Hello,

I know that there are a few similar problems but I wasn't able to solve it.

I got an overfuel on cylinder 3 then checked and replaced TDC sensor. Verified gap on the four plot. Between 0.6 and 1mm.
Now I have an overfuel on cylinder 1 and 2, fuel is basicaly unburned the spark is full of fuel. Cylinder 3 and 4 make spark plug totaly black so overfuel also.

The spark cable, spark plug, and so is new.

If I run the yb N/A everything is ok. Smooth running, idle stable, no problem to rev. But as soon as I put all the air hoses back. The idle is not that good, rev is almost impossible, alot of backfire.

Anyone here have got thoses problems and can give me a hint ?


Overfuel problems from right to left cylinder 1 to 4

Here is a quick video of the engine running:
Thanks!

 

........did you tried to check the vacuum pipes for the map sensor...or el connectors to the sensor

 

I didn't tried the look at them yet. I'll try in a couple of hours.
The connection to map sensor is ok. I was about to check if I didn't broke it as it is very fragile.

For more information I removed the head because I was belting the exhaust cam. I noticed that the last machining got my cylinder head 'off ribs' (not sure about it as I'm not english ).
So I took a thicker cylinder head gasket to get back to the original cylinder height and also cylinder block height as my pistons protruding from the block.

Before this operation the engine runned smooth except the noise of the bent cam.

 

Usually overfueling is caused by duf map sensor or even the ect blue sensor yet it can be load of things....try also pressure test of the vacuum pipes,maybe there is a leak somewhere...and check injectors..try cleaning them with ultrasonic.....it is time consuming but you will get it eventually..fongers crossed.......

 

I see I will check this all. Injectors might not ne able to be cleaned asap due to lockdown here but I will do them anyways event if they are not the source of the problem.

Thanks you for the hints

 

Well I checked the vaccum pipes of the map sensor. There was something blocked inside. A bee might have come during the summer..
I checked some other pipes that were left like this one but nothing in them.

I'll try to get more time to work on it tomorrow the next step is to reset the ignition timing. I moved it a bit and feel like something is not good about it.

Here comes a video of tonight running I had to go full throttle at first to get the engine rev but then it was responding to my throttle hit even if it was some small. So I will see the end soon I hope!
The spark are the same as before. Still I am almost sure that the cylinder 2 has no fuel on the spark plug when I look at it. The cylinder 1 is still full of fuel and 3-4 are totally black.

 

To keep you guys aware I moved a few degres the ignition timing to get the mark more between the "plots" of the distributor rotor arm.
Also, I put up my old ignition lead (3 of the 4 the last one as damaged) and I run prefect on the 3 cylinder that got the old leads.

So I am waiting the 1rst December to get a new set identical to my old Lead set and cross finger to get everything ok

 

Hello guys,

The new new leads it is way better but when I am trying to rev it run on 3 cylinders the 1rst one overfuel I don't understand why...

 

Just seen video,it is really bad...what ecu are you using L8?....you sure that all is aligned when you set the piston no 1 in tdc..all markings,cam pulleys,dizzy and crank pulley?

 

Thank you for your reply, I think I am using L8 as the car was made in 1991.
Everything is aligned when I set the piston 1 in TDC. Still she make noize from time to time. Someday the almost doesn't and some other it is really pushing hard, it depends on the weather I think. Well I don't drive it but some start to test things.

The test I made previously where with a dead battery she didn't past last winter it seems, but with the new battery and the new leads the idle is smooth. Some variations up mostly but as the starter is on I don't really think it is an issue. Only accelerating make the car running on 3 cylinders.

I noticed that my alternator might be faulty also 12.08V when the car is running. The battery is new and ok. This week-end I will redo the alternator cable that is not in great shape and then check if I need to replace it all or just the regulator on it.
I am checking every connector and clean them even if I don't see anything because the injector have barrely 10V at their connector so it might be a cause.
During the voltage check, the 2 first injector that receive ~10V could be unplug (one by one) almost without variation of the idle but has soon as I was unplugging the 3 or 4 the engine start to graze and then shutdown. I only had the time to seen a poorly 9.70V at best.

 

...ye check the alternator as it doesnt sound that it is in good condition...it is time consuming i know...iaw software is great tool when there is an sensor issue to discover it but if you say that the alternator is playing up sure check this also.......btw you can take out also injectors and get them checked or even you can do it yourself...there are some diy on you tube just to see if they are spraying..hope you sort it out

 

Hello,
Some updates on my problem. I changed the cable of the alternator that was faulty. The alternator is in good condition.
I also sanded the 3 motor sockets to get 12V at the injectors.

But the engine slams loudly when it gets warmer so I am looking out what it is going on and I came up that I put a high pressure oil pump but didn't put an oil radiator et changed the oil grade from 10w60 to 5w50 just before having all theses troubles. So is it possible that my oil pressure is too high and make the engine run bad?

I am going to replace the pump by a standard. Maybe get back to 10w60 and check/change my connecting rod bearings and crankshaft bearings as my oil is currently contaminated by fuel even I only started the engine, it's maybe better to be sure that they aren't hurt.
Is a too high pressure deadly for the hydraulics tappet? Shall I change them again by new ones? I changed them in decembre and they haven't done a mile yet.

 

Hello,

So the overfuel problem is solved but I still don't find the really bad sound I hear from the top of the engine (I think).
Here is a video:

Lately I changed the fuel regulator and I ordered the camshaft bearings as it sounds a bit like a bearing...

Anyone have an idea?

 

I would say at sound is coming from hydraulic lifters. Have you check oil pressure? Also bad timing can cause "ticking" sound.

Oil pressure shall be with IDLE:
cold about 65-70psi
hot about 25-30psi

Is this engine freshly build?

 

I put an oil sensor on the block with the oil switch it says 4.15b (approx. 60.19psi) at cold. With that sound I do not let the engine warm up.

The engine has been rebuilt 3 years ago and ran a bit less than 6000miles. I ran into trouble after a little trip I comes that the engine block has cracked at the cylinder head bolts. So I went with 6 studs about 1 year ago and 185 miles before I have a camshaft stud who decide to unscrew. I didn't had this bad sound before. Just when the camshaft were bend. I bought a new one that is ok.
Since then I didn't really took the time to finish to repair it.
I downgraded my oil pump from a high pressure one to a original one.

The timing is perfect. I usualy have some trouble to get the camshaft perfectly aligned but I managed to do it this time.
I will try to check if there is enough oil spray in the head by the oil feed if by any bad chance there is a clogged oil line.