Ph1 revival

Struggler said:

The bodge is still there. it basically bypasses the relay and provides a permanent 12v to the coil pack. To be honest, it may remain long term depending on what amperage the coil pack pulls.

The potential fallout would be adding a drain to the battery but the feel appears to cut out when key off.

I cut the battery isolator when I leave the car so in this case it would be fine either way.

Click to expand...

Couple of things , if you’ve shunted to the perm power then it will drain as coil pack will remain powered , but if you shunt to the ignition side power then it’ll turn off . But as you say , those two different circuit's are protected by different fuse ratings so be cautious.

Getting back to your issue , I suspect that the relay control wire which is an Earth control via the ecu ,that wire needs to be checked for continuity and resistance.
Fuel pump controlled earth by Pin 68 of ECU. ORANGE wire.

I've shunted to the perm live. bridging to the switch could draw too much current for the wiring and blow a fuse. I turn the battery isolator off when the ignition is not on so it wont drain the battery. But yes, i should probably find a more appropriate solution.

Interesting to know that the relay is controlled via the earth. I will have to find which pin on the ECU that will be.

Note that this is a ph1 that has slightly different pinning on the ECU - also I am using a GEN90 aftermarket ECU. The fuel pump is controlled by pin9 rather than pin68 but i was getting 12v at this pin. But it is the coil pack relay that is the issue, is this on the same circuit?

Struggler said:

I've shunted to the perm live. bridging to the switch could draw too much current for the wiring and blow a fuse. I turn the battery isolator off when the ignition is not on so it wont drain the battery. But yes, i should probably find a more appropriate solution.

Interesting to know that the relay is controlled via the earth. I will have to find which pin on the ECU that will be.

Note that this is a ph1 that has slightly different pinning on the ECU - also I am using a GEN90 aftermarket ECU. The fuel pump is controlled by pin9 rather than pin68 but i was getting 12v at this pin. But it is the coil pack relay that is the issue, is this on the same circuit?

Click to expand...

Yes the fuel pump relay also sends the power to the coil pack, so dual function relay.
Yes pin 9 , I should have known lol , I run a ME221in my Ph1.

Yes check pin 9 then back to the relay.

Short update and unfortunately not a good one. I was a bit concerned how much it was chuffing out the oil breather when I got it started so run a compression test...

Cylinder 1: 50psi
Cylinder 2: 175psi
Cylinder 3: 180psi
Cylinder 4: 175psi

Checked and rechecked cylinder 1 hoping I had done something wrong. Even put a cap of oil down the bore as a big jump after doing so indicates piston rings, it jumped to 125psi so I think its the rings that a dead.

Head has obvious just been reworked and leak tested, it could be that I installed the head gasket incorrectly but I think it's the rings... The one thing I didn't do!

So it will be engine back out again to change them. Never changed rings before and unsure if I should change them all or just the affected one, and is honing the box and absolute must? Can I do it all without dropping the crankshaft?

Pretty gutted tbh given how much work I had done to get to this part, only to have to backtrack and pull the engine again!!

That's disappointing.. how long has the engine been sat? It could be a stuck ring so you could try letting it sit with some penetrating oil in the cylinders for a day or so but it's usually wishful thinking.

Looking back at the pics on pg1 the bores don't look good, I definitely wouldn't put new rings in it without honing, it may need at least quite an aggressive hone to get those marks out.

To be honest, bottom ends are not my strong point, would you be able to elaborate on your last comment about the bores not looking good? are you referring to the slight pitting on cylinder 4? As that one was still coming up with good pressure.

Cylinder 1 was showing a little corrosion at the top but i would have thought these would be above the rings.

Finally - is it a terrible idea to just change the rings (and hone) on the affected piston? Or would i need to suck it up and change them all? (with maybe some 197 pistons ).

Put some 197 pistons in whilst you're in there

You'd be daft not to. The rings are the same for all F4R iirc

Cylinders are numbered from the flywheel end.. which is the low cylinder? There are some concerning marks on 1 and 4



What did the face of the block look like when you put the head on because in that pic it's minging?

You can see where the top ring stops with the piston at TDC from the ring of carbon at the top 10mm or so of the cylinders, your corrosion definitely is in the swept area of the ring(s).

You could pull the head off and try to dingle ball hone the bad cyl in situ but why risk It? I'm very much of the opinion of 'do it nice or do it twice' if that was mine I'd be getting the block honed (if the corrosion will hone out while staying within the service limit for piston-bore clearance, which TBH I would be sceptical of) and refaced and go again.

Looks like the corrosion on the top of cyl 1 is pretty bad. Prob be rebore and up a size in pistons or liners in the block to return to stock size.