Car has had timing set but wont start.

roscopervis · Post by **roscopervis** » 20 Jun 2003, 20:04

Some time ago I had a minor failure of a timing belt tensioner on my 2.0 16 Xantia. The car was still running when I turned the engine off.
Due to work coomitments and other niggles, I have only just got round to getting the timing set after taking the belt off to replace the tensioner. However now when the car is turned over it makes afunny grinding noise and backfires. It sounds like bad news. Can anybody tell me what has happened?
If its gonna be expensive I might just sling it in the sea.

jeremy · Post by **jeremy** » 20 Jun 2003, 21:33

I think its trying to run backwards and the grinding noise is the starter protesting. How did you set the timing? I would strongly suggest you check itvery carefully, if necessary verify it by taking off the camshaft cover and verifying the valve opening positions.
jeremy

AndersDK · Post by **AndersDK** » 20 Jun 2003, 21:50

Since the engine was running before replacing the timing belt - there is a big chance you missed your luck on timing the new belt correctly.
This kind of problem is the genuine nightmare for any DIY'er [:(]
Problem is that if you did'nt do the job correctly at first - chances are you've mis-interpreted the instructions on indexing the engine axles - and then it's usually very hard to understand what's wrong.
Your report on the grinding noise from the cranking no-start backfiring engine is very scaring to me - sounds like the valves may have a nasty pow-wow with the pistons.
The grinding noise indicates mechanical problems in the cranking engine - something is rotten in the Kingdom of your 1.6 engine.
The backfiring points to a very bad timing offset - unburnt fuel ignited in the exhaust cycle.
Well - how to get on with the problem [?]
You need to remove the belt again & then have the engine axles indexed correctly. To do this you should have at least 2 different instruction methods - like the instruction on the belt package & the one found in Haynes. This ensures a better overall explanation of the process - covering possible missing spots in each instruction.
If you have the old Haynes on BX - then this reference for the general cambelt replacement procedure may be at help - possibly covering any dull explanation in the other instructions.
I know what you're into - totally missed my luck on timing the ignition y's ago on an old Simca1501 - despite having the manual at hand [B)]

roscopervis · Post by **roscopervis** » 21 Jun 2003, 21:48

I didn't set the timing, a mechanic did it. Its the old 2.0l 16v engine (155hp). The timing was set by lining up the three timing holes (one bottom, 2 crank) and pinning them then replacing the belt and tensioning it. The car was turned over two times by hand then checked to see if the timing holes were still lined up, they were.
Jeremy, what do you mean by saying running backwards? Is this the end of my valves? This car has become a nightmare in the last year.

algieuk · Post by **algieuk** » 22 Jun 2003, 04:03

Don't worry...a 4 stroke engine cannot run backwards, the sequence of the valves would be wrong and it would fire after sucking from the exhaust pipe and blow the air out through the inlet manifold. It does sound like you may have your cam out by 180 degrees though although so long as the peg in the flywheel wasn't removed this shouldn't have happened. It isn't something really silly like having your plug leads swapped around is it?

Dave Burns · Post by **Dave Burns** » 22 Jun 2003, 05:38

What Jeremy means I think is that the timing is far to advanced and is pushing the piston back down before its gone over TDC, turning the crank backwards momentarily.
Of course it won't actualy start and run backwards because it won't get the fuel to do it, thats not because its a 4 stroke but because it doesn't get its fuel delivered direct to the combustion chamber.
Diesels of yesteryear with inline injection pumps were buggers for it on occasion, some lorries had the air filter in the cab and thats where the exhaust came spewing out, they also went berserk, revving their nuts off and ignoring the stop lever, the only way to stop them was to deprive them of fuel, drivers used to smash the glass filter bowl or rip pipes off to achieve this during the emergency, before the engine consumed its self.
Dave

jeremy · Post by **jeremy** » 22 Jun 2003, 16:42

Thanks Dave - thats precisely what I meant but didn't put very well. Its a quite distictive and 'unhappy' noise when it happens.
jeremy

roscopervis · Post by **roscopervis** » 22 Jun 2003, 23:09

It has ignition coils so the leads can't be wrong. If the three timing holes were locked when the belt and tensioner were done, then romoved, the engine cranked twice, the holes checked to see if they line up, which the do, then start it which causes this horrible quite high pitched grinding noise, no chugging at all and a backfire every 5 seconds, then that sounds like it was done right. If its the valves, how much to fix??

alan s · Post by **alan s** » 23 Jun 2003, 03:46

I think the only way this job will ever be sorted is if you resort to basic troubleshooting principles.
Firstly & most importantly, take a compression reading on all cylinders.
They, I would hazard a guess, would read about 175 psi however, I wouldn't take that as gospel but rather look at the difference in pressures between cylinders; anything above 25 psi is cause for concern.
My initial suspicions, which I don't expect too many will race to agree with, is possibly as a result of standing idle, you may be a victim of what normally would be considered extreme coincidental bad luck, but if the car had been idle for a while is quite feasible. These are:-
Starter possibly sticking in mesh which would account for high pitched grinding noise.
Assuming that the engine concerned has hydraulic valve lifters, that there could be one or more sticking accounting for the backfiring and adding to the generally unpalatable mechanical noises. I did also have a CX Gti once that came this backfiring & rough running caper due to getting water into the air-flow meter and causing shorts.
The reason I mention the hydraulic valve lifters, is that we recently had a BX 16V motor down & during reassembly at an engine rebuild shop, were advised to "burp" the smaller piston within the actual valve lifter body as this we were told can cause them to jam in the open or shut position & cause the ngine to "run like $#!+" to quote the man [}:)][:D]
Another point where people often get caught & this may not be applicable in this case but worthy of checking is the connections on the top of the injectors. We have struck a few recently where these plugs have been disconnected & upon reconnection, the pins inside the actual plug have moved back into the plastic rather than connected properly electrically. This can either cause rough or no running depending on how far back into the plug the pins have slid or can give all the symptoms of timing being badly out through misfiring or only firing on the cylindes where the plugs have properly connected.
May be a good starting point also.
Alan S

jeremy · Post by **jeremy** » 23 Jun 2003, 03:49

Are you sure about the coils, 2 coils, 2 leads from each, each sparking every revolution I know but isn't each coil timed 180 degrees from the other?
Think about it another way - the pistons move in pairs and get a spark every time they come to TDC (well near enough). . . - Sounds to me I could get them muddled! The ones in question would be the pairs 1&2 and 3&4.
Jeremy

roscopervis · Post by **roscopervis** » 23 Jun 2003, 04:20

I am sure about the coils, they havent been touched from when it was working.
Some good points alans, will have to give that a shot. How would I cure the hydraulic lifter scenario? What is burping it? I reckon its going to a garage as soon as I recover from the funds its eaten up lately.

alan s · Post by **alan s** » 23 Jun 2003, 04:58

The "burping" is done by removing the small piston within the large, blowing out, oiling up & refitting. The lifters would have to be removed from the head to do it.
I would look at that as a last resort; I'd firstly check the injector plugs to be sure they're connecting as I feel there are more people (mechanics included) caught by this than would care to admit to it.
On most cars fitted with 2 coils, they work on a "wasted spark" system & normally, the HT leads are usually situated in such a way as to be very obvious if wrongly connected. Effectively, sparks are flying everywhere, TDC - BDC etc & timed in such a way so that the ECU does the thinking for them.
If the starter is sticking, it could be via the drive cog staying in mesh.
Alan S

Post by **RichardW** » 23 Jun 2003, 18:00

There was a guy with a BX where the woodruff key on the camshaft snapped off, so although he was merrily sticking the timing pins in, the camshaft was way out... Might be worth whipping the rocker cover off and checking the camshaft is doing what you expect it to!
Richard

alan s · Post by **alan s** » 23 Jun 2003, 18:03

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by RichardW

There was a guy with a BX where the woodruff key on the camshaft snapped off, so although he was merrily sticking the timing pins in, the camshaft was way out... Might be worth whipping the rocker cover off and checking the camshaft is doing what you expect it to!
Richard
<hr height="1" noshade id="quote"></blockquote id="quote">
"the woodruff key on the camshaft" are you sure??
Don't mean CRANKshaft by any chance??[?][?]
Alan S [;)]

Post by **RichardW** » 23 Jun 2003, 20:24

Defo camshaft, was one of the guys on the BX Q&A IIRC. Pin went in nice, but on inspection camshaft was running about 180° out. Somehow he claimed not to have any bent valves - at least the motor ran one the key was replaced and the camshaft correctly set.
Richard