Dexter
20-12-07, 03:13 PM
Hiya guys. Used to be an avid member off Roybacer but it appears to have gone. Had no idea Novaload had turned into PNG but anyway i need some pretty technical advice i think. Ive asked on migweb and everyone seems pretty unsure or reluctant to help so i figured id find a dedicated Nova site hence why im skulking on here!
Ill post the thread from the other site - I cant post pictures as i dont have enough posts yet! but i still have them on photobucket:
First Post:
Hello, my bro over in leeds is struggling to get his nova started after putting on twin carbs. This is what he's email me, warning its quite lengthy ;)
Hey there guys.
Ok ill give a quick basic rundown of whats gone on. I've literally just installed twin dellortos to my Vauxhall Nova 1985 1300cc SR. Now the carbs are piped up and fuel is getting right across both of them. They are being run by a mechanical fuel pump with a fuel pressure regulator plummed in between the mechanical pump and the first left hand carb. Now i have adjusted idle screws etc according to a book recommended to me by a fella of Mig. Which happens to be really useful. Anyway thats the basic mechanical side of the issue and im more or less happy that the carbs are able to at least be in a sufficient state to allow the engine to start and run (even if it doesn't currently idle.)
Now the main issue i have is whilst installing the carbs, i noticed numerous cables lying around the engine bay which wern't within the original looms. So i traced the cables back to the alarm system which was installed some time ago by its previous owner. Since its installation it has been disconnected and made redundant and had no effect on the running of the car when the old single carb was on.
So i proceded to remove the actual alarm to allow for later install of a electronic fuel pump which would be installed on the inside wing of the drivers side wing in the engine bay (im sure many of you would have seen this set up already.)
I disconnected the system and removed some of the redundant wiring for it including what looks to be an aftermarket relay which was lying in the engine bay (it really doesnt look genuine GM.)
Since the removal of the wiring i cannot get the car to start. The engine will happily crank away and the pump IS pumping fuel right across the carbs as ive taken off the various joints and made physically sure that fuel is getting through. There is 1/2 tank of petrol in the tank as well.
So my next thought was the ignition system. So i systematically removed each plug and tested it for a spark against the engine casing upon the engine crank. There is NO spark.
So tracing the problem furthur back i had a look inside the dizzy gave it a good wipe and cleaned the contacts fully then just to be sure sprayed them with a little WD40.
Again, nothing. So i removed the HT lead from the centre of the dizzy and tested this for any sparking on its crank. Again nothing. So just to clarify i dont think that there is a problem with the high tension side of it unless its the coil However when you read across the coil with a multimeter, the readings are 6Ohms which is within the acceptable range stated by haynes (6-9 ohms)
Now this is where it starts to get a little complicated. I began to check the low tension side of the ignition system, and i do realise that the alarm could have been cabled into this. I.e. the alarm must be disabled for the ignition system to be allowed to work. (An immobaliser effectively)
I'm pretty confident that the issue is within the wiring of the low tension circuit.
Picture 1
Number 1
This is just the clip that clips onto the coil. Just wonderd if the wiring is as it should be really (obviously you will have to look at the other pics to see the opposite end of it.)
Number 2
Is the coil
Number 3
Now this is one to note. This wire was in a chocolate block which im assuming had something to do with the alarm system.
If i put the voltmeter to this with the ignition on and the other lead to earth i get a nice 12V so im *guessing* that thisis the direct feed to the coil. Now as the wire is the same size nd colour as number 5 i connected both these up into the block and there is 12V getting to the coil on the bottom left side of the connector. All the wires on the coil plug (when plugged in) now get a 12V feed when the ignition is on. SO just to clarify the small black wire is the feed as far as im aware.
Number 4
Header tank coolant hose to top of rad.
Number 5
Now this is the wire that comes out of the connector that connects to the coil (Number 2) It has been snipped and USED to go in to the same chololate block as the live feed, however they were not in the same tunnel i.e. there were 2 chocolate blocks all togeather. As stated above this wire + wire number 3 are now connected up.
Picture 2
Now this is a picture of the connector that connects to the coil, the green wire goes into a loom near the passengerside headlamp which as far as i can tell is for the rev counter and thus needs no more attention. The rev counter worked fine when the car used to be running.
The wire top right is the one decribed in Picture 1 as number 5.
The two brown/red cables coming out of the same port - One goes down to a unit attached to the passengerside wing but changes the wire size and colour in the block shown in the picture below. The other wire from this goes straight to the dizzy. When the ignition is on both of these have 12V running through them. One directly to the bottom of the dizzy housing and the other to the small seimens black box cant quite fathom out what this is but from out of the box comes 3 other wires which go to another connector which also has 12V on each cable. From the connector 3 more wires run to the dizzy housing as the other previously stated along with the cable bottom left.
Picture 3
This is a picture of the inline connector as described above where the wire changes from the red/brown wire to the black wire which goes to the unit below on the passenger side wing. There is 12V here too. The black connector on the right is the coil connector
Picture 4
This is simply a picture of the two cables that run from the coil connector directly to the dizzy.
Anyway. I feel like i have 2 issues here, actually getting the car started. Secondly is that im really worried about drowning the carbs and engine with petrol! Any help is much appreciated
Alarm system
After working on it today, i have comepletley ripped out the alarm system, im unsure wether it was just an alarm or an immobaliser as well is i had never seen it working so i took the whole lot out. Its made no difference to the problem.
The only thing i can think of is that the battery is pretty flat now but will still crank the engine however i dont know if it would have enough voltage to allow the coil to excite the HT side of the ignition system. I would have thought honestly that the low batt wouldnt really stop this so im just clutching at straws really.
Any ideas or help is much apprectiated
Andy
Second Post:
Anyway.
Its not that! the problem is still there. All the way across the Low Tension circuit, at the coil, the idle stabiliser control unit and then onto the distributor i get 12V all the way and even at the contact points inside the distributor i get 12V at all them too.
The only place i dont get 12V is at the vacuum switch which is located on the top of the distributor housing this receives 6.23V and is fed from the idle stabiliser control unit by 2 wires: a brown and white/brown wire. This switch reads 4-6 ohms when it receives a 12V supply but with no supply it reads as an open circuit.
Ive gone through the wiring diagram in the haynes manual and everything checks out including the wire colours going to their specified locations.
The only thing i thought it might be was the vacuum switch
The continuity reading across the coil is within acceptable resistance (0.6 ohms) Haynes allows 0.6-0.9 ohms. So i'm relatively happy that the coil is in good working order.
The spark plugs are fitted and tourqued up to 15 lbft as recommended.
The HT leads are fitted in the correct order via haynes diagram
Now i took readings for continuity across the HT leads - the results are as follows and displayed starting from lead 1 & the spark plug closest to the camshaft housing which is the left hand side:
Lead 1 12.3 K ohms - slightly struggled to get this reading
Lead 2 11.4 K ohms - Easily got this reading
Lead 3 9.78 K ohms - Again little issue with getting this reading
Lead 4 10.36 K ohms - And again very little problems with this
The HT lead from the coil to the dizzy cap read:
11.44 K ohms.
All these readings look relatively similar, ive posted them as i was hoping if someone could tell me if they were acceptable resistances as haynes doesnt give me a figure to compare against.
For good luck ive even checked all the fuses in the car and they are all ok and are the specified values.
Which now leaves me thinking that the HT lead from the coil to the distributor is faulty as there is no spark when held to the engine casing upon a crank ( However the Ohm readings are similar to the other HT leads).
Or i've either ripped out a cable from the low tension side of the ignition circuit (which is also strange because the voltage is at each point it should be)
The HT leads need replacing but again the resistance of them all is very similar which suggests that they are OK
Something within the distributor could be faulty. However there is no spark coming from the coil ( which then suggests that the coil is faulty) - Again the coil reads within the resistance allowances stated in haynes.
Really would appreciate any help guys because if i dont fix it my mum is going to be really really ****ed off that i wont be home for christmas thats all!
Ill post the thread from the other site - I cant post pictures as i dont have enough posts yet! but i still have them on photobucket:
First Post:
Hello, my bro over in leeds is struggling to get his nova started after putting on twin carbs. This is what he's email me, warning its quite lengthy ;)
Hey there guys.
Ok ill give a quick basic rundown of whats gone on. I've literally just installed twin dellortos to my Vauxhall Nova 1985 1300cc SR. Now the carbs are piped up and fuel is getting right across both of them. They are being run by a mechanical fuel pump with a fuel pressure regulator plummed in between the mechanical pump and the first left hand carb. Now i have adjusted idle screws etc according to a book recommended to me by a fella of Mig. Which happens to be really useful. Anyway thats the basic mechanical side of the issue and im more or less happy that the carbs are able to at least be in a sufficient state to allow the engine to start and run (even if it doesn't currently idle.)
Now the main issue i have is whilst installing the carbs, i noticed numerous cables lying around the engine bay which wern't within the original looms. So i traced the cables back to the alarm system which was installed some time ago by its previous owner. Since its installation it has been disconnected and made redundant and had no effect on the running of the car when the old single carb was on.
So i proceded to remove the actual alarm to allow for later install of a electronic fuel pump which would be installed on the inside wing of the drivers side wing in the engine bay (im sure many of you would have seen this set up already.)
I disconnected the system and removed some of the redundant wiring for it including what looks to be an aftermarket relay which was lying in the engine bay (it really doesnt look genuine GM.)
Since the removal of the wiring i cannot get the car to start. The engine will happily crank away and the pump IS pumping fuel right across the carbs as ive taken off the various joints and made physically sure that fuel is getting through. There is 1/2 tank of petrol in the tank as well.
So my next thought was the ignition system. So i systematically removed each plug and tested it for a spark against the engine casing upon the engine crank. There is NO spark.
So tracing the problem furthur back i had a look inside the dizzy gave it a good wipe and cleaned the contacts fully then just to be sure sprayed them with a little WD40.
Again, nothing. So i removed the HT lead from the centre of the dizzy and tested this for any sparking on its crank. Again nothing. So just to clarify i dont think that there is a problem with the high tension side of it unless its the coil However when you read across the coil with a multimeter, the readings are 6Ohms which is within the acceptable range stated by haynes (6-9 ohms)
Now this is where it starts to get a little complicated. I began to check the low tension side of the ignition system, and i do realise that the alarm could have been cabled into this. I.e. the alarm must be disabled for the ignition system to be allowed to work. (An immobaliser effectively)
I'm pretty confident that the issue is within the wiring of the low tension circuit.
Picture 1
Number 1
This is just the clip that clips onto the coil. Just wonderd if the wiring is as it should be really (obviously you will have to look at the other pics to see the opposite end of it.)
Number 2
Is the coil
Number 3
Now this is one to note. This wire was in a chocolate block which im assuming had something to do with the alarm system.
If i put the voltmeter to this with the ignition on and the other lead to earth i get a nice 12V so im *guessing* that thisis the direct feed to the coil. Now as the wire is the same size nd colour as number 5 i connected both these up into the block and there is 12V getting to the coil on the bottom left side of the connector. All the wires on the coil plug (when plugged in) now get a 12V feed when the ignition is on. SO just to clarify the small black wire is the feed as far as im aware.
Number 4
Header tank coolant hose to top of rad.
Number 5
Now this is the wire that comes out of the connector that connects to the coil (Number 2) It has been snipped and USED to go in to the same chololate block as the live feed, however they were not in the same tunnel i.e. there were 2 chocolate blocks all togeather. As stated above this wire + wire number 3 are now connected up.
Picture 2
Now this is a picture of the connector that connects to the coil, the green wire goes into a loom near the passengerside headlamp which as far as i can tell is for the rev counter and thus needs no more attention. The rev counter worked fine when the car used to be running.
The wire top right is the one decribed in Picture 1 as number 5.
The two brown/red cables coming out of the same port - One goes down to a unit attached to the passengerside wing but changes the wire size and colour in the block shown in the picture below. The other wire from this goes straight to the dizzy. When the ignition is on both of these have 12V running through them. One directly to the bottom of the dizzy housing and the other to the small seimens black box cant quite fathom out what this is but from out of the box comes 3 other wires which go to another connector which also has 12V on each cable. From the connector 3 more wires run to the dizzy housing as the other previously stated along with the cable bottom left.
Picture 3
This is a picture of the inline connector as described above where the wire changes from the red/brown wire to the black wire which goes to the unit below on the passenger side wing. There is 12V here too. The black connector on the right is the coil connector
Picture 4
This is simply a picture of the two cables that run from the coil connector directly to the dizzy.
Anyway. I feel like i have 2 issues here, actually getting the car started. Secondly is that im really worried about drowning the carbs and engine with petrol! Any help is much appreciated
Alarm system
After working on it today, i have comepletley ripped out the alarm system, im unsure wether it was just an alarm or an immobaliser as well is i had never seen it working so i took the whole lot out. Its made no difference to the problem.
The only thing i can think of is that the battery is pretty flat now but will still crank the engine however i dont know if it would have enough voltage to allow the coil to excite the HT side of the ignition system. I would have thought honestly that the low batt wouldnt really stop this so im just clutching at straws really.
Any ideas or help is much apprectiated
Andy
Second Post:
Anyway.
Its not that! the problem is still there. All the way across the Low Tension circuit, at the coil, the idle stabiliser control unit and then onto the distributor i get 12V all the way and even at the contact points inside the distributor i get 12V at all them too.
The only place i dont get 12V is at the vacuum switch which is located on the top of the distributor housing this receives 6.23V and is fed from the idle stabiliser control unit by 2 wires: a brown and white/brown wire. This switch reads 4-6 ohms when it receives a 12V supply but with no supply it reads as an open circuit.
Ive gone through the wiring diagram in the haynes manual and everything checks out including the wire colours going to their specified locations.
The only thing i thought it might be was the vacuum switch
The continuity reading across the coil is within acceptable resistance (0.6 ohms) Haynes allows 0.6-0.9 ohms. So i'm relatively happy that the coil is in good working order.
The spark plugs are fitted and tourqued up to 15 lbft as recommended.
The HT leads are fitted in the correct order via haynes diagram
Now i took readings for continuity across the HT leads - the results are as follows and displayed starting from lead 1 & the spark plug closest to the camshaft housing which is the left hand side:
Lead 1 12.3 K ohms - slightly struggled to get this reading
Lead 2 11.4 K ohms - Easily got this reading
Lead 3 9.78 K ohms - Again little issue with getting this reading
Lead 4 10.36 K ohms - And again very little problems with this
The HT lead from the coil to the dizzy cap read:
11.44 K ohms.
All these readings look relatively similar, ive posted them as i was hoping if someone could tell me if they were acceptable resistances as haynes doesnt give me a figure to compare against.
For good luck ive even checked all the fuses in the car and they are all ok and are the specified values.
Which now leaves me thinking that the HT lead from the coil to the distributor is faulty as there is no spark when held to the engine casing upon a crank ( However the Ohm readings are similar to the other HT leads).
Or i've either ripped out a cable from the low tension side of the ignition circuit (which is also strange because the voltage is at each point it should be)
The HT leads need replacing but again the resistance of them all is very similar which suggests that they are OK
Something within the distributor could be faulty. However there is no spark coming from the coil ( which then suggests that the coil is faulty) - Again the coil reads within the resistance allowances stated in haynes.
Really would appreciate any help guys because if i dont fix it my mum is going to be really really ****ed off that i wont be home for christmas thats all!