I gtried three things today. based on "So Ya got a HE V12 that won't start". First I replaced the Coolant Temp Sensor with a spare. I compared resistance readings between the two pins. The one in the car read .002 ohms. The replacement read .004 ohms.

Connector with blue heat shrink plugged onto the Coolant Temp Sensor

Next I plugged a spare throttle turntable and TPS


Spare Throttle Position Sensor plugged in and tywrapped to full open


I also placed a spare Power Resistor and used a aligator clip jumper to ground the case..


spare power resistor connector

I tried starting the car after each installation to see if injectors clicked. No injectors. I did, however have ignition spark.

Any thoughts?

 

As long as the spark is fat and strong, then the problem is fuel delivery.
So, first question: will the car start on ether?

 

Doug;

I checked pins 16, 17, 34 & 35 and all are showing 0 ohms to ground.

Greg;

It fires on ether starting fluid.

 

So it is fuel delivery for certain then. Take a look at Sanchez's thread, he had exactly the same trouble.

 

Greg; Thanks for the info on Sanchez's post. It took me a while to find it, but I have read and printed it out. Speacial thanks to Graham Francis for the attatchments in Sanchez's thread. A lot of good information there.

I checked the EFI harness for the TPS female connector and the male connector on the TPS lead. I ended up cleaning both with fine sandpaper and contact cleaner.

I did the same for the connectors to the Power Resister and the connector for the Injector Harness.

I used a jumper wire and checked continuity of all wires from the EFI ECU to the Power Resistor and for the injectors.

I verified continuity from the Red & White wire at the Starter Relay to Pin 26 of the ECU and then confirmed voltage to Pin 26 with the Mrs attempting to start the car. I tried the test with the with the ignition on and turning the Throttle turntable to wide open, but did not get any injector clicks.

I also confirmed power to Pin 22 of the ECU with the ignition on while the Mrs attempted to start the car.

Next I will verify the wires for the TPS and the Coolant Temp Sensor and report back.

 

To recap, I get the fuel pump running for two or three seconds when the ignition is on.

I verified the Yellow & Black wire from the TPS to the Coolant Temp Sensor. I verified the Blue & Orange wire from the CTS to Pin 5 of the EFI ECU.

I verified the Yellow & Pink wire from TPS to Pin 20 of the EFI ECU. I verified the Yellow & Black wire from the TPS to Pin 19 of the ECU.

Well I must be missing something, but I do not know what it is.

 

Fuel pump sounds correct. Apart from everything else you are doing, ask Madame to turn the starter and just verify that when the starter is turning that the pump runs. If so, the pump side of things is correct.

 

Yes. Just this! Then report back with a quick confirmation (or a no go) sentence and go from there... You're close. I think, once the fuel pump issue is put to bed, it's a fueling issue at the injectors.

Resist overwhelming yourself looking at tooooo many things. One little step, focusing on individual systems, at a time.

 

Greg & Jay;

Had the mrs. attempt to start the car. With ignition on, I get the two to three second prime. With the starter engaged, fuel pump runs. So, I have fuel, spark, but still not injectors clicking.

 

Good! So the fuel pump runs and you have (still?) Spark?

Have you done any tests on the white co-ax wire that runs from the engine bay to the ECU in the boot?

 

I think, and this is just me, that you are going to need to be paying attention to the info in this diagram...

Are you sure that both the crank position sensor and the fly wheel position sensors are good, that the wires are intact and that there signal wires are well grounded and making it to there respective ECUs?

Also, that grounds are clean and well fastened in the engine bay and back by the battery?

 

Perhaps already discussed but do you have 12v "+" on the pink/black wires to the injectors?

Cheers
DD

 

Jay,

Both sensors are new I had checked/confirmed that the white wire from Pin 24 of the DI ECU connects to Pin 18 of the EFI ECU, but will verify again.

I also checked the wires for the Fuel Interface Unit (Figure 19.1) Yellow and Greenwire that connects to Pin 29 (Pink & Green) of the EFI ECU. The Schematic for the Interface unit does not show what is inside, but the unit does connect to ground.

What I do not get is how the injectors get ground to complete the circuit for the injector solenoids to trigger. All the injectors get power through the Pink and Black wire of the Main Relay.. The other side of the injectors connect to Pins 8, 9, 13, 14, 27 & 28. So, it appears that the ECU completes the injector grounds through Pins 16 & 17.

So, I will check both again.

 

Mike
The ECU grounds the injector circuit, as you surmise. Do you have 12v to the injectors? If so then the grounding circuit is the problem.

 

Yes. The ECU completes the grounds.

Have you made sure, as Doug suggested, that you have 12v to alllllll injectors? All of them?

Grounding at and around the batter for the ECU and other things need to be good.

I don't think there is much need to be messing with the "fuel interface" at the moment.

 

Just FYI the Fuel Interface Unit takes info (injector pulse width) from the ECU and turns it into a language the Trip Computer can understand so as to give the fuel economy readings

Right. The injectors have 12v "+" with the key on and the ECU grounds them. The "Injector On" and "Injector Hold" circuits ground the injectors via Pins 16, 17, 34, and 35.

If you checked the injector wires with the key on they'll all show 12v "+" until the ECU grounds the orange/xxxx wires to operate the injectors

It's kinda sorta maybe beginning to sound like you have a faulty ECU.

Cheers
DD

 

All;

I verified that all 12 injectors have 12 vdc.I did not cut open the injector harness to confirm the color of the wires. I paid several hundred dollars for the current harness and used it prior to the engine rebuild with no problems.

I also considered a faulty ECU, and swapped with a used one recently purchased. Same conditions with either ECU installed. While the Mrs attempts to start the car, I measure 13.25 vdc with the ignition on, dropping to 11.25 vdc with the starter turning over the engine.

I pulled the battery and then cleaned all the ground wires attached with the two bolts using a Scotch-Brite pad followed by spraying contact cleaner.

I pulled the connectors at each injector and verified the 12 volts.

I swapped both ignition sensors and verified that I still have ignition spark.

Still no injectors clicking.

 

Hi Mike

So you've got a Spark and the Fuel Pump runs but the Injectors don't 'Click'

My own guess for what its worth or not as the case may be, is that although your Fuel Pump runs, its not retaining the Fuel Pressure of 30psi (2 BAR) Approx

Which 'Could' mean that the Non Return Valve in the Fuel Pump is leaking, so that the Fuel Rail is unable to retain the amount of Fuel Pressure required

In which case it could well be worth trying an 'el cheapo' unbranded Fuel Pump about $30 on ebay to see if that makes any difference and if not then you could keep it in the Boot/Trunk as a Spare in case you need to use it for a roadside repair, as changing over the Fuel Pump at the side of the road is very easy 'in the scheme of things'

So I for one have re-positioned my Fuel Pump (easy job no plumbing required) to keep it in plain sight, just in case I ever need to do this and I always use the 'el cheapo' pumps, instead of the expensive OEM Brands as they are generic and fitted to loads of different Cars

Another possibility is that your fuel pump could be running backwards! and I have actually had that happen and had to swap the + and - around (not uncommon) on unbranded Pumps depending on where it was made, though once I had swapped the Connections around, it never let me down

Also it could be Water in the Petrol which is why in the UK there is such a Ferore about using E10 Petrol which Classic Car owners in the UK seem to be avoiding like the Plague, where I've heard that Water in the Petrol can cause a Foam which can very quickly Gum up your Injectors

Alex

 

Mike, try disconnecting the connector to one of the injectors, and apply 12v momentarily directly to the injector. If it clicks, good. If not, it's stuck. I've heard of all injectors sticking on engines that have been sitting for awhile. Apply 12v momentarily several times to a stuck injector until it frees up. Go true each injector until they all click. Don't leave 12v powering injectors continuously, just momentary pulses.

 

Brother... You have done a LOT of work, and digging, and measuring and and and, and when you figure out what the SMALL thing that you "missed",,,, I need you to promise me that you're not going to punch yourself (or someone else) in the face...lol
There is something simple preventing those injectors from firing.

At some point in this thread (I haven't gone back to read it all) you said that you DID have clicking/firing injectors, yes? And, before the major work, the injectors were firing, yes?

Just because those 2 (KEY) sensors are new doesn't mean everything with them is right.

I don't believe the ECU is getting the signal it needs to fire them injectors. I think it's as simple as that. The couple of bits that are involved in that (yes, including the ground points) are the only things I would be focusing on.