I think I bought a lemon.....

WildWilly said:
No. 1, timing on the distributor is off enough to stop her from starting, No. 2, possible broken camshaft and the valves aren't opening and closing when they should. If anyone else has any ideas, please pitch in. Thanks again to all....
Click to expand...

Foreign object ingested into the motor? Something holding an intake valve open would produce that fire back through the carb.

(I once took the air cleaner cover off of an X1/9 when we were chasing a bad idle problem... One of the studs that secure the air cleaner to the top of the carb was missng... And to our unmitigated horror we found it wedged into the primary venturi:shock:)
 
one more idea....

based on another thread, I switched to high test gas this week. There are only 30 miles on the clock with the new gas. Due to there being 10% ethanol in the regular gas here in Ontario, it was suggested that using the premium gas (91 octane, 0% ethanol) would probably be better. Is there any chance that this change in octane is enough to through the timing off and she won't start? Thinking that for the first 15 miles or so of the tank, I was using up the last bit of the old gas and once she got running totally on the new gas she didn't like it. Just a thought. We're away for the weekend, so more testing on Monday night.
 
Lots of top end noise and it was running.... sound a bit like a diesel?

Check the cam gear. that vintage of engine came with a phenolic plastic type gear with a metal insert where it attaches to the camshaft... the insert works loose, make a racket, causes a distinct loss in performance, can break loose and alter the cam timing... but snaggs again and can look OK as the cam still rotates.

If the cam gear is sintered steel or cast iron, forget the above diagnosis.

leak down test is the DEFINATIVE test for engine diagnosis, if you have a source of compressed air (you really need about 90psi to do it well) as the air can only go

past the rings
past the valves
or past the head gasket

and each gives a unique result, so there's no guessing.

SteveC
 
WildWilly said:
Is there any chance that this change in octane is enough to through the timing off and she won't start?
Click to expand...

Unlikely unless your new gas was seriously fouled and contaminated. In these days of 10% ethanol and ubiquitous fuel injection, I've gotten more tanks of bad gas than I like to think about and the effects have always shown up within a mile or so.

Also wouldn't explain the top-end noise and the exciting backfires....
 
some added thoughts after my observations last night.

clean engine bay and clean car overall so it appears well sorted.

- the cam is rotating fine, we didn't have a compression tester, but the thumb over cylinder #4 spark plug is producing sufficient compression. if #4 is rotating they all have to be rotating.

- the timing belt assembly looks to have proper tension and no obvious signs of failure or impending failure. I did note however that the cam belt was actually get close to the edge of the cam gear and was actually an 1/16th - 1/8" hanging over.

- I really want to rip that carb off as it just doesn't belong on this car. that's a personal thing. should maybe be addressed after it gets running again.

- all visible hard timing marks appear to be lining up properly and match ignition timing at cyl #4 at TDC.

- there is nothing abnormally audible in the valve train when cranking the motor over, however Willy did mention that now the car cranks over a lot faster then before. That leads me to think there is a loss compression is some cylinders if there happened to be an possible interference or it dropped a valve.

- the engine is receiving good spark at the plugs, but the timing could be way out now some how (cam jumped a tooth or something in the dizzy) visual inspection seemed like all was in "range" though

I wasn't there when the problem arose, but my suspicion leads me to 3 or 4 possible outcomes

- bent or dropped intake valve causing loss of compression and now apparent back fire when starting. (lets hope not, compression test will confirm)

- ignition timing perhaps somehow shifted dramatically

- carb has some fuel delivery issues that are new or something is/was seriously wrong with the fuel that went in it.

oh yes, and there's the mysterious electrical gremlin that shut everything down as well, possible that it's not related at all, but something to not forget.
 
Many thanks....

for coming out Andrew. I'm feeling a little better today about it all. The compression test next week will tell us plenty and if we have to we can pull the cam cover and see what's going on. Slow and streaky wins the race. Just hope its also cheap and cheerful:)
 
Reply

Hey Willy. In an earlier thread you said you had a compression tester (that you knew how to use previously on your motorcycle) and that you just performed a compression test on your X with the result of no compression.....but then you and Hojo said today that you had no compression tester and would have to get one next week ??

You say all the cam timing marks align properly, and that you are getting a spark (and getting a spark at about the right time if the ignition rotor is pointing at #4 terminal). And that there is no (or little) compression but backfiring.

At the risk of repeating myself, it would appear the most likely scenario is that the cam itself is somehow out of phase. Due to either a sheared dowel , or, as Steve suggested, the cam pulley itself shifting around.

Either can easily be spotted by simply removing the valve cover (with the cam timing marks all aligned) and looking at the position of the #4 cam lobes.

Good luck, Doug
 
I concur with Doug's suggestion, please confirm that the cam itself is turning.

If it is, try the thumb test on the rest of the cylinders.
That should narrow down the possibilities significantly.

It's beginning to sound like belt valves in one or two cylinders, but that is simply a guess without sufficient diagnostic data.
 
I would think then some of that reasoning could possibly explain the timing belt shifting along the grooves on the cam gear.

I never really thought the actual cam could shift like that, that's interesting and very plausible.

I agree this should be the next thing checked.
 
While you're borrowing/renting/buying a compression tester, you should also look into getting a timing light. You'll probably need one when you find the source of you're problem and need to verify ignition timing.
 
Reply.

Hi Andrew. What could (well possibly) have happened goes like this:

The cam pulley is bolted to the nose of the camshaft with a single bolt in the middle. There is a small dowel offset in the nose of the cam that fits into a hole in the cam pulley. Thus they can only be bolted together in one position. Proper tightening of the bolt clamps the two together firmly so they become one unit.

I am sure the person rebuilding the engine removed the cam pulley in order to change the cam seal. Now suppose that.....perhaps he didn't torque the bolt properly. Then the only thing to prevent the two pieces from not turning independently was the small dowel. Eventually the dowel could shear and the cam pulley would turn , but the cam wouldn't. BUT, when this happened, the clockwise motion of the timing belt and pulley would now tighten the bolt to the point where cam and pulley would once again turn as one .....but by now the cam would no longer be aligned with the dowel and the cam timing would be all wrong.

IF - and this is a big IF - this happened, the cam would still turn with the belt, AND all the timing marks on the crank and cam pulleys and pointers WOULD still align perfectly. And leave you scratching your head as to why the engine had no compression......of course you would have no compression if a valve was still open when the piston came up...

Steve's theory would have exactly the same result.

Both theories would match your symptoms.

Probable: no - but possible: yes......i have seen it happen before.

But super easy to check. Just align the cam timing marks and yank the valve cover - that's pretty easy - and look at the #4 cam lobes. You will know right away.....
 
I'm not sure what the hesitation is pulling the cam cover and looking. Is there more on your year to pull than just the accelerator cable and 6 10mm nuts? If the motor is recently rebuilt you probably won't even have to replace the gasket.
 
Pulling the cam cover and doing a quick lash check will also confirm bent valves... instead of 0.3/0,4mm of clearance you will have more like 3 or 4mm of clearance.

SteveC
 
Intermission...

I just wanted to make a comment as a new Fiat X19 owner myself. About a month ago I was driving along, happy as a pig in poop. As I remember I had a small blip in the clutch, but no audible noise as you had experienced and then the result was a fast turning over sound when I tried to restart the car, indicating there was no compression. That is a good compression test as it is, turning over the engine, and finding it is whirring around like there is no tomorrow means you have no compression in my mind.

Although my issues were more obvious than yours, my timing belt was stripped.

The best thing I did at that point was to take the cam cover off and invited Doug over on the weekend. We measured the gap and found some valves were about normal and others you could drive a freight train through them.

I also had trouble finding the timing marks. I found the crank mark burried under a layer of rust and dust, with a good small flashlight and a mirror. I quickly borrowed my wifes white nailpolish and then proceeded to lose it in the shuffle. (This was the most expensive part of the diagnostic). Doug helped me find the cam timing mark which was located on the opposite side. When you stand on the drivers side and look at the cam pulley from the back side, you will see a pointer, an upside down triangle that is part of the mounting bracket for the yellow cover. Then we bumped the car forward in gear, until the small mark lined up with the inverted triangle.

I, Similar to you, was disheartened. I had just ordered complete rear brakes and a master cylinder for the car and thought I had all the "half-truths" when buying a used car, in hand. My wife in her ultimate wisdom said to me, "how could you lose my nailpolish you a-hole!" No she did not, LOL that was just a joke. She said, "well you GOT the car so you could work on it, and now you have something to work on!"

She was right! So I got busy with the spanners (wheeler dealer) and on sunday removed the carb, intake manifold and cam box, all the fasteners went in one container for that. On monday (it was a long weekend) I removed the cylinder head and found my bent exhaust valves and one valve completely broken. Back in December I bought myself a socket set. I waited until they went on sale and got a complete SAE and Metric set from 4mm to 22mm that included the spark plug sockets, I bought a large hex set for the oil drain plug, and a big 26mm with a long bar and a good multi-meter, and a set of feeler guages, oh and a vacuum guage all for under $200. I think you can do most things on this car with that. A few weeks ago I got fancy and bought a Vernier caliper and a vacuum pump to bleed brakes for $50.

I took my carb to get it rebuilt because it was off anyways, this will be 2-250 by the time it is done. I got a complete set of valves, gasket set and the screws to close off the air ports on the side of the cylinder head for $150 shipped to Canada.

Now the issue I have is to remove two broken studs for the exhaust manifold, which you should not have this problem as the engine was rebuilt 2 years ago and should have new studs. I was waiting for a friend to remove them but he may be too busy, I am blessed that I have a good machinist in the family to help me clean this up next week so I can take the cylinder head to an automotive machinist to do his magic. I am estimating $500 for that.

Once I get the head back I will bolt it all back together.

In the meantime, I have taken the distributor apart, found a floating washer in the bowl, and unmatching springs on the advance, so I cleaned all that up and removed a layer of dirt and oil out of the engine compartment and feel that I know much more about what is going on with this car than I did before. And that is a good feeling and a sense of security to understand this car and how it works and to make sure it is working properly. And to boot, the net effect was not that expensive. In fact, I think I took the most expensive route to get there and I am happy to do it, because I am learning something. So do not be disheartened by it all, it really is not complicated. It is all easy to do if you have a feel for it and know which way to turn a wrench!

Cheers,
M
 
Yeah, my popcorn has gone stale waiting to hear what they found when checking the cam lobes relative to the gear. Then I remembered the OP said he was away for the weekend :(
 
I think Willy will be tackling this sometime next week so keep it in the fridge until then.

it's a shame if that's indeed what has happened to the cam/cam pulley because that's points to a human mistake in the rebuild process.

I'm interested in the outcome myself because it'll be a first hand learning experience for me to learn from.
 
I'm back...

Hi guys, Just got back from the weekend away. Tomorrow afternoon will be running the compression test. Did that on #3 last week, but got nothing, was thinking my tester was busted. Will try again tomorrow on the other cylinders. If they all read nothing on the gauge, time for a new tester. The thumb test showed a decent amount of compression on #4. Once I report that result, the cam cover will come off and we'll see whats inside. I will take lots of pictures so you can all pipe in on what might ne the issue. Really hoping the head doesn't have to come off, but it is what it is now. At the moment, sucks to be me:)
 
It Doesn't Really Suck...

Look at it this way, by the time you get her up and running, you will have gained enough knowledge about your car to give you a level of confidence and understanding that will allow you to drive her in complete confidence and enjoyment.

And you will know you are not alone in your quest for X-itement :thumbsup:
 
Cam pulley nut....

You're post got me to thinking. Something that I noticed when doing all the different things. When I pulled the cam pulley cover off, in my quest to be lazy I thought, let me get a wrench and try and turn the pulley by putting a wrench on the cam pulley bolt. You know, save myself the trouble of jacking her up and using the 4th gear method. The cam pulley bolt was not very tight at all, so I gave it a turn to tighten it up. That starts to line up a little with what you were saying. This afternoon the compression will be checked and the cover comes up with lots of pictures. More soon......
 
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