Volvo engine aq145a

[Steve P]

Hello All
Here we go, hopefully someone may have an answer!! Volvo engine aq145a Will not start it does crank over but no start, what we have done so far, engine stripped sent to engineering shop for inspection Cylinder block =good Cylinder head=good, rebuilt carburettors with new gaskets jets etc, fitted electronic ignition distributor, new timing belt fitted as follows, camshaft index dot lined up with camshaft cover notch intermediate shaft pulley lined up with single line on cam belt and index dot on pully same as camshaft single line on cam belt, double line on cam belt lined up on crank pulley Engine at tdc 0 deg rotor arm pointing to plug number one rotation clockwise viewed from side of engine looking at distributor cap firing order 1342 as book spec, We reset the TIMING BELT to 6deg btdc the engine did try to start however would not run and backfires. plus the only way we could any sort of run was constantly moving the throttle lever effectively using the accelerator pumps on the carbs to squirt fuel into the engine this eventually leads to engine flooding and more backfires not good, we have noticed the spark plugs are fitted with resistors "R" in the model number for spark plugs indicates resistor fitted, learn something new every day the volvo book states spark plugs with no resistor, new plugs ordered, Am i missing something set up the engine timing wrong we have now put the timing belt back to 0 tdc been told the Solex PA1 is problematic and very difficult to get correct even when new ours are old units Any help suggestions much appreciated Forgot to add new pistons rings have been fitted and bores honed compression is very good as per machine shop Thanks Steve P

 

[stelican]

Are the cylinders flooding (wet plugs)
Sorry just reread OP and you mention flooding.
Maybe distributor 180 degrees out.

 

[Steve P]

hello thanks for reply, yes plugs all wet we have noticed the spark we think is very weak maybe due to resistor spark plugs

 

[Steve P]

update we removed all plugs (all wet) spun engine over to clear cylinders there was fuel in there stinks of petrol the engine is out of the boat and we cant see any point in reinstalling until its running correctly as it not easy to work on in the boat

 

[Steve P]

Thanks for above regarding distributor 180 deg out will check and let you know

 

[steadyeddy]

+ 1 for 180 deg out

 

[VicS]

Hello All
Here we go, hopefully someone may have an answer!! Volvo engine aq145a Will not start it does crank over but no start, what we have done so far, engine stripped sent to engineering shop for inspection Cylinder block =good Cylinder head=good, rebuilt carburettors with new gaskets jets etc, fitted electronic ignition distributor, new timing belt fitted as follows, camshaft index dot lined up with camshaft cover notch intermediate shaft pulley lined up with single line on cam belt and index dot on pully same as camshaft single line on cam belt, double line on cam belt lined up on crank pulley Engine at tdc 0 deg rotor arm pointing to plug number one rotation clockwise viewed from side of engine looking at distributor cap firing order 1342 as book spec, We reset the TIMING BELT to 6deg btdc the engine did try to start however would not run and backfires. plus the only way we could any sort of run was constantly moving the throttle lever effectively using the accelerator pumps on the carbs to squirt fuel into the engine this eventually leads to engine flooding and more backfires not good, we have noticed the spark plugs are fitted with resistors "R" in the model number for spark plugs indicates resistor fitted, learn something new every day the volvo book states spark plugs with no resistor, new plugs ordered, Am i missing something set up the engine timing wrong we have now put the timing belt back to 0 tdc been told the Solex PA1 is problematic and very difficult to get correct even when new ours are old units Any help suggestions much appreciated Forgot to add new pistons rings have been fitted and bores honed compression is very good as per machine shop Thanks Steve P

I dont understand what you are doing when you say you "Reset the timing belt to 6° BTDC" or" put back to TDC"

The timing belt should be fitted with all three sprockets set to their respective timing marks and the marks on the belt.

The distributor should be fitted with no1 cylinder in its firing position ie both valves fully closed ( view the cams through the oil filler) and the crankshaft pulley on the TDC mark

Set the distributor rotor arm approx 60° clockwise from the mark on the distributor body so that when the distributor is installed the rotor arm is pointing at the mark on the body. (There may be a line on the rotor arm but I cannot see one)

Final timing must be done with the engine warmed up, vacuum hose disconnected , running at the correct idle speed, using a stroboscope and the timing scale in the belt guard.

 

[Steve P]

Hello Thanks for your comments much appreciated, as you describe above that is exactly how i timed the engine, the reason i repositioned the timing belt to 6deg btdc is i misread information regarding this engine, as the 6deg btdc is achieved with a strobe light when running and slightly moving the distributor to get the optimum running although 6deg may not be the optimun setting i just cant understand why the engine will not even attempt to start i did look at the cam lobes when checking everything the lobes are pointing away from the valves so to me that is tdc compression stroke rotor arm pointing to NO 1
Thanks Steve P

 

[Steve P]

Thanks to all for helping me with this issue, could someone explain 180deg out i understand the principle, however how easy or difficult would it be to get it 180deg out

 

[VicS]

It would could happen if you merely set no 1 cylinder to TDC before installing the distributor it could be no 4 which is in the firing position ie at tdc at the top of the compression stroke . The distributor would then be 180 ° out if you installed it with the rotor arm pointing at no1
That is why you have to check that the valves on no 1 are both fully closed Ie cams pointing upwards.

( its easier to understand than it is to explain! }

Have you set all the valve clearances correctly

Did you check the strength of the spark ... it should jump about 1cm if tested with an adjustable gap spark tester


Cannot help with the Solex carb but have you checked the float height and that the needle valve is closing properly.

 

[Steve P]

HelLo VicS I understand it is not over easy to explain i will check tomorrow the position of the cam lobes in relation to tdc No 1 cylinder The valves were set at the machine shop during the inspection if okay with admin i can attach some photographs this may help explain the issue, on the Solex carbs the float chambers on both carbs are full but not over filled to the point petrol escapes, I at plugs does look weak and i believe would struggle to jump 1cm i will do the test tomorrow and let you know the out come , the valve lobes on number one tdc are not pointing straight up more horizontil to the valve however the lobes are away from the valves suggesting both inlet and exhaust on No1 at tdc are closed Thanks again for your explanation much appreciated
Steve P

 

[QBhoy]

Sure sounds like you are 180 out.

 

[Bran]

I know it gets frustrating when you get to this stage so take a step back and check the following:
remove spark plug no 1 cylinder
open oil filler, rotate engine clockwise as viewed from front until no1 camshaft looks likes the picture below, you are looking for the two cam lobes to be pointed upwards about 60 degrees from vertical. Imagine a pair of bunnies ears as i was told as a trainee.

I would then take a long plastic ty wrap and carefully partially insert into no 1 spark plug hole and then rock the crankshaft slightly back and forwar, feeling with the Ty wrap on the top of the piston to ensure it is at its highest position. Then rotate the crankshaft slightly anticlockwise and then slowly clockwise until the piston is exactly at top dead centre, it’s highest position. Make sure not to let the Ty wrap drop into the cylinder and do not rotate the engine too far with the Ty wrap inside. The last thing you need is loosing it inside the cylinder.
once you are certain no 1 is at top dead centre check the position of the distributor rotor arm, it should be at its alignment mark and this should coincide with the ht lead going to no 1 cylinder.
next fit a spark plug to the ht lead for no1 cylinder and hold it against the block.
ignition on, undo the distributor clamp and rotate the distributor back and forward, this should produce a spark.
not 100% sure you will have enough movement on the distributor to do this but it normally works.
if you do get a spark, turn the distributor anti-clockwise, then slowly turn it clockwise until you get a spark, then lock the clamp.
this sets the timing around top dead centre.
then reinstall spark plug and give it a try.
don’t worry about setting the timing to 6 degrees before top dead centre, modern fuels means it will be different to that value.
once the engine is running slowly tweak the timing to get a smooth fast tick over.
the resistor spark plugs were used with solid core ht leads. Non resistor plugs are used with a carbon core ht lead.
if in doubt measure the resistance of the hit lead, less than 1 ohm is a solid core.
hope this helps.

 

[VicS]

I would then take a long plastic ty wrap and carefully partially insert into no 1 spark plug hole and then rock the crankshaft slightly back and forwar, feeling with the Ty wrap on the top of the piston to ensure it is at its highest position. Then rotate the crankshaft slightly anticlockwise and then slowly clockwise until the piston is exactly at top dead centre, it’s highest position. Make sure not to let the Ty wrap drop into the cylinder and do not rotate the engine too far with the Ty wrap inside. The last thing you need is loosing it inside the cylinder.

It is easier to use the mark on the crankshaft pulley

once you are certain no 1 is at top dead centre check the position of the distributor rotor arm, it should be at its alignment mark and this should coincide with the ht lead going to no 1 cylinder.
next fit a spark plug to the ht lead for no1 cylinder and hold it against the block.
ignition on, undo the distributor clamp and rotate the distributor back and forward, this should produce a spark.
not 100% sure you will have enough movement on the distributor to do this but it normally works.
if you do get a spark, turn the distributor anti-clockwise, then slowly turn it clockwise until you get a spark, then lock the clamp.
this sets the timing around top dead centre.

This will work with a points distributor but will it work with a contactless one ?

then reinstall spark plug and give it a try.
don’t worry about setting the timing to 6 degrees before top dead centre, modern fuels means it will be different to that value.
once the engine is running slowly tweak the timing to get a smooth fast tick over.
the resistor spark plugs were used with solid core ht leads. Non resistor plugs are used with a carbon core ht lead.
if in doubt measure the resistance of the hit lead, less than 1 ohm is a solid core.
hope this helps.

 

[Steve P]

Hello Bran, Thank you for your input there is a wealth of knowledge on here we are very grateful to you all for talking the time to reply, The plan today is to recheck everything especially the 180deg out as this appears to be the culprit (or me) then follow your plan as in the photograph, looking at your photo with cam lobes in that orientation , I know ours are not in the same orientation , however i will take photos before we make any changes . your comment on HT leads is interesting at present we have resistor plugs with carbon HT leads (new plugs arriving tomorrow none resistor type) I believe this will cauase a weak spark, So, im of to the garage to apply all suggestions Thanks to all
Steve P

 

[Bran]

It is easier to use the mark on the crankshaft pulley
Dont forget the engine has been stripped and reassembled, normally the crank pulley has a single key and can only be fitted one way but who knows all its history so it’s best to go back to basics.


This will work with a points distributor but will it work with a contactless one ?

Not sure that’s why I said not 100% sure as I dont know the distributor. It has worked for me on several occasions worth a try.

 

[stelican]

Just a thought but is it possible for the crankshaft pulley to be 180 out

 

[spannerman]

When you changed from points ignition to electronic did you change the coil also as they are not cross compatable, electronic ignition needs the right coil.

 

[Steve P]

Hello All, This is embarrassing !!! as above we checked everything again electronic ignition with new compatible coil checked all pulleys took belt off replaced it with all the index marking all lined up, Then took dis cap off !!!!!!! oops rotor pointing to N0 4 corrected that hooked battery up and IT LIVES started up first time the Engine will only run with pumping the the throttle linkage so an obvious problem with the twin Solex carbs My Brother (boat owner) is contemplating changing the twin carb arrangement for a WEBER conversion quite costly but everyone says the solex carbs can be troublesome The boat will be used on cannels at that limited speed No sea water use A BIG BIG thankyou to all that have helped us out its a big relief knowing the engine runs apart from the carb issue Anyone have experience of the carb conversion is it worth or having the Solex units rebuilt by a specialist (approx £150 per carb) 180deg out how did i missed that ???? embarrassing, but you guys have been brilliant
Thanks to you all Steve P

 

[Bran]

Great news, thanks for the update. Don’t be embarrassed we all make mistakes!