No injector pulse - why?

**demuire** · 06-06-2006, 01:14 PM

I have an SV21 Camry, and it won't start. I drove it into a carpark, went away, came back, and it won't start anymore... Have checked:

Battery OK - well, getting rather low now, but was OK.
Starter motor OK
Fuel pump OK
Fuses OK
Dizzy OK
ECU replaced, no effect
TPS OK
Spark plugs OK
Cold start injector OK
Injectors getting power, but NO PULSE.

ECU reads error code 51.

RACQ man gave up.

Any ideas?

**Hydra** · 06-06-2006, 01:16 PM

Got a multimeter with duty cycle? That might help in finding the problem.

Since you've had the ECU out.. just check to see if there is pulse at the ECU (should be able to stick a multimeter probe into the plug far enough to check).

**TRAV-KE55** · 06-06-2006, 01:19 PM

hall pick up in dizzy?

**wilbo666** · 06-06-2006, 01:21 PM

http://www.personal.psu.edu/rae125/checkeng.html

http://www.off-road.com/toyota/tech/codes/

Is it auto? It maybe the NSW...

If it is the NSW then I would not expect it to crank...and hence not start. If is the dizzy (no NE signal) then I would it expect it to crank but not start...

Cheers
Wilbo

**slide86** · 06-06-2006, 01:31 PM

ground points?
dont injectors need a ground also to fire. perhaps a ground wire has come loose, you would still get power at the injector. but with no ground there wont be a pulse......

**wilbo666** · 06-06-2006, 02:08 PM

Originally Posted by slide86

ground points?
dont injectors need a ground also to fire. perhaps a ground wire has come loose, you would still get power at the injector. but with no ground there wont be a pulse......

The injectors are GND'd via the ECU...it could be the wires to the ECU, or the ECU gnds, or the transistors in the ECU...but all of those are quite unliekly to kill pulses to the 2 circuits (batched injecton) (would be two of each failing +)...

Cheers
Wilbo

**demuire** · 06-06-2006, 03:11 PM

Thanks for the replies.

Tried putting in a bit of Start Ya Bastard, and strangely enough that didn't do anything either. Which would point to no spark? But take out plugs and they fire?

It's a manual Camry.

Don't know which wires are for injectors, there are a few the same color? Maybe it's the dizzy that's dead... But testing the resistance (as per Gregory's manual) says everything is OK, does this really say the dizzy is OK? Car cranks fine, so fine in fact that my battery is now virtually flat.

**Vios-GT_07** · 07-06-2006, 06:26 AM

oh.. hmm.. RACQ man gave up and u've swapped ECUs..

and atm u've pinpointed the injectors not pulsing ..

try swapping fuel rails and injectors? just a suggestion ...also petrol filter??

hm.. then again.. not pulsing.. try pulling out a fuel line to see if petrol is reaching to the fuel line and injectors? if there's no petrol reaching then there's blockage somewhere.. but petrol is getting there, porbably just swap injectors and see wat happens?

**johnny blade** · 07-06-2006, 07:19 AM

The dizzy seems to be the biggest problem on these engine, try to change it for an other.

**Grega** · 07-06-2006, 07:24 AM

fook, when you say no pulse, do you mean no voltage or are they not spraying fuel at all?
can you check to see if there is power to the injectors at the ECU end?

its been a while since i looked at a toyota wiring diagram but is there like a safety override in the event of no oil pressure or something else ect to stop the car from starting?

do camry's have a circuit opening relay? is there any chance this could be giving you grief?

**demuire** · 07-06-2006, 08:35 AM

Vios: Fuel rail has fuel, fuel pump is running, and cold start injector squirts fuel. The other injectors have voltage, but aren't pulsing.

Grega: Don't know about a safety override. It does have a circuit opening relay, but if this wasn't working the ECU wouldn't get power...

Spoke to a mechanic yesterday (the car was towed to him last night, he'll have a look today), and he thinks it's likely one circuit of the immobiliser has shat itself. Don't know what the immobiliser is currently hooked up to, but he recons it's probably hooked up to either the signal from the dizzy (crank angle sensor? whatever it uses...), or to the injector pulse to the ECU. Apparently the ECU switches ground, injectors having voltage but no pulse would have to mean that the ECU is not switching - either because it's dud, or because it doesn't kwow when to...

Will let you know once we find out what it actually is...

Thanks!

**Grega** · 07-06-2006, 08:48 AM

ah. immobiliser. aftermarket?

**demuire** · 07-06-2006, 10:22 AM

Yes. Aftermarket. The other circuits are working fine, and I didn't think it would be hooked up to something like the injectors...

And well, I'll be damned. Had the car towed out to the workshop yesterday (to get looked at today), mechanic came out this morning to have a look at the car, and it started first go. Checked it over, checked it twice and trice, and it runs fine.

Typical... Just typical...

**Hen** · 07-06-2006, 10:45 AM

That sure is typical.

And you know when it'll pop up again, that's right, when you are 300km out of town and need to get to work for something important.

I had such a problem, very intermittent not starting on cold mornings due to a lack of spark, which was eventually fixed (I think) with a new battery. Hopefully you discover it was something as simple as this.

Hen