Injectors not getting voltage pulse from ECU.
#26
Full Member
Thread Starter
Join Date: Oct 2010
Location: IE cal
Posts: 69
Likes: 0
Received 0 Likes
on
0 Posts
Satch.... You are the man... That was the piece of information i have been wondering about...
I will test the injectors spray next..
And we will see where that leads me..
I will test the injectors spray next..
And we will see where that leads me..
#27
Full Member
Thread Starter
Join Date: Oct 2010
Location: IE cal
Posts: 69
Likes: 0
Received 0 Likes
on
0 Posts
No worky... Something is stopping the pulse from the ECU.. What could it be..
http://www.youtube.com/watch?v=lMJEOoB4DYs
http://www.youtube.com/watch?v=knqiqbFgRHU
http://www.youtube.com/watch?v=lMJEOoB4DYs
http://www.youtube.com/watch?v=knqiqbFgRHU
#28
Moderator
iTrader: (1)
You can remove the plug to the injector and test for voltage on the wire from the ECU to see if you get the 8 volts when starting. Also, w/the injector plug removed, set the meter to ohms and place one lead on the injector terminal and the other meter lead on the other injector terminal and see if you have low impedance injectors or high impedance injectors. Low would be about two to three ohms while high would be about 11 or twelve ohms. An "86 S4" is supposed to use "low impedance injectors" and this might be your problem.
#29
Full Member
Thread Starter
Join Date: Oct 2010
Location: IE cal
Posts: 69
Likes: 0
Received 0 Likes
on
0 Posts
They injectors are low impedance. They are 3 ohms.. all of this has been checked..
I am thinking that some thing like a part will tell the ECU not to send the signal.. Like my CAS for instance... If it had a bad wire.
I am thinking that some thing like a part will tell the ECU not to send the signal.. Like my CAS for instance... If it had a bad wire.
#30
Moderator
iTrader: (1)
Before I mentioned the impedance of the injectors did you state that this aspect had already been checked and verified? Nope.
#32
Full Member
Thread Starter
Join Date: Oct 2010
Location: IE cal
Posts: 69
Likes: 0
Received 0 Likes
on
0 Posts
All of these thing have been checked...
Resistor Pack/Box = GOOD
injectors = GOOD
volts = GOOD 12v and 8v
The plugs from the Primary injectors can not reach the secondary injectors.. and the secondary injectors would have fired.. They are wire up also..
Here is the thing.. an injector is a coil. I posted a colored schematic... on my profile just in case to help me..
a coil.. is an electro magnet.. it uses positive and negative voltage to work. I should be getting a pulse from the ECU on pins 3E and 3C ... the other side of the voltage...
If i dont get it.. then the injectors will not fire..
So the ECU or somthing attached to it.. .. My guess is something attached to it has a broken wire.. and is telling the ECU not to work..
Or the ECU is crap.. But i have gotten 2 more and how many ECU's do you really go through..
1 ECU came out of a working car..
So what would tell the ECU not to fire the injectors..
Anyone???
Resistor Pack/Box = GOOD
injectors = GOOD
volts = GOOD 12v and 8v
The plugs from the Primary injectors can not reach the secondary injectors.. and the secondary injectors would have fired.. They are wire up also..
Here is the thing.. an injector is a coil. I posted a colored schematic... on my profile just in case to help me..
a coil.. is an electro magnet.. it uses positive and negative voltage to work. I should be getting a pulse from the ECU on pins 3E and 3C ... the other side of the voltage...
If i dont get it.. then the injectors will not fire..
So the ECU or somthing attached to it.. .. My guess is something attached to it has a broken wire.. and is telling the ECU not to work..
Or the ECU is crap.. But i have gotten 2 more and how many ECU's do you really go through..
1 ECU came out of a working car..
So what would tell the ECU not to fire the injectors..
Anyone???
#33
Moderator
iTrader: (1)
All of these thing have been checked...
Resistor Pack/Box = GOOD
injectors = GOOD
volts = GOOD 12v and 8v
The plugs from the Primary injectors can not reach the secondary injectors.. and the secondary injectors would have fired.. They are wire up also..
Here is the thing.. an injector is a coil. I posted a colored schematic... on my profile just in case to help me..
a coil.. is an electro magnet.. it uses positive and negative voltage to work. I should be getting a pulse from the ECU on pins 3E and 3C ... the other side of the voltage...
If i dont get it.. then the injectors will not fire..
So the ECU or somthing attached to it.. .. My guess is something attached to it has a broken wire.. and is telling the ECU not to work..
Or the ECU is crap.. But i have gotten 2 more and how many ECU's do you really go through..
1 ECU came out of a working car..
So what would tell the ECU not to fire the injectors..
Anyone???
Resistor Pack/Box = GOOD
injectors = GOOD
volts = GOOD 12v and 8v
The plugs from the Primary injectors can not reach the secondary injectors.. and the secondary injectors would have fired.. They are wire up also..
Here is the thing.. an injector is a coil. I posted a colored schematic... on my profile just in case to help me..
a coil.. is an electro magnet.. it uses positive and negative voltage to work. I should be getting a pulse from the ECU on pins 3E and 3C ... the other side of the voltage...
If i dont get it.. then the injectors will not fire..
So the ECU or somthing attached to it.. .. My guess is something attached to it has a broken wire.. and is telling the ECU not to work..
Or the ECU is crap.. But i have gotten 2 more and how many ECU's do you really go through..
1 ECU came out of a working car..
So what would tell the ECU not to fire the injectors..
Anyone???
Also, the secondary injectors "only fire under load and this does not occur while the car is free reved in the driveway" unless you trick the car into thinking it were under load, which is done by disconnecting the vacuum hose to the Boost sensor, plugging said hose, and disconnecting the TPS. Doing this creates load.
EDIT: One thing you could do is to depin 3E and 3C and then switch over the wires from the secondary injectors which are pins 3H and 3F to where 3E and 3C go and then turn over the engine and see if the injectors connected up to these two wires will fire, either the secondary injectors connected to these two wires or switch them out for the primary injectors.
#37
Moderator
iTrader: (1)
Perhaps the voltage drop on the ECU injector wires is caused by the electrical drain from attempting to start the car and not because the ECU is sending a ground signal. If this is so, then you should remove the small ECU plug and put a ground to the injector wire w/the key to on to see if the injector spits out some fuel. This is my last advice to you.
#38
Full Member
Thread Starter
Join Date: Oct 2010
Location: IE cal
Posts: 69
Likes: 0
Received 0 Likes
on
0 Posts
So i have tested out my ECU.. Put it in another car.. It runs fine...
Thanks AC chillin.. RX7 guy here in town.. Who let me test it..
He said that i should get a under the hood harness.. Off a wrecked car.. That might not be a bad idea..
i have been tracing wires and voltage here and there.. nothing yet...
So I know now that i have a component or a wire that is messed up... I just have not found it ..lol Thanks every one and most of all Satch for the help...
Thanks AC chillin.. RX7 guy here in town.. Who let me test it..
He said that i should get a under the hood harness.. Off a wrecked car.. That might not be a bad idea..
i have been tracing wires and voltage here and there.. nothing yet...
So I know now that i have a component or a wire that is messed up... I just have not found it ..lol Thanks every one and most of all Satch for the help...
#40
Full Member
Thread Starter
Join Date: Oct 2010
Location: IE cal
Posts: 69
Likes: 0
Received 0 Likes
on
0 Posts
I got the car started.. after a long test everything out.. I am not sure what the full issue was. Boy do I know more about my rotary though..
It seems that i have to floor the gas to get it to start though.. and it will stall until it gets warm.. But after its warm it is working fine..
So if anyone know what this issue is.. thanks for any help.
It seems that i have to floor the gas to get it to start though.. and it will stall until it gets warm.. But after its warm it is working fine..
So if anyone know what this issue is.. thanks for any help.
#42
having same problem tested or seapped everything i know
I have 87 no ground pulse cranks runs off brake kleen grounded green wire to inj and tap and it will run checked cas. swapped resistor pack injectors and have swapped the ecu’s out the only ground i have not checked or cant see is the ecu ground under the intake but i have checked and redone the battery ground and the tower strut bar ground amd also i noticed the previous owner took a few of the
grounds and wired them together right before they go into the ecu i have been fooling with this problem forever and swapped out so many things with no ground pulse blowing my mind
someone please help me before i set this thing on fire
grounds and wired them together right before they go into the ecu i have been fooling with this problem forever and swapped out so many things with no ground pulse blowing my mind
someone please help me before i set this thing on fire
#44
I thought i figured it out and it was the solenoid resistor was reading 7 ohms ordered the only one i could find on ebay used did not work it is blowing my mind
#45
when you spray it it fires right up and if you take the green wires off the ecu and ground them it will fire up the rpm gauge jumps when you turn it over has new injectors and new fuel pump getting 50 lbs of pressure just no ground pulse and the ecu has been swapped out as well
#46
rpm gauge jumps when turning it over wire bypassed the solenoid still no pulse cranks and runs on brake kleen re did ground on tower battery added extra ground on ecu new injectors im stumped please someone help me here i am semi mechanical and have been fooling with this for momths now with no success
Thread
Thread Starter
Forum
Replies
Last Post
HalifaxFD
Canadian Forum
126
05-09-16 07:06 PM
The1Sun
1st Generation Specific (1979-1985)
7
09-18-15 07:13 PM