Engine won't fire until I stop cranking? (Timing Issue?)

samg1988
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Engine won't fire until I stop cranking? (Timing Issue?)

Postby samg1988 » Sun Apr 02, 2017 5:12 pm

Wondering if anyone can help me.

I have an engine swapped Ke25, running a 4age with twin carbs. Timing looks to be all set from TDC correctly.

The engine cranks, but doesn't seem to want to kick into life until I actually stop turning the key. At which point it coughs but of course the key is now no longer cranking the engine.

I might try the starter relay trick, but I'm stabbing in the dark really. Has anyone had something like this before?
Last edited by samg1988 on Tue Apr 25, 2017 1:17 am, edited 1 time in total.

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jondee86
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Re: Engine won't fire until I stop cranking?

Postby jondee86 » Sun Apr 02, 2017 11:49 pm

Try spraying a bit of engine start fluid down the throttles while cranking. Works
for funny cars with huge blowers, so might work for you :)

If not, check to see if you have fuel on the plugs after cranking. While you have them
out check to see if the plugs are sparking. What kind of ignition system are you running ?
How much advance is dialled in when #1 is at TDC ?

Cheers... jondee86
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samg1988
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Re: Engine won't fire until I stop cranking?

Postby samg1988 » Mon Apr 03, 2017 10:43 am

Thanks jondee.

Checked each spark plug one by one, and also by rotating the dizzy to check the plugs are wired correctly in the firing order 1342. All good there.
Plugs smell like they are getting fuel.

I also added the starter relay mod today, which interestingly now gives me the sound of the starter solenoid when the battery is drained. I didnt have that before... the car would just slowly crank to nothing.

This being my first time with twin carbs, they aren't set up at all. I had planned on trying to get the car running then over to a specialist.
I was getting about 3-4psi fuel pressure, so I've upped that to 5-6 to see if it made a difference.

With both of those things tweaked, it's starting to nearly shake its way into life. My battery keeps draining though... seemed so close!
I'm actually wondering if my battery has anything to do with it. I have a Powervamp C220 like this one relocated to the boot.

http://www.ebay.co.uk/itm/PVR22-Clubspo ... 7675.l2557

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jondee86
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Re: Engine won't fire until I stop cranking?

Postby jondee86 » Mon Apr 03, 2017 1:54 pm

If possible, you need to check the voltage at the starter motor while cranking. You may
have some voltage drop due to the cable run from the boot. Couple that with a battery
that is not fully charged, and the starter could be pulling the electrical system voltage
low enough to stop the ignition system sparking until you let go of the key.

Also, it is normal for the ignition timing to be retarded to around 10 deg BTDC while the
engine is cranking. This, plus some starting enrichment (choke with carbs) is what makes
the engine easy to start. If you can figure out how the choke works on your carbs, make
sure it is activated.

If the ignition is too far advanced while cranking, the spark will occur before the piston
reaches TDC and slow the engine... sometimes even stop it dead while cranking. If the
starter sounds like it is really struggling to turn the engine over even when the battery is
fully charged, retard the timing by turning the distributor clockwise unlit it cranks faster.

Otherwise, get some jumper cables and use both batteries in parallel :)

Cheers... jondee86

PS: If the carbs have float bowls, then 2-3psi should be fine.
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SR85DET
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Re: Engine won't fire until I stop cranking?

Postby SR85DET » Wed Apr 05, 2017 6:56 am

This might seem elementary but do you have a choke on the carbs that is set up. Are you giving a few pumps of the throttle to inject some fuel? Maybe your fuel pressure is bleeding off badly. Does it help if you hold the throttle open when you first start it incase it is flooding while sitting.

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Re: Engine won't fire until I stop cranking?

Postby samg1988 » Sat Apr 22, 2017 1:34 pm

Update to this. Thought it might be battery related, so increased the gauge of cables from the boot. Not much better.

Started a compression test... 120psi on cylinder 1 and 2.
Battery ran out after that...

From what I'm reading 120psi is no good to even start. This engine was "rebuilt" by someone else. Feels stiff in places when turning over by hand but not a struggle.

Wonder if I should take the plunge and look at a new engine?

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Re: Engine won't fire until I stop cranking?

Postby jondee86 » Sat Apr 22, 2017 2:33 pm

Compression test will show around 180psi on a fresh engine, The recommended service
limit is 140psi. If you only have 120psi your engine is in need to life support :) The only
thing that might get it started (providing you have spark while cranking) will be a squirt
of "Start Ya Bastard" which is the automotive equivalent of defibrillation paddles :)

Image

Otherwise jump starting with a larger capacity battery might work. An engine with low
compression will still run if you can get it started, but it won't get any better. So, as you
say... time to look at getting the engine rebuilt.

Cheers... jondee86
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Re: Engine won't fire until I stop cranking? (Timing Issue?)

Postby samg1988 » Tue Apr 25, 2017 1:27 am

Thanks again jondee.

Had another look last night and got the engine just about spluttering into life. I think the cause of my issues are the timing.

I have the crankshaft set at 0, and the cam gears at TDC. Piston 1 is definitely on its compression stroke. I have also lined up the dizzy rotor with the first spark lead.

Image

Image


I think some of my issues come from what's inside the dizzy. This is a modified Pinto distributor to fit the 4age (done by someone else). The vacuum advance has been removed. The connection points seem move freely inside the dizzy, as you can see in these photos. I can move them and they stay where they are... I have no idea if this is normal or not.

Image

Image

My guess is that these are the points for the vacuum or mechanical advance? These would move counter clockwise to advance the engine?
I don't know where their 'starting' position is though.

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Re: Engine won't fire until I stop cranking? (Timing Issue?)

Postby totta crolla » Tue Apr 25, 2017 3:12 am

Have you checked that the distributor sensor trigger is correctly positioned for the plug it should be firing ?
My guess would be that each of those 4 prongs (triggers ?) passes the sensor and each prong is related to a particular plug lead.
Generally the advance mechanism on a non-ecu distributor is done by weights, springs, centrifugal force and vacuum.
Assuming the prongs are triggers I can't see any reason why the trigger mechanism would turn independently of the rotor arm. That said, it is after all a Ford part...

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Re: Engine won't fire until I stop cranking? (Timing Issue?)

Postby jondee86 » Tue Apr 25, 2017 3:30 am

This is a picture of a Pinto mechanical distributor with vacuum advance...

Image

If all the vacuum advance parts have been removed (as is apparently the case with
distributors modified for use with sidedraft carbs), then the lugs that I think you are
referring to are on the centrifugal advance plate.

The top part of the shaft rotates on the bottom part when the weights are moved out
by centrifugal force as the shaft rotates faster. The weights are returned by springs
when the shaft slows down. So on the bench you should be able to twist the top of the
shaft while holding the gear at the bottom and feel resistance from the springs. There
may be some free movement in the plate before the springs start to resist.

When the centrifugal weights move out they cause the plate holding the ignition points
to rotate by a certain amount, and this changes the position of the points rubbing block
on the cam on the distributor shaft, advancing the ignition timing. Base timing will be
something like 10degBTDC and full advance will be something like 35degBTDC.

The ignition contacts (points) need to open by some specified gap (which I don't know)
to generate the spark and set the dwell. The points need to be clean and flat (not with
a big pit on one side and a peak on the other side).

When you are cranking if the engine turns over fast and easy, try advancing the timing.
If the engine turns over slow with the starter really grunting and sometimes kind of
stalling as if the effort is too much for it... retard the timing.

Cheers... jondee86
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Re: Engine won't fire until I stop cranking? (Timing Issue?)

Postby s24a » Tue Apr 25, 2017 4:30 am

That distributor is a Bosch unit. Maybe they used them on some Ford Euro Pintos, but I really don't think so.
It looks like it probably came from a VW/AUDI application as it is a head mounted distributor (I have one with identical reluctor setup in a Renault 807 crossflow engine in my Lotus Europa).

There are for reluctor "wings" and if you look close there are also four pickup wings on the pickup coil. All four cross together at the same time in rotation, and this supposedly makes a stronger low rpm voltage pulse than a single pickup coil setup would.
Having been into the Bosch distributor on the aforementioned Renault engine (R18i distributor), I made it full electronic control by wiring down the advance plate to the shaft plate with safety wire. I am going to guess your buddy did not do that as you can move your advance plate and it should not move at all.
This will cause you great grief in trying to set or maintain any sort of correct timing.
You need to remove the rotor, unscrew and remove the upper plate to get to the advance plate area below, and pin those two pieces together.
Then reassemble and retime. It should work then.

Hank
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Re: Engine won't fire until I stop cranking? (Timing Issue?)

Postby totta crolla » Tue Apr 25, 2017 9:46 am

Image

This is a different type of Ford Pinto distributor, from a late Ford Sierra with fuel injection I believe.

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Re: Engine won't fire until I stop cranking? (Timing Issue?)

Postby samg1988 » Tue Apr 25, 2017 12:04 pm

^ Yeah this is the one I have. With the same ignition module wired in currently too.

So from the sounds of it, these 4 prongs shouldnt really be able to move at all...

I did find this link about taking out vacuum advance in this very dizzy, but it doesnt mention locking in this part.
http://nw.rhocar.org/tuningdizzy.htm

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Re: Engine won't fire until I stop cranking? (Timing Issue?)

Postby totta crolla » Tue Apr 25, 2017 12:36 pm

samg1988 wrote:^ Yeah this is the one I have. With the same ignition module wired in currently too.

So from the sounds of it, these 4 prongs shouldnt really be able to move at all...

I did find this link about taking out vacuum advance in this very dizzy, but it doesnt mention locking in this part.
http://nw.rhocar.org/tuningdizzy.htm


It could be that the springs are either missing or broken.
Does the part with the 4 prongs on move independently of the shaft ?

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Re: Engine won't fire until I stop cranking? (Timing Issue?)

Postby samg1988 » Tue Apr 25, 2017 2:17 pm

Just spoke to the guy who sold the diy to me a while back. Apparently this should be spring assisted. Must have come off... Hopefully it's not too tricky to fix.

To be continued...

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Re: Engine won't fire until I stop cranking? (Timing Issue?)

Postby s24a » Tue Apr 25, 2017 3:28 pm

Just spoke to the guy who sold the diy to me a while back. Apparently this should be spring assisted. Must have come off... Hopefully it's not too tricky to fix.


You have a fully electronically controlled spark advance. Which depends on a correct and CONSTANT ANGULAR POSITION trigger from a sensor.
WHY would you want/need a "spring assist"? This sounds very dodgy, to say the least.

Best thing to do is to remove the mechanical advance weights and replace them with safety wire to lock down the mechanical timing.
Then take a screw and through a hole in the upper advance plate (the one that the vacuum advance diaphragm unit pulls) mechanically fix it to the stationary plate below.

Now you have a fixed spark distributor, which you now time to get your fixed startup advance and let the ECU calibration do the rest.
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Re: Engine won't fire until I stop cranking? (Timing Issue?)

Postby totta crolla » Wed Apr 26, 2017 3:13 am

The distributor in question is fully mechanical, the sensor is simply a trigger for the coil and replaced the unreliable 'points' type trigger.
I agree with the above statement about fixing the advance, trying to get the correct advance curve for a particular engine using springs is a complete PITA !
Once the plate is locked into position your ignition timing will be set in the position that gives best power, if that is what you are after, and will typically be 30 - 35° advance. Timing adjustment is simply done by turning the distributor. This will be approximately double the advance the engine is looking for when starting so expect it to be difficult to start.
Make sure that you index the drive gear to the shaft before removal as it needs to go back in exactly the same orientation.

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