Throwing a line in the water while its thunderstorming. Can't do any other testing until tomorrow.

Car died today on the way home. Replaced the fuel pump when I got home, made no difference. Checked both the relays in the trunk. Tank has fuel.

With a wire pulled and a plug installed I get a pretty consistently white spark. I know there are 12 cylinders but it seems like there is a pretty good delay between sparks.

12v on positive and negative of coil. 5500 phm on the secondary side of the main coil, didn't check the front coil. Primary side on both coils was 0.8 ohms

When I first got out on the side of the road, the negative lead to the amp was extremely loose, basically off. Made no difference when it was reconnected.

No obvious noise that would lead me to believe it totally broke and lost compression.


Would like to do better inspection of coils and pop the dizzy cap tomorrow. Seems like it has fuel and has spark, so....poor spark? Timing? Any ideas can't hurt. Thanks all

other notes: Car has had stutter problem when cold for about 6 months. Requires very light acceleration until warm or it will bog.

update 1: pickup resistance is 3.8k ohms
update 2: Had GF start car while i checked injectors with stethoscope. Nada
update 3: Both fuel pump and main relays have an audible click when jumped off the battery. The diode on the main shows open on one side and 545 ohms on the other.
update 4: Just kidding, the injectors are ticking (seemed really slow tho?), I just checked the pickup resistance and forgot to plug the wire back into the amp.
update 5: Pulled the vacuum hose on the LH pressure regulator. Fuel leaked out.
update 6: CTS reads 1625 ohms at 75F ambient temp. No change when jumped.
Update 7: ordered LH reg. Pulled line at RH red and turned key to on to verify fuel flow to rail. After reconnecting and priming 3x it sounded a little better but still no start.

 

Sounds like it may be ruptured diaphram with low fuel pressure as a result.

 

That would be my conclusion as well, FWIW


Cheers
DD

 

I've heard of people tossing the RH regulator. If I replace the LH with the RH, how is that hole typically capped off?

 

You can ditch the RH regulator you can't use one in place of the other. Different functions, different operation. If the LH regulator fails you have to replace it with the correct part.

Cheers
DD

 

How damning is a bad regulator generally? I don't wanna spend $75+ and wait a few days only to find I should have still been troubleshooting.

Seems like I've seen threads where this caused roughed running to no starts, but I have also seen threads saying regulators only ranges from 35-45 psi, so even broken it should run somewhat.

 

The LH regulator if weeping fuel into the vac tube is most unlikely to be holding working fuel pressure, and is definitely faulty, even in the unlikely event that replacing it does not fix the no start, it will for sure let you down soon. Also, IMO it has to be changed for safety apart from anything else. Raw fuel into the intakes is not a good plan...
Greg

 

The fittings on the two regulators are different as is the set pressure.
If you play around a bit and a with bit of cut and shut you may be able to rig the R/H unit up in place of the bad one and the slightly higher pressure of the replacement won't make any practical difference.
The R/H unit could be removed and the inlet and outlets of that unit simply joined by way of a nipple.(1/4" bspp l think) That Inlet fitting is same as inlet on L/H unit so it could hook up there easy enough, just leaves outlet to rig up.

 

Replaced the LH regulator and return line coming off of it. Still no start.

Once again, can see spark if I pull a wire and hold it off the inlet manifold, i have fuel to the rail, new pump, and I can hear the injectors click on when starting and when the throttle is opened.

So, bad fuel pressure still, weak spark, or spark off time?

EDIT: Starting fluid sprayed into a TB makes no discernible difference when cranking.

 

Fuel is not your issue. Spark or timing.


Check that you are getting a consistent timed spark to each plug. A shorted rotor will spark once in a while. Or replace rotor.

 

Pull the HT lead from the input of the distributor, you should be able to push the metal terminal out of the boot (or insert a bit of thick wire) and hold it about 1/2" away from the intake manifold and crank, you should see a good fat blue spark all 12 of them.

 

Ladies and Gentlemen...I found the problem.

I was popping the coil and amp off to take a poke at inside, as I'm not so inclined to stand out in the mosquitoes after drinking a bit. I grabbed the dizzy cap on the off chance it was cracked or something.

Well, I wasn't expecting such an obvious issue. I can't believe it was sparking at all. Remember I said it was dim and there was a weird delay between sparks? Well I also noticed a bit of an arcing sound today, so I thought I'd check out some ignition components.

Pics to come. Hint: The dizzy cap is to blame
The breather sleeve broke and remains in the hose Allowed this inner piece to slide down Sleeve broke here too. It remains in the hose
​​​​​ Rotor smacked the plastic once it dropped

In the FBI they call this a clue I can't believe it was sparking at all...if this ain't the problem I'll be dipped

 

I'll be damned !

Cheers
DD

 

Fair Dinkum.

Never seen that one.

Surprised it ran at all.

The "Made in England" sticker had me going for a minute.

 

Astonishing. Just shows us all, first thing on a no start is to look inside the dizzy! Good that the leaking reg is done though. I have found that non-Lucas dizzy caps often have the vent tubes just pressed in, and when I put on the vent tube it pushes down, so I araldite them; but I never realised the thing could jam the rotor.
Greg

 

Yeah and now that I look at it, its a shoddily cut out piece of paper with some glue. Too bad that glue held up better than the stuff they used on the breather!

I really didn't even think the dizzy was worth looking at. The pickup was within spec, so what obvious issue could really be hiding under the cap other than perhaps a crack?

Anyway, this is a Beck Arnley part, you have been warned. I recently sent back plug wires that didn't fit my MGB from them, so they are on my sh$% list now. Seems like Greg has the right idea gluing his caps up just in case.

Oh well, was certainly worth the laugh when I opened it up and perhaps the new reg will solve my cold bogging issue. Thanks for the input everyone

 

I always add a dab of glue to my nipples as well. (tee hee....that sounds sorta weird) The darn things loosen with age and then, when you want to slip the hose over them they won't hold still, just as Greg mentioned. But it never even dawned on me that fouling the rotor could occur.

Cheers
DD