Starting Problems - Fuel Injectors

[elhsupra]

I have a problem that has been ongoing.
http://lextreme.com/forums/showthread.php?p=21746&posted=1#post21746
My only conclusion is the ECU is not "telling" the injectors to spray. Any help would be greatly appreciated.

 

[Lextreme II]

Did u check if fuel coming out from the injectors? Loose the fuel rail slightly and when you ignite the engine fuel should rush out. If not, take the injector out and manually test it. If they are good, the somewhere along the control system is not working properly.

 

[elhsupra]

Thanks for the input, will try. I did try grounding the injector at the #10, #20, #30, and #40 @ the ECU. The Injector drivers are a voltage-controlled type. When I bypass the ECU and ground the Injectors, they opened because the residual fuel pressure in the rail would drop. This leads me to believe the injector drivers in the ECU are bad or I have a bad input into the ECU that allows the ECU to trigger the injector driver. Based on the lextreme tech articles and this article:
http://www.autoshop101.com/forms/h22.pdf
I am going to try checking my G and Ne signals to insure rpm is being detected for the ECU. Based on Peewee's PM a few weeks ago and Lextreme's comments, I do plan on checking the flow and spray pattern of the injectors and probably send the out to be cleaned. Any other input would be greatly appreciated.

 

[Muzza_NZ]

Hi elhsupra.
Get a decent scope to check the signals from the crank & cam sensors. Also check your injectors with a scope, as you might see a small drop in voltage across them when you start, but not enough from the ecu to actually make them open. Also check you earthing of the ecu body.

It is also possible that you've got a dry joint in the ecu itself, especially if the ecu was sitting for a long time exposed to an uncontrolled atmosphere. To diagnose get yourself a hot air gun or wife's hair dryer and some 'freeze spray' and hit the ecu board around the output transistors - its a long shot but worth a crack.

Have you got any error codes from the ecu?

Muzz

 

[elhsupra]

I found it!!!!!!
It was a bad IgF signal from one of the igniters. The ECU uses the G, Ne and IgF's to trigger the injectors. Even though both igniter are the same Toyota part numbers, they are different Nippondenso part numbers(201 and PHD1) The 201 is the correct one. So off to post in the wanted section. Again, thank you all for your help

 

[sideshow]

i have had a 1uz where it had a bad earth on the ecu which is for the injectors

when crankin the starter motor drained so much current the injectors would not fire

on ecu far left hand side of plugs

there is 2 wires

white with black trace

make sure they good earth

the earth is on back of motor near heads so its a pain of a spot

u need to check if u are getting power to injectors when cranking

then also a pulse to injectors when cranking