Thanks Doug..

I'm also going to check the voltages on a number of the terminals of the AFM, i have them down as:-

Pin 6 - 0V
Pin-7 - 2.25V - Flap fully closed
Pin 7 - 7.5v - Flap fully open
Pin 8 - 7.6v
Pin 9 - 12V

Also smooth transition on pin 7 whilst the flap is being moved.

Wil report back with my findings

 

Hey Russell . . . I sense your frustration . . . and share it! With no intention to offend, it has taken us from my post #19, where I pointed out the likelihood that perhaps ALL of your injectors were u/s because of non-use, to your throw-away comment in post #39, as quoted above.

I have no insight about AFM, but see no feedback you have bench tested ALL injectors, nor that ANY of injectors are clicking! I suggest you focus on one issue at a time . . . and resolve it before moving to the next.

Start with a detailed plan -

• firstly, fuel - your test of fuel rail pressure suggests tank, pump and filter are all OK . . . but does this rail pressure sag after (say) 10seconds of cranking? . . . and get assistant to confirm if pump is still pumping;
• secondly, still fuel - ensure a full set of "tested and known working" injectors . . . or alternatively, forget about starting the car until you resolve other issues . . . if 1 is stuck shut, more could be failing;
• thirdly, EFI /ECU - with tested and proven injectors now fitted, verify ALL injectors are "clicking" as engine cranks . . . using a stethoscope if necessary;
• fourthly, spark & timing - as this issue relates to a rebuild non-start, ensure that #1 TDC has rotor pointing at #1 cap post and subsequent HT leads match firing order (anti-cw);
• fifthly, cam timing - again, plenty of rebuilds have seen incorrect cam or diz timing that results in great spark, but at impossible timing;
• sixthly, electrical - check power circuits, fuses, grounds; check also that car has NOT been updated or otherwise fitted with intertia switch, or anti-theft device, either of which if triggered will prevent an engine start;
• finally, AFM / NOID light issue, if relevant or necessary.

I know it's hard when being hit with advice from several quarters and I'm not saying this is the ONLY plan. As Doug knows more nuances about these Jaguar models, I bow to his specific knowledge . . . but the above sequence seems effective in "proving" one critical issue at a time.

Best wishes,

Ken

 

Whew:


A major tutorial on I6 ills diagnostics.


1. Paul Novak posted his travails on J-L with his wife's V12. The fix of the no start
came down to serviced injectors that sat on the shelf too long. Much guessing as to why? But, confirmed shelf life of "serviced" ones is finite.


2. OTH, "used" injectors seem to survive on the shelf much better??? The ones on my LT! were in situ for yeare before I "finished" the conversion and got it to fire up. It seemed that one or two of it's 8, came on a ta time....


3. I've been told and read that lazy" injectors will respond to gentle percussion at times. Key on to get volts, crank and tap to get sequence, tap each as the engine turns or sputters.


4. I was gazing at my Jeep's I6 seeking a means of getting about 3/4 of a tank of fuel out so as to swap in anew in the tank fuel pump. I noticed it has what appears to be an AAV. Solenoid operated, so, it might get a signal from it's PCM to open and close ??? I get the idea that it's FI is Bosch Jetronic very similar....


CArl

 

Ken

No offense taken..

- Fuel rail pressure is good at 36PSI with no sagging at all
- 5 of the 6 injectors click quite nicely, 1 stuck fast without wanting to unstick with various methods.
- In terms of having the injectors click when cranking is a no due to the current problem of trying to find why the AFM being plugged in causes the noid light to barely flicker BUT there is still 11.3 volts on the hot side of the injector when cranking so it's interfering with the grounding circuit within the ECU
- Ignition timing i have looked at multiple times and feel completely confident it is set within a degree or 2 of the required setting, the leads are on the cap correctly and the rotor arm is pointing to #1 lead at TDC
- Cam timing, when the engine was still on the bench i set the cams per the book and rotated the engine by hand many many times to have repeatability that each cam would come back to rest at TDC in their correct position by using the cam alignment tool and checking to see that the crankshaft was pointing at TDC.
- Electrical issues, i'm not sure if my current issues is down to wiring or a component issue, this is something i need to work through, however there is no way to check an ECU for instances without having another to put in its place, more last resort than anything else.

 

Further progress today:-

Early this morning i checked the AFM for voltages as noted on the AJ6 Engineering website and they were all lower than stated which was down to a lower than preferred battery voltage, they were:-

Pin 6 - 0.03V
Pin 7 - 2.12V Fully Closed
Pin 7 - 6.5V Fully Open
Pin 8 - 6.6V
Pin 9 - 10.25 (Supposed to be 2V less than nominal)

There was smooth transition of voltage on pin 7 when moving the flap, i can also hear the fuel pump relay click as i push the flap off its seat.

Based on the low battery voltage the battery has been on charge and this afternoon i went through a couple of checks with regards to the voltages on the injection harness, the power resistor side were all good @ 12.61V, however the ground switching side which are supposed to be the same with the IGN on were ranging from 0V to 0.5V. I have in the past conducted this check and the results were not like this, 12V+ on all terminals of the harness at that time.

My initial thought when i checked the first plug was that the cylinder was due to fire so it was grounding that one to produce fuel, however it should not ground all six at one.

My thoughts are turning to a bad ECU

 

This isn't a sequential system. The ECU 'batch fires' all six injectors simultaneously, twice per engine cycle


Could well be. Fortunately, good used ECUs for these cars are easy to find and not expensive. they actually don't fail all that often so the odds of getting a good one are in your favor

Cheers
DD

 

[QUOTE=Doug;1667404]This isn't a sequential system. The ECU 'batch fires' all six injectors simultaneously, twice per engine cycle

Thats reassuring to know..


Could well be. Fortunately, good used ECUs for these cars are easy to find and not expensive. they actually don't fail all that often so the odds of getting a good one are in your favor

I have sent an e-mail to David Boger as he lists one on his site. The fact that the AFM seems in good shape in terms of the voltages leads me to believe the ECU is at fault and disconnecting a seemingly good component makes it react in an odd way,.

Russell

 

Russell, thanks for your feedback to all of my questions, from which and together with your previous work in checking the EFI grounds, I agree that the finger is now pointing squarely at ECU.

Best wishes with that replacement,

Ken

 

Ken

My mistake was that i had not typed out EVERYTHING i had done to date in one place so apologies for that...

I have an ECU on order from David at Everyday XJ and should hope to see it later this week if all goes well.

Will advise if the transplant takes or not...

 

Hey Russell . . . we have all been guilty of that . . . sorting through facts to present only what we think is relevant. Can make analysis tricky. I have an even more difficult problem . . . trying to cover all bases to aid understanding among a wide range of experience among readers, often leads to verbosity. Gotta keep it briefa . . . LOL,

Best wishes,

Ken

 

Full of anticipation today as the replacement ECU arrived, it was duly plugged in and the Noid light attached and................

It's not the ECU

Same old same old, low light with AFM attached, much brighter with it disconnected.

Is there anyone out there that has a set of Noid lights where they can perform the same test as i am with and without the AFM connected to see if indeed there is a difference in the brightness of the light..

Cover placed back over car, not dealing with it again for a while...

Very very dis-heartened

 

Hello Again

After what seems like months of searching and trying different things i have managed to find something that allows me to start the car BUT with it's own problems...

In a post on this thread some time ago Doug mentioned removing the coolant sensor plug and jumping the 2 connections on the harness, i did try this without any difference, however today i managed to leave this connector off without a jumper and the car started and ran but with ever increasing RPM to the point i have to shut it down. Adjustment of the idle screw on the block underneath the AFM made no difference to the RPM...

To me this seems to be telling the ECU to send more and more fuel to the injectors and i'm sure if i left it alone it would probably cut out due to over-fueling.

Could this be a simple case of just replacing the coolant sensor?????

 

Disconnecting the CTS will cause the ECU to wayyyyy over-fuel...to the point where the engine will instantly die and not restart until the sensor in plugged in again.

The fact that your engine not only runs with it disconnected but actually increases RPM strongly suggests, IMO, that you have a big air leak...big enough to offset the extra fueling.

Cheers
DD

 

Doug

No air leak that can be detected, however of course there ism the air pump on the emissions side of the fence that is pumping plenty of air into the air rail feeding into each of the cylinders. I am assuming this air pump should not run the whole time..

 

Well, not exactly. The air injected into the exhaust ports, not the cylinders. As such, no influence on the fuel mixture, driveability, etc.



The pump runs at all times BUT there's a valve on the back of the pump, the diverter valve, that opens to divert the air into the air filter canister when the engine begins to warm up. The diverter valve 'diverts' when signaled by the coolant temp switch at the rear of the water rail and the 'air switching module' on the RH inner fender. This happens when coolant reaches about 150ºF as I recall.

The engine wouldn't increase speed without additional air coming in from....somewhere. I can't remember where we've been already but have you checked that the throttle blade gap is .002"? No leaks from the hoses to/from the AAV? Ducting from the air flow meter to the throttle body is tight and leak-free?

Cheers
DD

 

Doug

Thank you for confirming on the Air Pump

Blade gap is set to .002". I will systematically look at all of the hoses on the intake manifold to see what might be happening. Also i will look into testing the AAV as that could definitely be the cause if it's stuck in the open position.

Thanks Doug

Russell

 

Hello All

I thought i would post an update on the problems i was having with my freshly rebuilt 4.2 and also let you know the car is now running very well with about 700 miles now covered so the break-in period is almost over.

So the question i have to now answer is what on earth was going on??? So here goes...

As i might have mentioned initially when the engine came out one of the first things i tackled was the inlet manifold which required cleaning, repainting and also servicing of the injectors, all this was done and everything (so i thought) was re-assembled and set aside for installation once the engine went back in.

Due to the fact that it had been a number of months i regretfully did not turn the inlet manifold over before reinstallation to check to see if i had installed the "large" hose that goes from the back of the Aux Air Valve and terminates to the intake...

One of the last posts someone made was commenting on the fact that i must have a huge air leak somewhere for the engine to behave in the way i was witnessing, i also read a post on another forum where someone mentioned an often forgotten hose that is left off which in no way can be seen once the intake has been installed, so hand under intake i felt the little stub of where the pipe needed to be fitted.

In all totally my fault and once the hose was fitted the car ran beautifully and continues to.

I would like to thank everyone that posted to my thread and wanted to "own up" to my mistake in the hope that someone will read this and not let it happen to them...