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Paul Lewis

I was reading some of the old posts on this site a saw that a couple of guys had suffered from running problems with their 16 valve 33's when the engine was first started but as soon as it had run for a few minutes the problem dissappeared and the cars ran fine. My M reg 16 valve has the same problem and despite taking it to three different garages the intermittant problem is still there. Two of these were Alfa specialists Allitalia in Wrexham and Automeo in Bristol. My car has done 64,000 and recently has had the following done:-

New head gaskets
New cam belts
New oil and filter
New cat and lambda sensor fitted
The plugs are new platinum ones and the car has had new high quality HT leads from Clovertech.
I have also had the coil, the temperature sensors and the distributor replaced. Both the throttle bodies and the mixture were all set up by Les Dufty at Automeo (and he is an absolute expert on boxer engines!). Unfortunately I am in North Wales and Bristol is a hell of a way to go for him to find this intermittant fault. After he last had the car for two hours he made it run so much better but the fault is still there.

Basically when I start the car and it has been standing for a while the engine runs unevenly and there is a slight backfire around 2000 revs. Once the engine warms up sufficiently, the problem dissappears. The other problem is that it doesn't seem to happen every time. Could it be a fuelling problem? I have used injector cleaner regularly. It is really beginning to piss me off that I can't sort the problem out. If I start the car when it has been standing for some time it splutters down the road, jerking along until after a mile or so it seems to be alright. Yet if if then stop the engine and pop in the shops or petrol station for a couple of minutes and start it again it is absolutely fine. Has anyone had this problem with a 16 valve? Also when 16 valves are totally set up correctly are they still jerky to drive on the throttle around town or am I expecting too much? My only other 16 valve was a P4 but I think that was chipped as it was extremely smooth.
CAN ANY OF YOU OUT THERE SHED ANY LIGHT ON MY PROBLEM AS I CAN'T KEEP SENDING THE CAR TO SPECIALISTS AS IT IS COSTING ME A FORTUNE?? (£45 per hour last time!!)
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Currently own a late 33 16 Valve (M reg) in Silver, with P4 alloys and superspint back box.
I live out in the sticks with not an Alfa specialist for miles around!!

Paul Lewis · Posted: Tue Jul 20, 2004 10:30 pm Post subject: Just an afterthought!

Referring to my last post, I forgot to mention that I have a noisy tappet on the front right hand side of the engine (looking from behine the steering wheel) and it is particularly noticable when the car is started from cold. Could this be causing the problem..and maybe when the car has run a little it clears itself. When the engine is warm you cannot hear it. If this is the problem how can I cure it??
Thanks Paul.
_________________
Currently own a late 33 16 Valve (M reg) in Silver, with P4 alloys and superspint back box.
I live out in the sticks with not an Alfa specialist for miles around!!

bobbber · Posted: Wed Jul 21, 2004 9:57 am Post subject:

Ticking tappets?
Can't pull away, car almost stalls?

These things go away when the car is warm?

Probably lack of oil in the hydraulic tappets resulting in excess crankcase pressure.

Does this sound right?

Do you have an oil filter with 'non-return' valve?

Have you cleaned the crankcase breather recently?

Bob
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Fiat Bravo 165 Sport

Paul (not logged in) · Guest

Hi Bobber. The symptoms you describe are very similar to problem that my car seems to have. Stuttering and alsmost stalling when engine is cold. I have checked the filter and it is a black Lancia original equipment one. It was fitted by Allitalia when the car was in for it's head gaskets and cambelts to be done. I did the oil change before that and I got a fliter from an Alfa dealer and it was the same a black Lancia one..so it must be the right non-return valve one? As for the crankcase breather..where is it and how do I clean it out? The car currently has Agip 10w/40 semi synthetic oil in it, but Les dufty at Automeo said I should put 10w/60 Racing synthetic in the engine and that would cure the noisy tappets. What do you reckon?

Thanks Paul.

Guest · Posted: Wed Jul 21, 2004 1:54 pm Post subject:

I tried some 15W/50 - tapping and 'choking' worsened.
Then put some 5W/30 - tapping and 'choking' worsened further!!! Laughing

My understanding is that (and someone smartass will correct me if not!) excess crankcase pressure stops the oil flowing into the hydraulic tappet. A hydraulic tappet is like two stacked thimbles - the oil goes in between and takes up the slack.

Yes, take a look at the crankcase breather. It's located on the top of the oil filler pipe. Take the oil ('olio') cap off - there's a screw inside. Undoing this screw separates the oil tube into two, allowing you to remove the top section. The 'breathing' takes place through the corragated filter in the section - and this probably needs cleaning (put it in petrol overnight). You'll need to remove the rubber tube which goes into the top section too.

The other end of the rubber tube connects to the 'fire restriction apature' - which is like a small metal tube with a smaller hole in it - this can get clogged too. You'll probably notice it's where the rubber tube is spliced.

My guess it that the breather filter is clogged - i'd start there...

Lemmie know how it goes!!!!

Cheerz,

Bob.

Guest · Posted: Wed Jul 21, 2004 1:59 pm Post subject:

Forgot some things!!!! ---->>>> Shocked

The screw inside the oil tube is captive on my car, but I've heard might not be on others. So you'd do well to undo the screw a little and then wrap some wire around it to stop it falling down the tube when you unscrew it fully. A screw in the crankcase is exactly as it sounds! Laughing

The other thing is when replacing the breather - it only goes on one way round. There is a 'U' shaped gap in the top, and a 'V' shaped protruding notch on the top of the lower tube. This can be quite tricky to align correctly - but it does need to be correct.

Bob.

Paul (not logged in) · Guest

Thanks for the advice. I will clean out the crankcase breather tonight when I get home from work. As for the noisy tappets what is the best thing to do to sort them out. Les Dufty at Automeo suggests I use 10W/60 Fully Synthetic Racing oil, which he reckons will quieten them down and sort them out? What do you reckon?

Also is it worth putting in a product for freeing up stuck tappets - like they sell at garages??

Cheers Paul.

bobbber · Posted: Thu Jul 22, 2004 10:53 am Post subject:

I found cleaning the breather corrects the noisy tappets as it allows the oil to flow into them unopposed by excess crankcase pressure!

Bob
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Fiat Bravo 165 Sport

lesthegringo · Alfasud Joined: 23 Jul 2003 Posts: 97

Sounds to me like you have a faulty sensor on the injection system. The symptoms you describe when you first start the car sound like the engine is not getting a correct mix when cold. Are you sure it's a backfire in the exhaust, or could it be a 'spitback' in the induction?

Get someone to follow you when it happens, and see if there is black smoke from the exhaust and a strong smelll of unburnt petrol - this would indicate a rich mix. I think though that it is more likely to be a lean mix caused by the sensor reading wrong, and fooling the injection that the engine is hotter than it is - which is why the problem disappears with a hot engine.

The temperature sensors are in the throttle bodies bolted to each head, one is for the injection and the other is for the guages. The one that has a plug similar to the injector plugs. You could try cleaning the contacts first, and see if this improves the situation - it's a free check. If not, you may want to try a new sensor, they are not that expensive.

Let us know how you get on

Les

Admin · Posted: Thu Jul 22, 2004 11:39 pm Post subject:

Hi

Sounds to me like a fault with a sensor as well.

It is worth cleaning out the breather hose, and also try flushing the engine through with flushing oil.

Using thicker oil with an engine with hydraulic tappets can sometimes cause problems. The tappets can pump up, stopping the valves from closing, although this is not a problem particular to the 33 and I have not heard of any 33 owners having this problem.

All the best

Keith

Paul (not logged in) · Guest

Thanks for the advice, I have already changed one sensor which is the one located in the left-hand throttle bank as you look from inside the car. The replacement sensor was not new but came of my P4's engine, which never had this running problem. It has made no difference! Do I need to also change the sensor which screws into the right hand throttle body?? I also cleaned the crankcase breather last night, which on my late car is a plastic sealed unit which twists and locks into place at the top of the oil filler pipe. Anyway, I took it off and soaked the whole thing in petrol for a few hours and when I took it out of the petrol there was a lot of crap in there!! Refitted it to the car, but still no real difference!! I also cleaned the pipes which run from this unit to the intake manifold. Getting a bit hacked off as this problem seems incurable!! What do you think about changing to 10W/60 Agip racing oil (a snip at £7.95 a litre!!!?) The thinner oil may help??

Cheers Paul.

Admin · Posted: Sun Jul 25, 2004 12:18 pm Post subject:

Hi

There is one air temperature sensor and one water temperature sensor and both will feed back to the ECU.

10W60 is a thicker oil, and might cause problems with the tappets. However I have not heard of people having this problem with the 33 engine but many people racing will have replaced the hydraulic tappets with solid ones so be careful that they are speaking from experience with an engine set up the same as yours.

I would also possibly be tempted to get the injectors cleaned (or possibly take the ones off the old engine if you still have it, get those cleaned and then just swap them over).

All the best

Keith

Paul (not logged in) · Guest

Hi Keith. Thanks for the advice, but you mention two sensors. I have changed the one with the blue plastic double pin connector which screws into the left hand throttle body (when viewed from within the car). Do I also need to swap over the air temparature sensor, and if so where is it located. Also, where would you recommend I send the spare injectors to for cleaning. Cheers Paul

Paul Lewis · Posted: Mon Jul 26, 2004 9:27 pm Post subject: Still having problems.

Hi All. Despite trying a few things my 16 valve still seems reluctant to run properly when the engine is cold or not fully warmed up. if it is started with a warm engine it seems to be fine. The tappets are still rattling but this seems to be an intermittant problem too as when the engine is warm they quieten down. I have cleaned out the crankcase breather and also changed the coolant temperature sensor which is located under the left hand throttle body (when viewed from within the car). I did not fit a new one but took it off my P4's engine..which never had any running problems. I have also checked the plugs (new) and HT leads (new) and cleaned all the connections. Is the air temperature sensor located inside the AFM and if so could it be that which is at fault? Would I need to get a new or s/h AFM?

The car has actually been running a bit better, but today when I left work..(car had been standing eight & a half hours) it seemed reluctant to rev and felt like there was a 'spitback' in the system. The car didn't make a loud backfire, but there was a definate 'pop' in the exhaust every time the throttle was touched. this problem cleared once the engine was warm.

If the fault is the air temperature sensor is it easily changed.
Also is it worth swapping the ECU from my P4 or will that be different as it was non-CAT? I have checked my cars service history and the ecu was sent away for checking along with the AFM a few years before I had the car.Could this be faulty? As for the throttle potentiometer, are they reliable or could that be the problem?

Any answers.....anyone?????????????????????

Cheers Paul.
_________________
Currently own a late 33 16 Valve (M reg) in Silver, with P4 alloys and superspint back box.
I live out in the sticks with not an Alfa specialist for miles around!!

lesthegringo · Alfasud Joined: 23 Jul 2003 Posts: 97

Swapping the ECU is a fairly quick way of eliminating the possibility of it being duff. If it does cure it, put the old one back in to make sure it is the ECU, and not that you have re-seated the connection pins on the connector block

Les

Tom · Guest

Hi Paul,

I have got the same problem on my 16V. I have exchanged the water-temperature sensor - no success. I also measured the air-temperature sensor located in AFM - seemed to be OK. I spent much time by trying to find some elektrical fault like a wrong contact in connectors, cables, etc. - no success. I also tried LED-blinking test - it didn't show any fault.

I know other people in my country (CZ) to have the same problem on their cars. IMHO it is is caused by ECU. It would be extremely useful, if you can test it by swapping the ECUs. I read somewhere, that the ECUs for cat and non-cat are the same - the only difference is in connecting a little box like relay in appropriate connector located near to ECU. This little box makes a short circuit and it lets the ECU to know, that the car has got a cat.

Regards

Tom