3.9 v8 timming update

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smudge67999

Active Member
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330
Hi guys i posted an issue im having with my r/r classic 3.9 v8 i have re-posted as i have now made two videos one explaining what i have changed and how i have set up timming second link is the result .please take a look and see if im right or what else could be the problem.thanks u-tube post and the next video is motor turning over
 
Timing looks fine.

No idea what's going on with the coil location & it looks like a brown wire's wrapped round the king lead as well as a cable tie but get rid of the two scotchloks & either crimp join or solder & tape/heatshrink the joins.
They're well known for causing electrical connectivity issues.
ETA Looks like a lot of insulating tape round the other coil wires. Is all well with any joins under the tape?

Some of the original checks need to be done again.
Are the plugs wet after the cranking?
If you use a spare plug on one of the leads & hold it against the block is it sparking?
I know I keep banging on about it but did you try & did easystart make any difference in this latest attempt?
 
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Thats correct to set initial timing but its possible to be a long way out as you cannot see where the trigger point is. I have always left distributer loose enought to move by hand and adjust it by hand a little at a time until it starts, once it is running I set timing correct with a xenon strobe light (previouslty connected up). This is where your previous check is critical to make sure TDC is correctly marked on crank pully. I always paint the pointer and marks on crankshaft pully with white paint/tippex to make it easier to see.
 
Ratae said:
Timing looks fine.

No idea what's going on with the coil location & it looks like a brown wire's wrapped round the king lead as well as a cable tie but get rid of the two scotchloks & either crimp join or solder & tape/heatshrink the joins.
They're well known for causing electrical connectivity issues.
ETA Looks like a lot of insulating tape round the other coil wires. Is all well with any joins under the tape?

Some of the original checks need to be done again.
Are the plugs wet after the cranking?
If you use a spare plug on one of the leads & hold it against the block is it sparking?
I know I keep banging on about it but did you try & did easystart make any difference in this latest attempt?
Click to expand...
Hi i pulled the fuel relay and sprayed easy start no diffrence .soon as i put relay back in tries to catch .i regapped the plugs and made no diffrence. Do you think the plugs could be shot after all the turning over.
 
Ratae said:
Timing looks fine.

No idea what's going on with the coil location & it looks like a brown wire's wrapped round the king lead as well as a cable tie but get rid of the two scotchloks & either crimp join or solder & tape/heatshrink the joins.
They're well known for causing electrical connectivity issues.
ETA Looks like a lot of insulating tape round the other coil wires. Is all well with any joins under the tape?

Some of the original checks need to be done again.
Are the plugs wet after the cranking?
If you use a spare plug on one of the leads & hold it against the block is it sparking?
I know I keep banging on about it but did you try & did easystart make any difference in this latest attempt?
Click to expand...
Hi also to some of your questions .yes plugs were wet. And tbere is a spark at plugs.will sort the other issues out .u pointed out thanks for yiur helpo
 
smudge67999 said:
Hi i pulled the fuel relay and sprayed easy start no diffrence .soon as i put relay back in tries to catch .i regapped the plugs and made no diffrence. Do you think the plugs could be shot after all the turning over.
Click to expand...

No.
Sort the wiring.
Then leave the relay in & try the easystart again.
 
FWIW the timing looked retarded, the rotor arm should be past No1 at TDC so you're probably a tooth or maybe two out on the dizzy drive.
That engine sounds like it is struggling to turn over, is the battery up to the job? It should spin quicker than that.
Coil location is unusual.
Not sure how much advance you can dial in but I would look at advancing it and trying again. Also, it is easy to flood these engines if they don't catch, if you can smell the fuel try cranking with the throttle wide open. Alternatively, pull the plugs and warm each pot with a heat gun to evaporate the fuel. You could heat the plugs in an oven then put them in and give it a crank but the cold block will suck the heat off the plugs really quickly.
HTH
 
Ratae said:
Fingers crossed!
Click to expand...
Hi so ive corrected all the wiring and crimped .and sorted coil bolted it to wheel arch. Tried to crank it with fuel relay in and easy start was better but then it back fired and then nothing just turning over. So take a look at the video link via u-tube. I think it may be spark problem as crank over white spark and sometimes its there and other times nothing.
 
classic kev said:
FWIW the timing looked retarded, the rotor arm should be past No1 at TDC so you're probably a tooth or maybe two out on the dizzy drive.
That engine sounds like it is struggling to turn over, is the battery up to the job? It should spin quicker than that.
Coil location is unusual.
Not sure how much advance you can dial in but I would look at advancing it and trying again. Also, it is easy to flood these engines if they don't catch, if you can smell the fuel try cranking with the throttle wide open. Alternatively, pull the plugs and warm each pot with a heat gun to evaporate the fuel. You could heat the plugs in an oven then put them in and give it a crank but the cold block will suck the heat off the plugs really quickly.
HTH
Click to expand...
Hi take a look at this video i done today.im thinking it may be spak problem.
 
classic kev said:
FWIW the timing looked retarded, the rotor arm should be past No1 at TDC so you're probably a tooth or maybe two out on the dizzy drive.
That engine sounds like it is struggling to turn over, is the battery up to the job? It should spin quicker than that.
Coil location is unusual.
Not sure how much advance you can dial in but I would look at advancing it and trying again. Also, it is easy to flood these engines if they don't catch, if you can smell the fuel try cranking with the throttle wide open. Alternatively, pull the plugs and warm each pot with a heat gun to evaporate the fuel. You could heat the plugs in an oven then put them in and give it a crank but the cold block will suck the heat off the plugs really quickly.
HTH
Click to expand...
Hi just read what youve said.about being a tooth out. But as long as its near to number 1 on dizzy and as long as i can rotate in both directions so number 1 on dizzy can rotate before and after the rotor then basically it should fire uo.then once startee just adjust .wud this be the case
 
Appreciate it's a new dizzy so presumably a new rotor arm - but take the dizzy cap off & do the coil main lead to just above the centre of the rotor arm & crank.
You'll need someone to crank it for you while you watch.
Shouldn't be a spark jumping the gap.
 
Assuming you are happy that you have the basic bits right it looks like you need to focus on the spark bit of the cycle.

The ignition system is very simple on these engines. The loss of spark suggests that you are either losing the trigger for the coil field to collapse to induce the spark or the coil is not able to generate enough voltage to create a spark. In the first case, the problem may be the ignition amplifier or the inductive pick up inside the distributor. In the second case, the issue will be the coil. If you have a "performance coil" take it off and put on a standard coil.

In both cases, damaged wiring and corrosion are possibilities. So I think I would suggest the following.
1: Pull the battery off the car and get it on charge. You need all the power you can get.
2: Check the resistance of the inductive pick up and check/set the reluctor air gap.
3: Check the wiring, especially the LT wires to/from the ignition amplifier.
4: Once the battery is charged, put it back on then run all of the standard ignition checks - if you do a search in the V8 section there is loads on this.

The reference to a backfire suggests the ignition timing is not correct or possibly there is a valve issue. Assuming there is no valve issue it points to ignition timing. The V8 is quite tolerant, it will run with zero advance but it will happily take 10 or 12 degrees of advance although the correct advance is only between 2 and 6 degrees depending on engine spec.

Good luck with it.
 
Backfire or flashback?
Much the same as can occur with LPG systems where the gas vapour is introduced by a gas ring or Blos carburettor prior to the plenum chamber esp if the changeover from petrol to gas is done on an open throttle.

ETA. Out of curiosity, what's the extension tube on the mouth of the plenum - the thing held on with the grub screw in the top?
 
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