Fuel Injection

[GlasgowRob 0]

ok guys injectors removed from head, crank the car over the injectors dont do there thang, no fuel no spray etc, but got a spark which is fine. BUT when you stop cranking you get the slightest spit of fuel out the injectors (only a tiny wee bit though)

 

 

any thoughts on what would cause the injectors to stop injecting like this????

 

tis a 96 le jetronic malarky 205 :D

 

help guys its driving me nuts

[Ahl 4]

TACHYMETRIC RELAY / ECU!

 

Have you located, removed and taken the plastic lid off your tachymetric relay? Clean the contacts on the relay. If one of the solder joints looks loose/burnt/overheated then resolder it.

Edited June 14, 2006 by Ahl

[GlasgowRob 0]

TACHYMETRIC RELAY / ECU!

 

Have you located, removed and taken the plastic lid off your tachymetric relay? Clean the contacts on the relay. If one of the solder joints looks loose/burnt/overheated then resolder it.

 

 

now the tachymetric relay is the one in the black box behind the headlight sort of under the battery yes????

[GlasgowRob 0]

now the tachymetric relay is the one in the black box behind the headlight sort of under the battery yes????

 

 

 

btw my injectors are green would this make any difference to it?

and what does the green identify it as ?

[pug_ham 242 3 Cars]

now the tachymetric relay is the one in the black box behind the headlight sort of under the battery yes????

That depends, what year is your car?

 

Early phase 1's were by the battery tray but later ones inside with the ecu.

btw my injectors are green would this make any difference to it?

and what does the green identify it as ?

Green or off blue?

 

Greeny blue means they are 1.6 injectors. Most certain way is to get the part number off them though & then you can search for what they are.

 

Graham.

[Rob_the_Sparky 9]

but no the coulur will make no difference wrt making them fire or not (will only have an impact when engine is running).

 

Do you know whether there is pressure in the fuel rail? Is the fuel pump running?

 

Could also be a duff ECU but go with the tachy relay first.

 

Rob

[Craigb 2]

Also a duff coolant temp sensor ( blue one on the back of the thermostat housing ) or wire will knock the injectors off

[Rob_the_Sparky 9]

No it won't. If ECU temp sensor connection is bust it sees an open circuit which is interpreted as VERY cold and increases the injector on time.

[GlasgowRob 0]

Also a duff coolant temp sensor ( blue one on the back of the thermostat housing ) or wire will knock the injectors off

 

 

 

anyone confirm this?

[jackherer 543]

anyone confirm this?

 

as Rob says, a disconnected temp sensor will cause massive overfuelling (as would be needed at -40c or whatever) as opposed to no fuel at all

[brianthemagical 1]

dissconected temp sensor will make the engine very hard to start, if at all.

[jackherer 543]

dissconected temp sensor will make the engine very hard to start, if at all.

 

thats right, but it wont cause the injectors to not open AT ALL as the poster of this thread has said his do.

[GlasgowRob 0]

thats right, but it wont cause the injectors to not open AT ALL as the poster of this thread has said his do.

 

 

anything else to consider before my tachymetric relay arrives monday?

[Pug_101 0]

anything else to consider before my tachymetric relay arrives monday?

 

 

Run a wire from a +12 Volt sorce to the terminal on the tachymetric relay for the injectors and then try again.

The injectors are fired by a switch in the ECU on the earth side therefore they will not fire unless you try to start the engine. I read somewhere on this forum (possibly from Rob the Sparky) that the injectors are 12V, but you might want to check that out first.

Only other thing I can think of thats not been mentioned is the trigger for the ecu to know the engines turing over, not sure of your setup mines got a flywheel sensor that if faulty would stop the injectors firing as the ecu would think the engines not turning over. The fact you've got spark puts this in doubt though.

Cheers

[GlasgowRob 0]

just know its going to be some simple stupid thing causing it lol

 

 

anyone have an ecu pinout and what voltages i should be seeing on these ?

[Pug_101 0]

just know its going to be some simple stupid thing causing it lol

anyone have an ecu pinout and what voltages i should be seeing on these ?

 

You do not have a full ECU for Jetronic i think just seperate systems??

Looking at the Haynes electrical diagrams the power is Pin 9 (which is the centre pin) and the return trigger is pin 12 which is next to it on the "fuel injection ECU"

 

I have taken this from Dia 1b page 368 of the owners workshop manual. The titel of the diagram is:

"Typical engine management, warning lamps and gauges (XU5J/Ja and XU9JA engine models"

Hope this is the right one for your engine.

 

Let me know if you need it scanned.

 

Cheers

[Rob_the_Sparky 9]

The pick-up for engine speed is in the distributer. This goes to the ignition amp which fires the sparks and feed the signal to the ECU and tachy.

 

If you have sparks then you can be pretty sure the amp and dizzy part of the circuit are OK.

 

The injectors have a constant 12V feed and are switched to earth by the ECU. I think the 12V feed comes from teh tachy but would have to check it to be sure.

 

Rob

 

P.S. However, you seem to be assuming that the fuel pressure is OK - have you confirmed this?

[Craigb 2]

thats right, but it wont cause the injectors to not open AT ALL as the poster of this thread has said his do.

 

Sorry guys ,but that is exactly what happened to mine . I had a break in the cable to the blue connector, and it shut down the injectors.

 

This was all checked with a noid tester etc...

 

 

See thread below

 

http://forum.205gtidrivers.com/index.php?showtopic=49156&hl=

Edited June 19, 2006 by Craigb

[GlasgowRob 0]

Sorry guys ,but that is exactly what happened to mine . I had a break in the cable to the blue connector, and it shut down the injectors.

 

This was all checked with a noid tester etc...

See thread below

 

http://forum.205gtidrivers.com/index.php?showtopic=49156&hl=

 

 

well got a shiney new set of injectors hopefully arriving today along with a new tachymetric relay

 

so i'll bung those in then look at the wiring on the temp plug

 

cheers guys

[Rob_the_Sparky 9]

Sorry guys ,but that is exactly what happened to mine . I had a break in the cable to the blue connector, and it shut down the injectors.

 

This was all checked with a noid tester etc...

See thread below

 

http://forum.205gtidrivers.com/index.php?showtopic=49156&hl=

 

And as you said in your thread:

 

"Andy at AB siad straight away , if you have fuel and a spark , its the blue connector on the water temp sensor ".

 

The point is that you had fuel (too much) and spark but it wasn't firing whereas here we have spark but no fuel.

 

Rob

[Craigb 2]

That should have read fuel at the fuel rail .

 

 

The injectors were not firing !

[Guest clarky205]

Had a similar problem after an engine swap on the rally car, check that the wires to the top of the coil are in the correct position!!! Mine were not and i had no fuel except a small squirt when you turn the ignition off but still had a spark.

Mines a 1.6 E reg BTW, there is a wire on the coil that sends a signal back to the ECU when it senses the engine turning to allow the ECU to send fuel.