hello, Would be grateful to receive help about injection problem I can't solve, which is coming back after a first occurence. I have a 512 BBi, 1982, just acquired in France, and fully restored by a well known garage in Italy one year ago (attached engine pic). I am not a skilled mechanic, mostly on injection troubleshooting. Symptome: the engine starts easily, but when hot, below 2000RPM, the accelerator doesn't respond when pressing, the engine detonates very strongly, sometimes stalls and it is very difficult, by pumping gently on the accelerator, to make it come over 2500RPM so that the engine responds normally. The car has been looked by my garage and they say that after search (fuel pressure measurements, spark plug inspection, etc) the small injection pipe to the final injector on one cylinder (#5) was plugged with scaling. Saying that during the resto, it had probably been oxidised, even if they have been beautifully dichromate plated externally. They cleaned it and was looking to function normally after this. OK, but yesterday the same syndrome came back with very strong detonations when slowing down below 2000RPM, arriving to traffic lights for instance. Maybe it could be another feeding pipe, oxidised inside, with same impact? But, thinking further to it, I can't understand how one line, or even 2 or 3, plugged with corresponding cylinders out could bring that problem. Having a power reduction yes, but not being able to accelerate, detonations and even stalls, no? And over 2500RPM it works, so? Probably there is another general problem, and not only one or more pipes plugged. I would be grateful to receive help to tell me how to proceed. Thanks a lot, Best regards, Jean-Paul Image Unavailable, Please Login .
remove the airfilters both sides and have a look at the plates in the fuel distributors. not turn on the igniton. then try to push the plate down. may be it stucks a little at the beginnig and when more open it goes easy. that would explain the problem up to 2500 rpm
Danke sehr Romano. Looks interesting, but when I start from cold the engine, the accelerator and RPM move gently up when pressing, without any apparent "hard point". Will do your recommended check this afternoon and tell you, Jean-Paul
when cold may be it works, also when cold the engine gets more fuel by the cold start injection valve. but when warm the material gets a little larger and may be then it will stuck a little? if ok then you may meassure the fuel pressure I not know how much mechanic you are? but next I would do would be to remove the injectors from the inlet manifolds and test them. but I think it is not a problem of the injectors. you have the chance to test the exhaust gases ( CO and HC )? this will tell you much also. good luck you not filled out in your profile what part of france you stay. may be near to me?
Take the point on dilatation effect. But I just checked: both sides, very smooth opening of the flaps from closed to full opening. When it happened first time my local garage reported to have checked : - the fuel pressure, OK - all the injectors, in good condition, OK - the 12 spare plugs to detect that cylinder #5 was not firing with dry plug - then, it appears that fuel was not duly arriving to the injector #5 - then deposit the small pipe from K-Jetronic center to #5 injector to discover it was plugged with oxidation scaling. maybe due to long "dry stay to O2" when restoring the car. But, again, I can't imagine that having some injector plugged, even 2 or 3, can come to the fact that engine rattles up to stall with detonations when below 2000RPM. Should be just power reduction and abnormal engine noise hearing. I am not a great mechanic (a small scissor crane at home) mostly on injection I never practiced (I have another 330 GTC and E-type S1 and MK2 Jaguars with Webers) and no lambda sensor to check the exhaust. But I wish to control the process of troubleshooting vis a vis my garage which is not so acquainted with Ferraris, to skip bullshitting. I am located in Bordeaux, and the car is not fuelled with Bordeaux wine, but if you come there will be a pleasure to open one bottle. So, let's see how to drive the troubleshooting. If you or others have an idea/experienced tis symptoms. best regards, Jean-Paul
jean paul, as always the last few years I stay during our wintertime in thailand. will come back end of mai. so if you still have trouble then I would be proud to help you and when finished drink some bordeaux. or may be when have problems drink this during thinking what could it be when the engine is cold you can drive without any problem? how long? what water temperature the gauge shows? what will happen when you for example go 10 or more km with over 2500 rpm and slow down then? what about idle then? have a strope light to check all igniton wires if there is a spark? so best would be to check the injectors first for pressure and spray pattern. first of all eliminate things and then try to find out if it will be an ignition or an injection problem
Thanks Romano, Good to stay in Thailand (but not in Bangkok, even in Patpong, where you hardly breath from pollution) in winter! I apologise that I fear to take the 512 since I live in the city center, and wouldn't be plugged on traffic light, unable to restart after stall! So I will go thru your measures going as quickly as possible to town periphery. But, listen, when cold everything perfect idling at 1100RPM, starting at first key turn and accelerates without any "hole" when stopped in garage. On Friday, it happened again when slowing down in approach of a traffic light, when I had driven for 4km in town. At that time, the start enrichment was closed I suppose of course. Idling when hot go up to 1300RPM, and on a longer drive water temp is at circa 70/75 degrees, oil at 80C say after 30km (doesn't heat compared to 330 GTC or Jaguars). On Monday I will go back to the garage (15km) and I would like to drive their search. Because I suppose that you agree with me that having one or 2 injection pipes plugged wouldn't bring that detonations/impossibility to re-accelarate or stall!! There is something else, I don't want to change the "supposed "oxidised" injection pipes (cost so much the 12 ones!) without understanding the whole situation. thanks again for your help.
you may have a look at the injectors. the old ones has been steel and the newer ones brass what is much better.
Are you saying that this symptom is 1) consistent and occurs all the time/every time, or 2) it happens sometimes, goes away, and comes back? We've certainly had many reports of replating problem with the metal CIS injector lines, but those have mostly been a blocked line, or restricted line, that gives a consistent problem (so more like #1). Ignition system components can also have thermal problems that come and go, being OK cold, but getting worse when warm, and can also come and go when warm (so more like #2). The stock BBi Dinoplex ignition is not the most reliable thing, and many get replaced with an aftermarket ignition ECU -- are you still using the stock Dinoplex ECU or has it been replaced with something else? Since the two injection systems are completely independent on the CIS V12 models, an injection problem on one bank is usually weak running and maybe some missing/backfiring on the bad bank, but your description of the symptom seems more drastic than that -- still could be an injection problem, but you're still at the diagnostic point IMO where you need to determine is it an ignition system problem or an injection system problem.
The comment about detonation concerns me. Boxers are famous for distributor problems and they get neglected. They are mounted where they are exposed to a lot of exhaust heat and need to be removed disassembled and lubricated regularly. Far more often than valves need adjustment. The lubricant gets cooked and the timing advance works poorly or not at all. To make it worse they were built with plastic advance bushings. These swell with time and will also lock up the advance mechanism. When I get a BB with a running or power complaint it is the 1st thing I do.
Good day Jean-Paul, Rifledriver beat me to it, as I remember him stating this time and time again. Effectively, before one focuses on the fuel system, one should double check the ignition system and/or distributor (rotor, advance mechanisms, etc). Remember that your engine requires a correctly operating ignition system along with fuel in order for it to work properly. Focusing on one without checking or confirming the other can be misleading and can waste a lot of time diagnostic time and effort. Cheers, Sam
Thanks to all five of you, that helps me a lot for the troubleshooting. I think that I have the original K Jetronic devices (as described in the 400i iniezione booklet (yellow cover), but I am nearly ignorant in injection matter, but love to learn. To better determine if my problem is occasional or constant, as questioned by Steve, I will make a longer drive with slow down and go (far from the city center traffic lights!!), because at the moment I had more fear in the traffic than clever analysis. Will keep you posted of ding and action plan. have a good day (or night in Thailand), Jean-Paul
Yep I would check the distributor. Pull off the cap and see if the rotor moves freely. It should and if not there is one issue to get resolved. Another very prominent fchat mechanic told me when I got my Boxer that 99% of all fuel related issues are ignition. It's a joke, but very true. This car was restored a year ago and the fuel lines are clogged, very hard to believe and if so I would be concerned about whatever else they supposedly restored. Sometimes vertigris(greenish oxidation) builds up on the contacts inside the distributor cap and this will cause problems. Good luck. They are a blast to drive and when driven more often the problems dissapear.
I had seen in the distributor cap traces of high voltage from 1 contact to the other. I cleaned all but after a short time had same problem - missfiring, mostly when warm. then I cleaned again and used isolation spray. this helps again for a short time but then same problem again. so I took a new cap - and all ok since more than 10 years still I wonder about when it gets restored why there have been troble alraedy with a clogged injection line?
Thanks for your follow up and care taking of distributor. Yesterday was heavy rain here, so that I couldn't go out to test if my problem is clearly consistent or occasional. Will go today or tomorrow. I keep you updated. Best regards, Jean-Paul
I have performed extensive fault finding on the injection system on my BBi lately due to a problem with erratic acceleration. I revealed several findings that might be relevant to you. Before looking at the injection system I went through the entire ignition system and fixed ALL issues first ensuring a good starting point for further fault finding. I need to stress that checking and rectifying defects in the ignition systems is not for the untrained mechanic - You will need technical skills, data knowledge and diagnostic tools to do this job correct. During fault finding on the injection system, I found and rectified the following issues: 1. Two of the steel pipes to the injectors was partly clogged up with debris from the newly done plating process. I unclogged and drifted all the injector piping using a steel cable wire, cleaning fluid and high-pressure air. I also changed out all injectors precautionary. 2. The small fuel inlet filters on the CIS distributor units was clogged up with debris from the fuel system. New filters were installed. 3. Finally I adjusted the throttle plates on the two banks and adjusted the fuel/air ration on both distributors. Best, Peter
Thanks Peter, Indeed the small fuel inlet pipes to injectors must be cleaned as you did and my garage did for #5. take the point for the flag points. Still rain here to test the car on longer drive... so that I learn the K -jetronic in the 400i manual. As complicated (low, high pressure, hot/cold, vacuum, etc) than my former lessons on quantic mechanics when young. BTW, i tested the coil inside my garage: not a M.Marelli BAE 202 B with 3 connectors plus the central one, but a Beru ZS567 with classic 2 connectors+central one. Primary: 1,8 Ohms, secondary 8500 Ohms, not so far fro design spec. Keep you posted, Thanks
Even before you determine whether it's consistent or intermittent, I'm really liking Brian's suggestion to consider the distributor advance mechanism as the most likely suspect because it matches your reported symptom so well. If the distributor advance mechanism is sticking at a large advance, the engine will have a lot of difficulty running at low RPM, and, if it runs at low RPM at all, it will do so in a very "bucking", violent way (and I'm getting that vibe from your original description of the issue). You report that if you coax the engine to higher RPM using the throttle (where it wants more advance), it runs well -- so that matches, too. Getting the distributor advance mechanism checked/serviced as the first step seems much more logical than spending a lot of $s on a new set of injector pipes -- JMO.
Thanks Steve, It looks indeed logical, based on your demonstration, to check the distributor's contacts at first. I will do it and advise you. Jean-Paul
Your distributor has no points. It is fully electronic. The centrifugal advance portion is what you need to check. You will need to remove it and take the lower section out of it. Once you are there the weights should be held by the springs to the shaft at the center. You should be able just by hand to hold the outer piece and rotate the plate with the slots in it far enough to push the weights to touch the outer diameter of the drum with the weights. Then it should return to the first position by itself. Unless the lubricant looks fresh it would pay to just go ahead and relubricate it all. If it is sticking and still has the hat shaped plastic advance bushings I would replace them with bushings made of steel. The piece with 12 tapered fingers is the part that needs to rotate freely from the lower drum.
Hello, Just to update; My garage check everything with Bosh control set for air mistaking on the admission, cleaned injectors, controlled al fuel pressures on K Jetronic, plus counter-pressure of plates, distributors richness. The only issue was 3 to 4 injectors which were giving drops instead of fine pulverisation. they have been cleaned. When I took the car back home (8 miles) everything was Ok, fine acceleration, no stalling on traffic lights, no detonations, just idle slightly high at 1200rpm. When parking home the engine temp was high , over ç0°C due to heavy traffic and managers to enter my garage. After one hour, I wished to move the car and again, it stalls while water is still just below 90°C, and not starting quick as when I took the car. The engine can't stay idle: it stalls if I don't push accelerator at 1500RPM. I will go back to the garage for further intervention. About the injectors, I saw, but can't find it back, that some experts recommended specific injectors. maybe it could be interesting to change the whole 12 of them. Any other suggestions? Thanks a lot. Jean-Paul
Thanks Romano, I will change them. Do you know where I can get these brass injectors in UE? Are they specific for 512 BBi or just "Bosch compatible"? Thanks, Jean-Paul
Hello, just to update on yesterday's message: After inspection of the fuse panel this morning, stalling was due to a fuel pump not activated; the fuse was not fused, but a bad contact due to temperature since the fuses frame are of plastic which deforms at high temp. I changed both, and the engine starts perfect and no more stalling after a run due to normal fuel alimentation. BTW, other fuses look deformed in this panel, in the same manner, which is abnormal; without having blown for over amperage. I will change them for steatite fuses which shouldn't deform but the question of global excessive temperature remains... Best, jean-paul
