| Author | Message | ||
     phil randall New User Username: phil_randall Post Number: 8 Registered: 8-2006 |
im considering cleaning the injectors on my 1990 turbo r as they are now 20 years old. although the mileage is still low at 24,000 i would guess that they have a buildup of varnish and crud in them after this amount of time? has anyone any experience of cleaning them and what method would they use? also doe's anyone have a bosch part number for the injectors? many thanks phil (Message edited by phil randall on 30 September 2010) | ||
| James Feller Prolific User Username: james_feller Post Number: 155 Registered: 5-2008 |
hmmm interesting Phil, why do you believe this needs to be done? The injectors certainly can be removed and cleaned via 'ultra sonic' bath if seriously 'gummed up' but is that really the issue? Is the idle rocking ie is it steady on idle? what is the fuel consumption like? does it blow black soot smoke? I would think this is the last resort to have your injectors removed. If your car has done 24,000mls, I would guess the car simply needs driving a more often and using 98 octane fuel. Newer fuels have cleaning agents added to them to help break deposits down in the EFI system. My own 89 Turbo RL sat for a long time prior to my buying it a few years ago, it too had very low Klms on it, 80K I think... and was rocky or had a slightly unsteady idle. It used to hunt on idle going from 500-600rpm. It was not bad but you could notice this rpm and tremor through the car when stationary. I was told to drive it fast and often and it should help. I always use 98oct fuel and now its very smooth, as I try to drive it at least once or twice a week and good long thundering motorway cruises. It does still occasionally hunt on idle but its so slight I dont even worry about it. These cars are known for an uneven or slightly surging idle. So long as its not puffing black smoke I would not worry about it. the K Motronic Digital FI on my car and yours, to my knwolegse, is not manually 'adjustable' or tunable... thats what the digital motronic unit does Phil, it constantly adjusts the fuel,air, mix to set CPU imputs. My recommendation is make sure the car is serviced properly and use high octane fuel and drive it on a few long trips and blow the cobwebs out of it. See what happens after a few weeks of good long drives getting the car up to temps and engaging that fabulous turbocharged V8 lump under the bonnet... there is nothing quite like the thrill of a 'fully engaged' Turbo R storming down the motorway.... Cheers J | ||
| phil randall New User Username: phil_randall Post Number: 9 Registered: 8-2006 |
hello james, thanks for your reply. my reason for suspecting troublesome injectors is a poor cold start that has appeared at this time of the year for the past couple of years. (british weather!) The idle is smoothish with no black smoke. in 2008 i took the car to a RR/B specialist, they added an extra earth strap and somehow raised the idle speed by about 40 rpm (they said it would help with cold start)but it made no difference. so i replaced the EHA valve,fuel pressure regulator, idle speed actuator, cold start injector, fuel pump check valve and fuel pressure accumulator all to no avail. all the spark plugs, leads and distributor caps were replaced 18 months ago.However since my original post i have taken the car to a bosch specialist, he has proven to be very good, he pressure checked the system overnight and found a drop in pressure. so he removed all the injectors to check the burst pressure and spray pattern.Two leaked at low pressure and would only dribble at high pressure, another two had poor spray patterns. so four new injectors were fitted. What a difference!! The car is transformed! it now starts better, runs smoother and is more economical not to mention the improved acceleration! even a high speed vibration (presumably from poor combustion) has dissapeared.I have recently spoken to a fuel injector specialist who told me that the springs in CIS injectors will corrode and weaken over time causing leaking and problems with spray patterns. So i might change the other four! it's only taken me three winters to sort it! as you say james, i think it's time for a few good fast runs. cheers phil | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 2254 Registered: 4-2003 |
Leave well alone unless, as James writes, there is a lumpy idle. These are simple injectors which give very little trouble unless messed around. Sooty injectors will cause lean running, and that will show up with the CO test.
Not quite, James. The mixture is adjustable, and must be set in range so that the Jetronic / Motronic system can fine tune it. Once the motor is fully warmed up and stabilised idling at 580rpm, the Lambda sensor should be disconnected to operate the system in open-loop. Then the CO should be set to 0.8%-1.0% BEFORE the catalytic converter. The Lambda device, once reconnected, will then keep the CO level constant via the KE3 Jetronic (AKA Motronic) or K/KE2 Jetronic as applicable (note that all Australian-spec cars have closed loop with K, KE2 or KE3). Australian-spec cars have a special blanking plug in the exhaust pipe just after the Lambda sensor provided specifically to insert the CO test meter. German, Swiss and Austrian-spec cars even have a special small pipe extending to the to the carbody sill with a blanking plug for the same purpose. That makes the test and adjustment even easier. Note that far too many garages test the CO in closed loop during the yearly statutory exhaust gas tests, measuring at the exhaust outlet after the catalytic converter, then twiddle the mixture control. Invariably, the mixture setpoint will then be out of range. If the CO is set out of range, as is often the case, then the control system will operate on its limit and mixture control does not function. This is especially true when the cat is not 100%, and by twiddling the setpoint the mixture is forced past its controlled end stop to “compensate” for the cat. Bad news, as this may lead to burned valves and localised overheating. RT. | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 2255 Registered: 4-2003 |
By the way, this is the exhaust gas takeoff, for setting the mixture, as fitted to Austrian, Swiss and German-*spec cars from 1988.  | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 2256 Registered: 4-2003 |
Phil, I had a little trouble with cold start injection in Europe too, and solved it with a small modification applicable to all cars until about 1994. See page 18 of http://rrtechnical.info/sz/sz87/b6a.pdf Originally, the cold start injection system is a little overzealous. The new timer limits the amount of cold start priming, as I found that the car was slightly harder to start in Autumn especially, but also in Winter, requiring cranking for as long as 3 seconds, due to excessive cold-start injection. With the timer installed, I fine tuned it only about twice initially, and starting has been fine ever since in ambients ranging from -20C in Europe to +43C in outback Australia. RT.  | ||
| James Feller Prolific User Username: james_feller Post Number: 156 Registered: 5-2008 |
Hi Guys, RT, I should have known not to say 'not manually adjustable' you would have found out how to do it I'm sure!!! :o) Phil, my advice is purely layman. I am by no means a mechanic or expert here. Its my unbridled enthusiasm and interest in these fabulous 'British lorries' that keeps me talking and boring my friends shitless... Richard of course is extremely knowledgable on these cars and I was blessed to have him drop round to my place a few months ago and we compared Turbo R stories over a few wines... quite a lovely evening it was too. It must be time for another one Mr Treacy!!! Phil, with a little bit more info from you now in your second post as to the troubles you expirenced Richard has steered you in the right direction. Personally, I must have been lucky with my Turbo as I simply had the car serviced from bumper to bumper and drove the christ out of it and to date its been an utter pleasure in regard to starting, hot, cold in both winter and summer ambient temps. On reading your posts re your injectors, it sounds like the car has not had good fuel or has indeed sat for some period of time. I am surpised you have had to change injectors but I suppose as Richard says they do wear out. My recommendation stands re Fuel quality, I would put nothing but the highest quality and oct rating fuel into them. I put 98 in my Spirit as well, it is injected too and the idle on my Rolls is so smooth and quiet half the time you are not even aware its on. The Bentley is nowhere near as slient or smooth on idle as the Rolls. Dont get me wrong though my Turbo is good and does not hunt too much anymore through the rpm range of 500-600rpm but its certiably not as silent and steady as the Rolls. I'm into the habit now of starting the Turbo slowly. What I mean is insert the key, and twist through lock, ign, then start giving about 1/2 second delay between each phase. The reason for this is I have found the car 'likes' the chance to pressurise the fuel right up prior to cranking rather than having to do this while cranking. Does this make sense? RT I have no idea really if this does anything at all, but I do notice the car fires up better either stone cold or warm. If I'm very quick with the key particularly if cold and having not been driven for a week or so the car can take 3 seconds or so of cranking and then fires up. I believe by allowing the car to have this slight delay it helps quick reliable first time starting... but again I'm not sure if this is just a placebo. I'm probabaly just being a bit babyish with it but that's me. Glad to hear its going like a freighttrain again Phil and get to a motorway NOW and give it a good run. Take note of what RT has stated above as well. I have numerous times walked into my mechanices quoting Richard's advice with regard to service items, I would never have known about myself, to my mechanice surprise. The last one was the twin distributor drive belt... I had no idea the car had this and when I first got the car I requested it be renewed much to my mechanics delight. Glad I did too as the original one was pretty well knackered. Happy Turboing Phil, RT another catch-up is required soon. Cheers J | ||
| phil randall New User Username: phil_randall Post Number: 10 Registered: 8-2006 |
my thanks to richard and james, james, it would appear that i have developed the same starting procedure as you..im not sure that it acheives anything either! and i will try some higher octane fuel as you suggest.i will also give it a good long/fast run just as soon as i recover from thursdays keyhole surgery on both knees. Richard, 95% of my cold starting problem is at about +15c ambient and lower (the thermotime switch has been replaced). do you feel that your timer would help the situation? did you fit the components on a form of printed circuit board? thanks phil |
