1.9Gti Wont Start. Injectors Not Firing Help!

[rob_furious 0]

hi guys im having some problems at the moment with my 205. ill paint you the picture.

 

car ran spot on, parked it up for a week. come to start it and it just wangs over. doesnt even cough! so thought hmm removed the plugs to find they are bone dry. so thought ah fuel pump relay. but that works. so tried bridging the connectors anyway. still no fuel getting to the cylinders. so thought hmm fuel filter blocked. opened the fuel line and bridged the pump. great flow of petrol through the pump. drained the tank. and put some fresh fuel in as it was a bit manky. still nothing. so i took the rail off and aimed the injectors away from the car. cranked it and no spray. so injectors arent working. iv even tried a spare ECU and it had no effect.

 

HELP! what would cause the injectors not to fire!

[Anthony 1,003]

Does it have a spark? If not, you won't get injection either.

[welshpug 1,657]

no spark signal would mean no injector pulse, so check the connections to the coil and ignition amplifier and the lead to the distributor.

[rob_furious 0]

if it sparks what next? im not at the car atm. its at my unit so i want a few things to try so other ideas if it does have a spark.

[welshpug 1,657]

if there is spark you need to ensure that the signal is getting to the ecu, also check that there is an ignition switched 12v+ at the injectors.

[hothatch 2]

I would check the earth supply to the ecu and also as welshpug said check supply voltage at the injectors, make sure its cranking when you check though.

[Pugs in Pieces 0]

did this get solved?

[pyrrhic 14 2 Cars]

Same problem as mine, no solution yet...

[Ballyafb 6]

hi guys im having some problems at the moment with my 205. ill paint you the picture.

 

car ran spot on, parked it up for a week. come to start it and it just wangs over. doesnt even cough! so thought hmm removed the plugs to find they are bone dry. so thought ah fuel pump relay. but that works. so tried bridging the connectors anyway. still no fuel getting to the cylinders. so thought hmm fuel filter blocked. opened the fuel line and bridged the pump. great flow of petrol through the pump. drained the tank. and put some fresh fuel in as it was a bit manky. still nothing. so i took the rail off and aimed the injectors away from the car. cranked it and no spray. so injectors arent working. iv even tried a spare ECU and it had no effect.

 

HELP! what would cause the injectors not to fire!

 

Hi, did you solve this in the end? ( I know it was a while ago now).

I have the same issue.

I have a spark

I have power at the injectors when cranking

the injectors are brand new and have run before

There is loads of fuel in the rail

 

Spark + air + fuel = nothing....

[Telf 224 2 Cars]

This has got to be a broken wire, the signal to your injectors telling them to open can't be getting there.

 

Look at the wiring diagram for your injectors/engine management, there is a common signal line and a common earth.

 

This area when you look at the wiring (on the car)is a mess of soldered/spliced cables, yours may be broken.

 

If you read how the injection system works its fairly well explained. Start checking all the relevant wiring

[Telf 224 2 Cars]

The dizzy supplies a signal at every stroke for the sparkplugs but also to the ECU to initiate the injectors as the spark occurs- at least that's my understanding. So although you have a spark you may have a broken wire to the ECU- or a pin pushed back in the plug.

 

The ECU then supplies a signal to the Injectors - all on a common wire until it splits at each injector - again 1 wire broken or poor contact equals no signal.

 

This would account for your spark, air ,fuel no start.

 

Also don't forget there is a common return line from the injectors. So even if you are testing at the injector for a signal a multimeter may register a voltage but under normal operation nothing will happen (ie your meter is effectively providing the return whilst on test)

Edited May 21, 2016 by Telf

[Ballyafb 6]

The dizzy supplies a signal at every stroke for the sparkplugs but also to the ECU to initiate the injectors as the spark occurs- at least that's my understanding. So although you have a spark you may have a broken wire to the ECU- or a pin pushed back in the plug.

 

The ECU then supplies a signal to the Injectors - all on a common wire until it splits at each injector - again 1 wire broken or poor contact equals no signal.

 

This would account for your spark, air ,fuel no start.

 

Also don't forget there is a common return line from the injectors. So even if you are testing at the injector for a signal a multimeter may register a voltage but under normal operation nothing will happen (ie your meter is effectively providing the return whilst on test)

 

Some good points to check, thanks.

 

I am trying a new pressure regulator as that has been highlighted as a potential. The injectors are getting their signal but if there is not enough pressure to open them then no fuel comes out. Worth a try anyway.

 

It is more annoying that it ran a few weeks ago and has only sat there since, I have not fiddled with any engine bay wiring other than to fit the alternator

[DamirGTI 342]

Tried with easy start spray ? if you run it for a few seconds on spray , or better still , if it starts and runs afterwards without the need for spray maybe it'll ' clear itself ' when the engine heats up-cools down (could be moisture issue or something simple as that)

 

Anyways , easy start spray can be pretty handy diagnostic aid (not precise , but handy) :

 

If it starts on a spray and runs for a second and die , then there is a spark but lacks fuel .

If it doesn't start , not even a cough , then theres a spark problem (no spark , weak spark , fouled plugs , leads/dizzy cap/rotor , coil , ignition amp. , dizzy pick up coil etc.)

 

Also , if it was left for quite a while without starting/driving , try to add some fresh fuel (todays unleaded fuel is crap by comparison what it used to be !)

 

D

 

If you suspect low pressure issue , pinch the return fuel hose with pliers (self locking if you have ..) and then try to start it . By pinching the return hose you'll create high pressure in the rail , certainly above 3.5 bar if the fuel pump is sound .

Edited May 23, 2016 by DamirGTI

[Ballyafb 6]

Changed the fuel pressure regulator and still nothing.

Made the effort to go out and buy easy start.

Big spray, crank, nothing!

 

MASSIVE SPRAY, BANG!

 

Kicked it into life again, so guess all my new parts were in vain and it just had some crud to burn off

 

Thanks for all the help

[Telf 224 2 Cars]

Case closed !