| Author | Message | ||
     Benoit Leus Prolific User Username: benoitleus Post Number: 235 Registered: 6-2009 |
I just installed the gearbox on my '79 Shadow II. To reach one of the gearbox to engine bolts I had to remove the coil and some plug leads. I carefully marked the leads so I could reinstall them as they were. Just to be sure however I checked the correct firing order and discovered to my dismay that the plug leads on my car where not installed as per workshop manual. I believe the correct firng order should be A1 (at one 'o clock)-B1-A4-B4-B2-A3-B3-A2. On my car however they are as such : A1-A2-B3-A3-B2-B4-A4-B1. I bought the car with the plug leads in this position and never checked their correct installtion as it starts and drives well. However I have always had a problem with a slightly rough idle and plugs with different colours. Also the engine was never that quiet. Once on the run it goes well. Could it be that I have been so foolish to run it with the leads wrongly installed ? Benoit | ||
| Bob Reynolds Grand Master Username: bobreynolds Post Number: 372 Registered: 8-2012 |
That's the reverse order. Has this got anything to do with today's date?  Are you sure you haven't been travelling around with it in reverse gear? | ||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 1494 Registered: 6-2006 |
I had that before and the spark plugs were also fitted with the the ceramic ends in the cylinders . . Looked strange but It ran ok.  | ||
| Chris Browne Prolific User Username: chrisb Post Number: 242 Registered: 2-2010 |
Hi Benoit, Your first sequence is simply the second sequence reversed. The leads are in the correct order as long as your distributor is turning the right way! Kind regards, Chris | ||
| David Gore Moderator Username: david_gore Post Number: 1955 Registered: 4-2003 |
Reminds me of the reputed old WW2 trick of disabling 4 cylinder Jeep petrol engines by swapping the plug leads on cylinders 1 and 4. The engine supposedly will start and idle normally but will stall as soon as the clutch is engaged to move off. The reason being cylinders 1 and 4 are firing on the intake stroke rather than the compression stroke and do not provide the power needed for moving the vehicle. Never tried this in practice but it is still in the back of my mind if the opportunity ever arises. | ||
| Omar M. Shams Grand Master Username: omar Post Number: 561 Registered: 4-2009 |
My 59 Cadillac has the firing order stamped on the intake manifold but the actual firing order was set differently by the previous owner. When i investigated the net I learnt that the firing order which the previous owner had set is the better one that everyone now uses. Having said that - someone needs to give Benoit a comprehensive answer. In the absence of that, here is my attempt: Benoit - the correct firing order for your car is the standard one as detailed by the manual. Other firing orders will work but you must only choose the correct one. If then the engine runs rough - there will be other corrections that you will also have to make, like maybe the timing. Thanks Omar | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 1134 Registered: 5-2012 |
Benoit You must change your plug leads to the correct firing order. When you have done this you will probably find the ignition timing is wildly out. You may even find the engine will not start. My guess is using the firing order your car has, the timing will be retarded. So, set the correct firing order and then check the ignition timing. I would not worry about feeding your replacement HT leads through the channels. I dispensed with them a long time ago. I just run the HT leads directly to the spark plugs and clip them together, as is standard practice on most cars. This will turn a 1 day job into a 30 minute job. You can always do it the RR way at a future date, or when you come to sell the car. Please report back to let us know how you get on. Geoff | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 1135 Registered: 5-2012 |
Benoit With regard to Omar's point, I agree. There may be other adjustments to be made. It is quite possible the carburetor settings have also been changed to compensate for the wrong firing order. However, I would first just check the ignition timing to see how the engine runs before tuning the carbs. Geoff | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 1136 Registered: 5-2012 |
If you really have been running the wrong firing order, with ignition and carbs retuned to compensate, then you are in for a real treat. You will have gotten used to rough running and lack of performance, so when it is all corrected it will feel like there's a jet turbine under the bonnet. | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 1137 Registered: 5-2012 |
As a final after-thought, are you sure you have counted the firing order correctly. Maybe you have made a mistake. The direction of travel of the rotor arm on my car, from memory, is anti-clockwise. The firing order is counted from A1, in an anti-clockwise direction. My car is an earlier 74 SY1 but I believe the direction of rotation of the rotor is the same on the later cars. You could always pull the distributor cap off and get someone to blip the starter motor to make sure. It may be your firing order is correct and the rough running is a tuning or component issue. | ||
| richard george yeaman Grand Master Username: richyrich Post Number: 478 Registered: 4-2012 |
Hi Benoit I also have a shadow one 1974 not a Shadow 2 the A1 lead is approx three o clock on the distributor with the rotor moving anti clockwise the firing order is A1 B1 A4 B4 B2 A3 B3 A2 after you have done this then check your timing and leave your carbs alone good luck. Richard. | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 1857 Registered: 6-2009 |
I did the firing order diagram (including the rotation of the distributor) a while back when dealing with this area for the first time. Here it is:  Brian | ||
| Benoit Leus Prolific User Username: benoitleus Post Number: 236 Registered: 6-2009 |
A big thank you to everyone. I'll look into it over the weekend. Benoit | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 1858 Registered: 6-2009 |
Benoit, Good luck!! In reviewing my firing order diagram I decided that it did not include quite enough information were it to be needed by anyone completely new to this particular arena. Thus I made what I think are some improvements:  Brian | ||
| Robert Noel Reddington Grand Master Username: bob_uk Post Number: 931 Registered: 5-2015 |
Right left right left left right left right. Burble burble. Typical cross plane crank. Or Ferrari, right left right left right left right left. No burble. Flat plane crank. Twice the vibs as a 4 straight four. Limited to 4.5 litres. I told Ferrari to fit a V12 and stop mucking around with V8s. If the firing order is wrong it means at least 2 cylinders not firing it would be obvious. The actual position of A1 is not important as long as the firing order is right and timed right. However it's usual mechanic good practice to have as per factory. I had a guy who kept wasting my time with endless questions on how to fix his car. He didn't have a clue. I told him that the spark plugs were hammer fit ones not normal screw in type. I hope he tried to hammer them in because I was never going to earn any money from him. I dare say Paul Yorke gets the same, people who are not going to pay to have the car done, they want you to tell them how to do it, and borrow the tools. No frigging chance. But be polite and smile, it's not company policy to lend out tools and I can fit you in tomorrow, Mr you have car you can't afford Sir. Benoit while you are inspecting the said distributor remember to oil the bits, under the base plate. The dizzy has a drain hole so excess oil just drips out. So tissue paper around dizzy to soak up excess oil. Engine oil or ATF will do. Also pad in spindle under rotor arm. No need to remove base plate the oil will find its way on to the weights and the pivots via the gaps betwix the plate and the dizzy body. The oil will not harm the electronics but wipe off with tissue if oil does get on the module or other electric bits. Keep oil away from rotor arm and dizzy carbon brush. Else the carbon falls apart and the spring rubs a hole in the rotor arm. And car will run oddly. Then celebrate the maintenance with a cup of tea and Jaffa cakes. It is considered bad form to put a whole Jaffa cake in ones cake hole. Rolls-Royce owners bite them in half. I can get two jaffas in one go in my mouth. Also drinking tea from the saucer, it's not allowed you know. Comments about big mouths must be accompanied by a good joke. If it moves and is meant to, oil it. If it moves when it shouldn't tighten the bolts up and paint it. Some of the numbers on my leads have fallen off. ( hazard with old cars that, bits falling off ). I tried that dyna lettering tape but they fell off as well, most irritating. Maybe super glue them next time. One can always find something to play with on old cars, all part of the hobby. Where did I put sledge hammer. Last time I used super glue I stuck my finger to the kitchen table. Been sitting in my kitchen for 4 weeks now because the kitchen table is too big to go through the kitchen door even when the door is open. In WW2 one could be summoned to magistrates court for not disabling your motor carriage whilst parked. The normal method was to remove and pocket the rotor arm. I used various methods of disabling cars whilst working for the plod. The favourite was to rip out the plug wires and take them with me. One copper favourite method was to cut the wires to the fuel injectors. The idea being that when the villain gets back to his car it doesn't go so he captured. The damage to the car wasn't an issue because of the damage a bad man can cause when fleeing the police in a car. The Fire Brigade use the chop up the battery lead method with an axe. They will have the roof off the car with great gusto.The mere suggestion of pain and you got a convertible with a hard top but no hood and a chopped up battery. I wonder how the insurance companies view roof being chopped off. I have seen cars that were repairable until the roof got chopped off. One vehicle I was ordered by the court to disable permantely so we turned it upside down and ripped the rear axle off with a digger. I got a sense of satisfaction in that the owner of the vehicle a Nissan 4x4 had been ramming our cars with it. He caused me an enormous amount of work putting cars right. I keep the oil gauge as a souvenir. The nasty bad guy got 2 years clink. Quite right as well. Lucky he didn't injure some one. One of his family members went on the rampage after he got sent down. He threatened the cops with all sorts of violence. The fuzz just laughed in his face and nicked him as well, he got tagged and fined. I fought the law and the law won. Breaking rocks under the midday sun. The original version is the best. One of Crickets of Buddy Holley. April fools only applies in the morning. My mum told me, as I placed drawing pins on my sisters chair at tea time. Bang off topic but good fun and it's Spring. Another winter over. Oz is back to front. So it's Autumn down under. | ||
| Robert Noel Reddington Grand Master Username: bob_uk Post Number: 932 Registered: 5-2015 |
Oh forgot. A 4 cylinder engine with any two leads interchanged will not run on those two cylinders. Most 4 cylinder cars will start and run on 2 pots. But as Dave said as soon as any power is used the engine will probably stall unless it's revved hard. The engine will run like a 3 legged camel with a limp and not idle. 3 cylinders running and the car will drive sort of OK but sluggish. 1 and 4 Pistons rise together while 2 and 3 are going down. The dizzy will have 1 and 4 opposite each other and 2 and 3 opposite each other. 2 firing orders in use, can be 1243. But most are 1342. End cylinder fires, then a centre cylinder, then the other end cylinder and then the other centre cylinder. The firing order is governed by the order of the cams on the camshaft on ALL 4 stroke engines. To change firing order on a 4 stroke engine only the cam is different which is what RR have done on later engines. Suck squeeze bang blow. 4 strokes. Now get ones brain around a V16. | ||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 1495 Registered: 6-2006 |
Benoit, Appologies for my strange reply. Being April's Fools day and being a bit of a practical joker I just assumed the worst. :/ Robert . . I'm never like that actually. Being blessed with the patience of a saint ;) and you've ignored W Engines. Luckily individual coil packs negates any confusion . I suspect that as pointed out by others you must be reading the leads the wrong way. It is possible that somebody fitted them the wrong way before you bought the car but I would be mortally surprised if it would run at all let alone with a slight rock or misfire. Brian, can I suggest another change to your drawing. To be even more helpful On RR&B the leads are rotated so A1 is nearest the front and slightly to the right where A3 is on your diagram. The cap clip between A3 and B3 (on your diagram) and the vacuum around where A4 (on your diagram) is. It will not affect the running of course but it will help anybody checking or doing theirs. | ||
| Robert Noel Reddington Grand Master Username: bob_uk Post Number: 936 Registered: 5-2015 |
As I have got older I have got more patience. One tries to up beat and bouncy with customers but some really took the p**s. Benoit. When tuning a Shadow with carby toots, the mixture is best set to slightly rich. 14.6 instead of 14.7. This will give a good pick up. Which gives the illusion of more power. Also better mpg. Because the engine picks up nice less throttle is needed. It sounds counter intuitive but a lot of SU cars work better with slightly rich mixture. Some try set the mixture too weak thinking it saves fuel. Instead the idle is not quite smooth and the engine trys to bog down just off idle. 700 to 1000 rpm. Plus the air con can stall the engine. My car when the air con is engaged doesn't slow down that you would notice. I measured once it drops by 50 rpm on my car. An engine will try to use the amount of fuel it needs if not it will not be at its best. |
