A miracle....Slowy's cobra update

[Modena]

slowy, I know nothing about this Ford motor, but I will try to lend a hand with generic suggestions!

• timing for the computer is coming from either cam sensor or crank sensor, so if one or both are wrong something won't work. If the cam sensor is "irrelevant" then why is it there? Of course it's not irrelevant, that signal is used by the computer for something
  
• how old is the fuel?
  
• do you have enough fuel pressure?
  
• did you ever take any of the mechanicals of the engine apart, like timing chain off, or more likely was the dizzy taken out and hence maybe put back incorrectly?
  
• if the computer is sequential injection are the injectors wired to the correct injector plugs? (I mean so its not firing injector 8 when it should be firing injector 1)
  
• remember I said I know nothing about this motor, but if you have a dizzy is the cap on in the correct orientation and check that it is not cracked or damaged (inside and out)
  
• dizzy or not, are the spark plug leads going to correct numbered cylinder?
  
• after some attempts at starting, turn it off and quickly pull a plug, is it damp/wet or smell petrol? If it is, and you know you're getting spark in that cylinder, then the spark timing is wrong, refer cam/crank sensor.

If you answer the above points with confidence that will go a long way to reducing the areas to look.

Ben

[Modena]

there is a description in this thread of how the cam angle sensor should look;

AU II XR8 Cam position sensor - www.fordmods.com

[Modena]

does your cam sensor look like this, with the slot and rotating assembly facing directly forward?

[Modena]

also I read somewhere to check some sort of toothed ring on the balancer, as it can slip and hence be out of alignment with it's marks? seems possible too since the car had a shunt....

[stephen low]

Ben

Thanks for the comments.

Am led to understand the cam sensor does aid in setting injector timing but have also read that if it is out the system compensates and the car should still run but not as well as it might.

I'm not so convinced myself so might still play on this. Set up does look like your photo so have to be close. Might be pointing around 7 o'clock will check.

Fresh fuel and it is an EFI motor.

Engine dis-assembly ha ha ha but you might not know the history of this motor. My accident that forced the rebuild also caused one passenger engine mount casting to snap on the block.

Engine had a full strip down and rebuild into a replacement block. However given Don Stafford did this, I'd hope like crazy he got the re-assembly right.

Loom was played with but no chance of a change in the injector links.

Did double check the lead layout, might recheck just for comfort but don't believe these are wrong either.

Had read too about slipping balancer I thought it was. No idea how to check this but have worked from #1 piston at TDC comp for the cam sensor reference so unless it's location feeds to the crank sensor, being misaligned shouldn't cause grief.

Will continue to play.

Cheers

Steve

[stiffy]

Hi Slowly,

I know FA about motors but sometimes it is best to start at the

very beginning.

1. How was the motor stored, i.e. plugs in and inlet/outlets covered

2. Was the motor rotated regularly

3. Was it lubricated when rotated

4. Was the motor started after rebuilt

5. Welco Engine Reconditioning (past Shelbyfest Sponsor) do good work,

the rebuild was quite stock from memory so no issues there

6. Have you changed anything since the rebuild

My 2 Cents worth

Stiffy

[damage]

Try pulling the plugs to make sure they are clean, sometimes they can end up with oil on them from the assembly and not allow them to fire.

[sambo]

Slowy, have you asked Don whether it was assembled ready for a first start? I'd definitely be speaking to the engine builder in this instance.

[stephen low]

It was an R&R job on the whole motor albeit I had Don fit aftermarket alloy heads so should all be good to go with the ancillaries attached.

Fresh plugs in it and it is acting like there is a mis-timing occurring, but whether that is spark or fuel or both I haven't worked out.

Given it was a Wellco build you'd like to think Don hasn't misaligned the timing chain by a link for example but I do not believe that is the case.

Assuming the cam sensor was correctly aligned at refit but my removal has now misaligned is the only variable between what I received assembled and have taken off in between times. Else it has been simply to refit the upper manifold and various intake sensors, reattach leads and the fuel supply..

The loom rework had the loom laid out around the various fitting locations previously set for so I can't see this as an issue.

Anyone own one of those Ford cam sensor tools as perhaps the accurate way of ensuring cam sensor refit?

Any other suggestions guys?

It is frustrating the heck out of me cause I've got to be that close!!

Slowy

[Modena]

Have you checked fuel pressure? and checked the plugs?

[sambo]

If it's EFI can you check the engine management system for fault codes?

[stephen low]

Ok guys

Young bloke came home from uni early so I got him to hold my phone to hopefully show this recording.

Possibly residual fuel with the first bang on cranking then into the normal pattern of hits and misses.

restartstatus30514_zps0e125489.mp4 Video by slowy59 | Photobucket

Clearly wants to start but something is holding it back.

Comments please.

[Modena]

hard to tell from phone quality audio, but sounds like it might need a can of compression

[renovationinnov]

sounds like abit of start you bastard is needed
im thinking fuel
rob

[damage]

A bit hard to tell from the video but couldn't hear the fuel pump running in between start up attempts, I would put a fuel pressure gauge on it and make sure that fuel pressure is there both on ignition and during cranking.

I just had the same issue on mine and ended up putting a one way valve in my fuel line to keep pressure after the initial pump prime. If you don't maintain pressure the injectors won't get enough fuel through to start a cold engine.


Have you tried squirting fuel or aero start into it to see if it will fire that way.

[dhs.buckley]

Just thinking back to my Xh 5.0 v8, it had gas&fuel and it backfired and wrecked the airflow sensor,(ran very lean and was a bastard to start) maybe just try unplugging the airflow sensor as the computer for the fuel side goes to a full rich program without the airflow meter from memory.
it will run ok ,but it will be pumping heaps of fuel in.

[stephen low]

Anyone with a scanner that would care to come over and tell me what faults might be showing up on the beast.

Thought I'd detected the cam sensor as being out of correct position but it wasn't.

Had my young bloke turn the engine over and I played with the sensor position whilst cranking.

This didn't seem to suggest any location as creating more likelihood of starting.

So back to square one again.

Help!

Slo

[Modena]

Have you checked fuel pressure yet?

[justcobra]

Can anyone run a tape measure .bevel guage for the top wishbone/horizntal bar which has a Jag front end .G Force and RMC have basically the same front end.
I tried to get this information from the President from the Club Cobra in Victoria and nothing has arrived.
He has got a RMC -single stacker chassis.
I am working from photos and to maintain some form of accuracy I need some concrete information in the form of numbers before I get carried away with a angle grinder.

[stephen low]

What measurement are you specifically chasing?

Its not clear to me from your description above.