 just stop working. 180000km, I bough this car at 150000km

For about the last 2 weeks, I felt somehow degraded performances. I sometime had to rev-it to 4000-5000rpm in order to be able get some power to clutch on 1st gear(2000rpm and les were use-less) This problem was intermittent and was disappearing as the motor was warmer.

About a week ago I got a P0172 error code witch mean: (Fuel System Too Rich). according to : Troublcodes.net Trouble Codes OBD & OBD2 Trouble Codes and Technical info & Tool Store. By BAT Auto Technical I changed the air filter that was pretty dirty, and reset the error code , Error code never came back. At that point, I think performance came back a little but I'm not that sure. Maybe this is not related to my actual problem at all, but who knows.
Yesterday, after a good 80km run on the highway, I stopped at a red lithe, and while trying to accelerate my motor just stopped, I tough it was simply my low performance issue, but the motor never started since. The starter turn the block but the motor won't start.

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First I must say that accurate information about my motor is hard to find. G13B is written on my block, but it is a SOHC, this is somehow contradictory with wikipedia: Suzuki G engine - Wikipedia, the free encyclopedia Because my car look more like exactly like the G13BB wikipedia definition:

G13BB:
The SOHC G13BB has electronic MPFI Multi-point fuel injection, generating 56–59 kW (75–79 hp) at 6,000 rpm and 104–115 N·m (77–85 ft·lbf) at 4,500 rpm. The G13BB has 2 double coil packs directly bolted on the valve cover, although early models still had the coil packs mounted to the left side of the head, traditionally where the distributor was located.

My car is exactly like:
TeamSwift • View topic - 2000 firefly, 4cyl no spark (help!)

I have the chilton book :
Chevrolet Sprint & Metro, Geo Metro, & Suzuki Swift 1985-2000: Chilton Editors: Amazon.ca: Books
But it does not really cover my motor, actually it does not cover my car at all

I've gather much of the information displayed below (they are 3 JPG attached, ) in a 2008 version of the ALLDATA software a friend of mine has. That was the only reliable information source I found

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I've check for fire, NO FIRE

I’ve check the timing belt, it looked like new , and was well tensioned

I've change the spark plugs

The fuses in the motor are fines, all fuses under the steering wheel are fine to.

I inspected the fuse block, and the relay block for rust and looking for faulty ground connection, looks brand new.

I Verified the relays, they all click when 12v is applied to coils, are they get contact continuity on the ohm meter.

I suspected the coil-pack because they look pretty rusted. This car has a funny setup, there are 2 coils , and each coil drive 2 spark plugs simultaneously. As I understand it, only one spark out of 2 is actually useful, and the high voltage spark voltage is applied to the 2 spark plug positives at the same time. Actually the high voltage flow from one spark plug to the body , from the body to the other spark plug and back to the coil. Weird setup, but a working design. From the manuals I’ve seen, the coil-pack 3 pins order vary depending on the model, but basically The coil-pack 3 pins connector get 12v, ground, but does not seem to get a fire signal from the ECU.

I've done a home-made test to verify my coil unit. Actually those coil have a power transistor inside, and the ECU is driving this transistor to trigger the coil that fire a sparks. I do have some basic electronic knowledge and managed to get some spark out of those little beast. To do this test you need 3-4 aligator-clip wire, a 1kohm resistor and a 9-12v source ( preferably fused under 1amp so you don't blow up anything) . A 9v battery would be the safest way. I’ll detail the procedure on another post. So , the coil are OK

Now , I’ve ask myself, how does the ECU know when to trigger fire. There are no Distributor cap in this car , so the fire timing is coming directly from the ECU. Correct me if I’m wrong but the ECU know when to fire according to the Cam-Shaft position sensor. This sensor as 3 pins :12v , ground and sensor out on a orange wire going back to the ECU on C22-2. I stripped this wire on the ECU side , and probe it whit a Oscilloscope an there was a nice 0-5v square wave as the motor try to move. So the Crank-Shaft position sensor is working fine.

Is my ECU dead ? Since my P0172 error code , I never got any new error code

[Johnny Mullet]

There is no distributor on the 1998 and newer 4 cylinder engines. The ignition system is controlled by the PCM (ECU) using data from the CMP (Camshaft position sensor) and the CKP (Crankshaft position sensor).

The CMP is located on the driver's side of the head and the CKP is directly below the crank pulley. I would start there.

[energy0uth]

any update on this?

[Tijeff]

Originally Posted by energy0uth

any update on this?

I've check the crank-shaft position sensor to , it was good

I've remove the ECU in order to get a replacement, and noticed it smell burn. I've open it ( I was sure it was gooped in thick stuff but it was not) and noticed it as a big burned spot. Two 1watt 100ohm resistor seem to have cause this damage, and flowing copper traces on the pcb they seem to lead to the 2 coils.
So , my coils were probably not that good.

I was not able to find a perfect fit for replacement coils ( always different shapes and pin-out) And changing the coil and the ECU was not necessary going to work. I was tired of doing mechanics on this car. I bout a 2004 Toyota echo and scraped this one.( long-term parking was also an issue, so I was In a rush)

I have some stuff for sale from this car

All the 4 lights
Brakes parts
Relay
Ext
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4 tire on rims
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