Capri pinto problems

Isambard

My timing belt broke and I'm trying to fit a new one to see if it will run/is damaged

I'm out of ideas, anyone help?

The belt is on and the crank pulley is set at TDC with the camshaft pulley set on the "moving mountain". Spark at the plugs, lots of petrol by the smell of it...not running not even trying to run.

I've set the distributer so that the rotor arm is pointed at no1 plug lead when set at 6 to 8 degrees BTDC.

It all looks correct to me but I never did this before so I may be missing something obvious. (or maybe the engine if fubar,? )

All looks OK to the uninitiated under the camcover, all the valve seem to be moving.

(1.6 auto)

Wibbs

Isambard wrote: »

My timing belt broke and I'm trying to fit a new one to see if it will run/is damaged

IIRC(and I had one back in the day) the Pinto is a non interference engine so valves shouldn't meet pistons when a belt breaks.

Isambard

then why wont it run?

(afaik the 1.6 is interference and the 2.0 isn't but many say differently so the only way I can know is to try and run it or take off the head I guess which really would be uncharted territory for me)

gctest50

If the cam timing is correct, do a compression test

If the compression test is not good, do a leakdown test

blackbox

Isambard wrote: »

then why wont it run?

(afaik the 1.6 is interference and the 2.0 isn't but many say differently so the only way I can know is to try and run it or take off the head I guess which really would be uncharted territory for me)

Before you go as far as removing the head, you should do a compression test.

Isambard

OK, that's beyond my capabilities. What would it show? that valves were not opening or closing when they should?

It's a relatively low mileage engine so I'm keen to rescue it and don't mind getting the valves sorted if bent, (and get unleaded converted at the same time) but I'm trying to eliminate other possibilities by making sure the new belt is fitted right etc.

Mech1

Read this for ideas: http://www.fordcapriforum.com/forum/viewtopic.php?f=13&t=33577&sid=9d37ca85241ccac2bd94cdc4978f09c3

Pete67

The camshaft turns at half the crankshaft speed so make sure the timing is correct and the spark occurs at the top of the compression stroke and not the top of the exhaust stroke.

When the rotor is pointing at number 1 plug lead, both inlet and exhaust valves on number 1 cylinder should be closed.

Isambard

Pete67 wrote: »

The camshaft turns at half the crankshaft speed so make sure the timing is correct and the spark occurs at the top of the compression stroke and not the top of the exhaust stroke.

When the rotor is pointing at number 1 plug lead, both inlet and exhaust valves on number 1 cylinder should be closed.

I'm assuming if the timing belt is on both marks, then it must be correct. Are you saying that the camshaft could be 360 degrees out? In which case if I took off the belt from the camshaft pulley and revolved the pulley one turn would it then be correct? There was nothing in the Haynes manual to suggest doing anything else but line up the two marks. When the valves are shut would the springs be compressed or uncompressed? (I'm pretty out of my depth you might guess....)

Help much appreciated everyone

or would it be the dis 180 out?

Pete67

Yes, camshaft could be 360 degrees out. The valves are closed when the springs are not compressed, you should be able to move or rock the rockers slightly if the valve is closed.

Isambard

OK I'll try that tomorrow....can't really get my head round it though..... won't it be just the same if I revolve the camshaft 360 degrees?

Pete67

Sorry, yes you are right of course, I didn't think it through properly. Just turn the engine over by hand so that both valves are closed on the number 1 cylinder when the crank and cam pulleys are on their timing marks, and line the rotor up with no 1 plug lead and it should start.

jca

Ok, here's what you need to do to rule out timing issues. Turn the engine so that it's on the timing mark on the crankshaft pulley, it could be ready to fire on either cylinder no1 or cylinder no4. The cylinder with no spring pressure on both valves is the cylinder ready to fire the other cylinder will have both valves on the overlap changing from exhaust to inlet both springs will be compressed. Take off the distributor cap and the rotor arm should be pointing to the segment for the cylinder ready to fire, I'd say it's pointing to the wrong cylinder, if so you can bodge it and move the leads around the distributor or remove the belt and re-time it which is easy enough to do on that engine.

Isambard

as far as I can see both valves on no1 are closed when the timing marks are lined up and the rotor is pointed at No1.

what do you mean by taking the belt off and re-timing it? I've already done this putting the belt on.


If as I suspect a valve (or more) might be bent, would that prevent it firing? maybe all the vlaves are bent and none are opening/closing? how can I tell?

dooroy

Remove the 4 plugs to make the engine easier to turn.
I think you should be able to see the inlet and exhaust valves through the oil filler - if not you may have to remove rocker cover.
Then begin to turn the engine clockwise .
Watch for the inlet valve on no. 1 cylinder to open and then close.
When it has closed continue to turn the engine and watch the timing mark on the crank pulley as it approaches TDC . You can also check (through the plug hole) when the marks align that you can see No. 1 piston at the top of its stroke.
Now remove distributor cap and see if the rotor is pointing at the lead for no. 1 plug . If it is the timing is OK.
If not you could move no.1 lead to whichever position the rotor is pointing at - and then reposition the rest of the leads according to firing order.
Even if there are valves bent you should still get a spark.
Hope this helps.

Isambard

"rocker" cover already off. No 1 inlet and exhaust cams are both pointed outwards rather than down when "on the marks", so the valves should be closed. Rotor is pointed at no1 lead. I am getting a spark.

I can't fathom why I'm not getting any sign of it firing. The plugs are dry , I'm thinking the valves can't open to admit fuel, but all 4 of them? is that likely?

I'll check the piston stroke is at the top on No1 as it something I haven't done and worth a try to check.

I did try reversing the dis cap and got a back fire fwiw.

jca

Try throwing a drop of petrol down the carb that might give it some encouragement. Does it sound like it has compression when on the starter?

Mech1

Backfire means you got spark and fuel.
timing must be off, go back to basics, set up valve timing on marks cylinder 1 TDC on mark and cam cylinder 1 valves closed springs not depressed on its mark.

check firing order and direction of rotor arm rotation and ensure rotor pointing at cyl 1 and try again.

basic compression can be tested with all plugs out wind engine over and put rour finger over (not in) each plug hole it should push air past your finger.

dooroy

'I did try reversing the dis cap and got a back fire fwiw.'

Do you mean you rotated the distributor clockwise or anti clockwise - as usually the distributor cap will fit in one position only .
I presume you are using the same distributor cap as was there when engine was running ?
As mech 1 says if you got a backfire then there must be some fuel reaching the cylinders.
What kind of carb is fitted ?
Is the choke working as it should - choke flap across when you look down ?

Isambard

have a spark.
smells like I have fuel. Plugs not soaked.
No1 piston at top when on timing marks. rotor pointing to lead one 6 to 8 degrees BTDC.
both timing marks are spot on.

Lack of compression would indicate what?
can I check if the valves are actually opening ?
Is it likely all four valves could be bent? You'd think it would try to fire otherwise.

Ordered new plugs points and condenser but I doubt that will make a difference.

Mech1

If the valves are bent they will be stuck open, so no compression possible on that cylinder.

If you can see the top of each valve, are they all coming upwards to the same height? (as you rotate the crank)

Mech1

The tappet clearance on any bent valve will be much to big, look up how to check tappet clearance.

Isambard

I think that must be the case.... :-(

Mech1

http://www.godspeed.me/forums/viewtopic.php?f=14&t=735

dont tighten any tappet clearances, you will just do more damage.

Pete67

It's easy to check for cylinder compression if you can get a hold of a basic compression tester like this one, remove the spark plugs, and screw the tester hose into each cylinder in turn, and spin the engine briefly on the starter. You should see a pressure reading of approx 150 psi or greater for each cylinder. If there valves are bent / stuck, there will be no compression.

dooroy

If you have the plugs out and the rocker cover off you can turn the engine easily enough and observe the valves in action.
Bent valves will stick open - the cam will open them but the valve spring will not close them again. This will be obvious enough as the valve will not 'follow' the cam as it were.
Unlikely that there is a bent valve in each cylinder so it should fire on the 'good' cylinder(s) anyway.
I presume you checked the action of the valves leading up to TDC - the piston reaches TDC twice during the 4 strokes of the cycle. The valves will let you know if the piston is up on the compression stroke or exhaust.
It would seem the SOHC 1.6 is considered an 'interference' engine - though it seems that the speed of the engine when it failed may have some effect on the amount of damage ,if any ( from reading up on Google a little ).

crosshair1

Have you lined up the distributor timing mark when you aligned tdc and the camshaft marks?
The standard 1.6 pinto will definitely not cause valve damage, if its a high lift or 2.0 cam it may.

Isambard

all the springs are compressing when the camshaft is turned and all of them are returning after the cam has passed. There is clearance between the cam and the cam follower but not excessive, in fact if anything I'd judge they are a little tight.

where does that leave me? does the spring uncompressing indicate that the valve is shutting? would the spring stay compressed f the valve was stuck open?

I'll have to get hold of a compression tester , it's awkward to use the finger over the hole method as I'm here on my own most of the time and don't have 6 foot arms to turn the key :-).

crosshair1

then leave the plugs in and you should feel 4 distinct compressions as you manually rotate the crankshaft 2 turns

Isambard

I'm pretty sure it was like that but I'll stick em back in and check.

b318isp

crosshair1 wrote: »

Have you lined up the distributor timing mark when you aligned tdc and the camshaft marks?

This. If valve timing is right, and you have obvious fuel & spark, then check your ignition timing is right.

I'd err on having it a little too retarded, rather than too advanced. Once running, you can strobe it for more accuracy.

...and don't forget choke, assuming standard carb.