Okay my '89 Si hatback won't start up. It turns over, spark on all 4 cylinders, but it won't start. This was a problem that occured every once in a while but it would start after waiting a few minutes or a day. Well it's been stuck now for 4 or 5 days, still cranking but won't fire up.

I need to know what exactly the problem is. Someone before said a bad relay. Anyways, it's at work so I don't have all my tools, but do have access to a multimeter.
I'm pretty sure it's an electric problem, but I don't know where to look.

Voltage on fuel pump was ~6-7V. Doesn't it run on 12V? Is it the harness right under the front edge of middle of the backseat?

Where is the ECU located? I can't see it, is it under the large plate in the passenger footwell? What fuse is the ECU on?(Not the backup power).

TIA

 

okay... it sounds like timing... if your geting fuel and spark... check your cam timing..

 

I don't know if I'm getting fuel. When it runs it runs fine so I don't think it's the timing, remember this problem usually goes away, which is why I think it's electrical. I dont' think it's the timing because it doesn't even sputter. Cam timing? No reason for that to be off.

The car is my beater it has 210k miles. It's stock.

 

check the ecu.its probly an injector being stupid.see if you getting any codes and go from there.

 

Um, I can't exactly check for codes if the motor is not running now can I?

Where is the ECU located?

 

ok,on the passenger side fire wall pull up the carpet on the is a big gold plate.in the middle there is a hole .there is a led light that flashes if there is a code.start the car and see if it flashes a code,it will blink.count how many flashes it will flash.them tell me or us.

 

Sounds like it could be the main relay, I dont now how to check it or anything, but the simptoms sound about right.

 

Ok, thanks, I wasn't sure if it was under there or not. Now does anyone know what fuse the main ECU power is on?

 

from your pos battery post follow the wire to the fuse box.open and thats where it its at.is the metal broke?did you get a code?

 

From experience, i assume alternator solenoid fuse, runs the power to the ecu. if that fuse gets burnt, the ecu will not throw any codes or should i say flashes. if your fuse for the alternator solenoid under the steering wheel is ok and your getting flashes...try checking your other fuses. Good luck!

 

check main realy near fuse box inside...
make sure ur inyectors are inyecting.. take a spark plug out. it should be wet and smelling gas.... loosse the gas line to see if u have pressure and it spits gas....
make sure ur car its on time......
check all fuses....
does the check light goes off while cranking ( it should turn off)
check all plugs on engine bay.. soemtimes , a stupid plugs comes off and engine wont start....

 

I believe this is the backup fuse, not the main fuse... it's always on. The main fuse should be on only when ignition is on, I think.

Does the ecu throw codes without the engine running? My experience says no. So if this is the case, please stop telling me to check codes, because I've made it pretty clear the car does not start.

 

yes, it will throw a code not running!!!!!! forgot that it did not start,sorry!

 

to reset ecu pull the hazard fuse

 

Thanks.

Now can someone tell me the voltage the fuel pump runs on? I'm still wondering why there is no 12V signal at the pump harness... only ~6V

 

The fuel pump runs on 12 volts. The main relay contacts close and pass the 12 volts to the pump. Either you've got poor contacts in the main relay or bad wiring to the pump or ground. (BTW... the typical failure mode of the main relay is no power to the fuel pump or no power to the injectors. The cause is hairline cracks in the solder joints that open with thermal expansion. If one of the joints was making poor contact, it could explain your 6v at the pump)

 

Gosh your suggestion fits eerily in with some evidence I've witheld. It did seem to be teperature realted, becoming worse over time. Also it once worked right after I kicked my dashboard

I will check the PCB for cracked solder, hopefully that is the problem.

THanks

 

If you have 6-7 volts at your fuel pump I would definitely try the main relay- it simply toggles battery voltage on and off to the fuel pump at the command of the ECU. If you want -while cranking try smacking the side of the dash by the driver's door (with the door open)FIRMLY- this sometimes knocks the relay contacts into submission.

 

Lol, kicking doesn't work anymore, believe me I kicked the **** out of my dash