CAFROG's K20-R EGg

[CAFROG]

I actually used 4 grounds, one on the back of the trans, one on the front of the trans, one on the back of the head & one on the IM. Make sure the ground from the engine harness (near injectors) makes good contact with the engine. Tech - K-Series Engine Ground

I used a thread chaser bolt to clean the threads of the holes on the chassis really good & a wire brush wheel to clean the threads on the bolts that ground the wires.

The link shows the ground on the valve cover just like I did. But I will add another to the trans and move the ground in the front block to the rear of the block near the timing chain cover and header. I did have two grounds to the same spot on the chassis (one off the back of the IM and one off the front of the block)which I didn't think would be a problem but maybe it is.....

 

[CAFROG]

Does the actual ECU need to be grounded to the car? What I mean is.....I do not have it mounted directly to the chassis. I used some plumber's tape with bolts/nuts and some zip ties. I figure it gets its ground from the harness (ground near injector plugs)

 

[Dual-500]

On the older OBD0 & OBD1 ECU's they do not pull electrical ground from the chassis - it's all through the wiring harness. I explored that troubleshooting mine on the initial start up - it had a loose ground at the thermostat on the engine. The P06 ECU in my hatch is still loose and sitting in the floorboard on the carpet and I'm driving it.

I'd expect the later versions to be the same in terms of a electrically floating metallic chassis.

 

[Dark93DX]

Does the actual ECU need to be grounded to the car? What I mean is.....I do not have it mounted directly to the chassis. I used some plumber's tape with bolts/nuts and some zip ties. I figure it gets its ground from the harness (ground near injector plugs)

No the ECU itself does not need to be grounded, its grounded through the harness. My ECU was sitting on the floorboard carpet as well when I started it up and drove it around.

 

[Dark93DX]

The link shows the ground on the valve cover just like I did. But I will add another to the trans and move the ground in the front block to the rear of the block near the timing chain cover and header. I did have two grounds to the same spot on the chassis (one off the back of the IM and one off the front of the block)which I didn't think would be a problem but maybe it is.....

My transmission grounds (front & back) both ground to the chassis on the driver side frame rail in different spots. My IM ground runs to near where my rad overflow is (passenger side since I moved my rad to the drivers side). The ground off of the back of the head grounds right near where the main battery ground is (passenger side near fuse box)

 

[newb]

In to see the finished product.

 

[GlassHeadlights]

Check into injector wiring. I know Taco is having a rough time with OBDII injectors too.

 

[eg6sir]

its Friday!!.. whats the word homeslice?

 

[newb]

^Werd

 

[CAFROG]

Well......I checked the injectors with plug off. One wire on neg terminal....One wire on pos terminal. put neg end on a injector prong and pos on the other. I got a small "pop" sound which I was told tells me the injectors will open.

I also tested the plug with a light tester. The yellow wire (black stripe) on all the injectors is getting power but the other wire......gave me nothing (when I was cranking it over).

I do not know but was told that one is constant and the other is for when the ECU tells the injector to open up.

So.....to the grounds.....I guess.

 

[Ethan]

Correct me if im wrong but doesn't the injector only get short bleeps of power when cranking? im pretty sure my injectors showed nothing with a light tester i had to use a muti-meter and then it showed jump's.

Just trying to help.. You have spark right? Could it be a ignition issue?

 

[CAFROG]

I got spark when using starter fluid

Just switched my grounds and put one off the block directly to the battery......nothing. put it on the chassis....nothing

 

[CAFROG]

im pretty sure my injectors showed nothing with a light tester i had to use a muti-meter and then it showed jump's.

What setting on the multimeter? Ohm or 12 volts? I know its just a burst but I want to see if there is some type of reading.

 

[Ethan]

i dont remember

 

[Dual-500]

Well......I checked the injectors with plug off. One wire on neg terminal....One wire on pos terminal. put neg end on a injector prong and pos on the other. I got a small "pop" sound which I was told tells me the injectors will open.

I also tested the plug with a light tester. The yellow wire (black stripe) on all the injectors is getting power but the other wire......gave me nothing (when I was cranking it over).

I do not know but was told that one is constant and the other is for when the ECU tells the injector to open up.

So.....to the grounds.....I guess.

The injectors have 12v on one side of them all the time, the ECU pulls the other side to ground to trigger them.

 

[CAFROG]

Good.....that ^^ confirms what I was told.

Guess I'll try a multi-meter on 12v to see if power is sent from the trigger wires.

 

[Dual-500]

Good.....that ^^ confirms what I was told.

Guess I'll try a multi-meter on 12v to see if power is sent from the trigger wires.

Power doesn't get "sent" from the trigger wires. Power is applied to one side of the injectors all the time when ignition energized. The side of the injector coil that is connected to the ECU gets pulled almost to ground to "trigger" the injectors. When the ECU "pulls" one side of the injector coil to ground it completes the circuit which induces current flow through the injector coil which fires the injector to flow fuel.

So, to measure you will see a short duration spike towards ground from 12v on the side of the injector coil that connects to the ECU. Connecting one side of the injector coil to 12v, the other side that goes to the ECU "floats" at 12v until the ECU gets the trigger signal from the crank position sensor, at which time the semiconductor device in the ECU receives a trigger signal to fire and pull the line to the injector almost to ground. It should read around 0.5v when the trigger signal is present - that's a guess, but an educated one.

Someday, I'll take the scope outside and measure it just for grins to know exactly the voltages and duration at idle.

Hope this helps.

To measure this with a meter, you may just see the numbers move around - I doubt a DVM would register anything readable as the pulse duration is probably way to short for the meter to lock on to.

What you need is something like this: http://uniquetruck.com/p-10222-ignition-fuel-injection-pulse-tester.aspx

 

[CAFROG]

So, to measure you will see a short duration spike towards ground from 12v on the side of the injector coil that connects to the ECU. Connecting one side of the injector coil to 12v, the other side that goes to the ECU "floats" at 12v until the ECU gets the trigger signal from the crank position sensor, at which time the semiconductor device in the ECU receives a trigger signal to fire and pull the line to the injector almost to ground. It should read around 0.5v when the trigger signal is present - that's a guess, but an educated one.

So the signal sent to the other wire is more of a ground in which it completes the circuit and opens the injector?

To measure this with a meter, you may just see the numbers move around - I doubt a DVM would register anything readable as the pulse duration is probably way to short for the meter to lock on to.

I just want to know if the injector wires are sending the signal or not. I know I got the 12v constant wires sending power but want to know how to check the other wire on each injector clip. If its a ground.....I may have an idea.

 

[Dual-500]

1) So the signal sent to the other wire is more of a ground in which it completes the circuit and opens the injector?

2) I just want to know if the injector wires are sending the signal or not. I know I got the 12v constant wires sending power but want to know how to check the other wire on each injector clip. If its a ground.....I may have an idea.

1) Yes - it grounds momentarily to "Fire" the injector.

2) I understand you do. Yes it floats and will get a momentary ground pulse. Probably could use a simple LED as a test light in a simple circuit. Connect the LED across the injector or from battery positive to the line from ECU to injector and watch for the LED to blink.

8mm LED Package Type | Component LEDs | Super Bright LEDs

LEDs Magazine - Driving LED lamps

LEDs Magazine -

Here's the page that tells how to size the resistor: LED Information - Super Bright LEDs

You should be able to get this stuff at Radio Shack and the sales people, if they have a clue can assist.

The pulse signal looks like this on a scope: http://www.autonerdz.com/firstlook.htm

It's the negative square wave on the lower red trace. The positive spike is after the ECU released the "Ground" or logic "0" from the line to the injector and is a counter EMF (electro motive force) coming from the injector as the magnetic field collapses and injector closes.

Here's some more good info: http://www.picoauto.com/tutorials/fuel-injection.html

 

[double0Si]

Just a note since I see you are using the RBC manifold, you will have to cut a little bit of the webbing from under the hood just to clear the vacuum line for the brake booster that comes off the manifold, but its no big deal.

You mean like this?

With the RBC IM....clearance is an issue. Some guys plug the brake booster (JB Weld or whateva) and re-install the nipple on the underside of the IM. I decided to bend the brake booster nipple down a little and I also have the Evap Purge (at least until I get K-Pro) so I had to cut my hood regardless.

Here's a pic of the clearance issue

Cut my hood support to clear the brake booster nipple and evap purge.

In terms of making it look great.....I didn't want to do much but I taped off a section and primed the exposed metal and lightly every where else.

I used the paint for the faded engine bay (stuff I got matched in a rattle can) so it doesn't match great but it does the job.

AND the best part is my hood shuts now Not the best job I could have done but for the whole thing taking less than 90 minutes.....its good enough

<THAT guy.