280i, US spec - dies at idle
Discussion
I did have a similar problem once, and it turned out to be a bad electrical connection on the WUR - this means fuel enrichment (=choke) is still happening when it shouldn't. A bit of wd40 and a clean solved it.
As you say, it could also be an air leak somewhere, probably in the large connector pipe, but check smaller airpipes around idle speed valve. (the one next to the WUR)
Has the idle been rough for a while or this is new ??
As you say, it could also be an air leak somewhere, probably in the large connector pipe, but check smaller airpipes around idle speed valve. (the one next to the WUR)
Has the idle been rough for a while or this is new ??
Idle has never been particularly smooth. Below 1000 rpm's its lumpy. But it has never died on me. I've had rpm hunting issues at idle and have tried to adjust the mixture using a dwell meter with limited success. Previous owner was using the butterfly stop screw to adjust the idle and had no idea the idle screw was where it was. Been searching on how to correctly reset the butterfly but no luck. Going to buy an exhaust anaylizer to try and help dial the mixture in once I get the idle sorted.
Bring a US car, closed loop system I think, it has an O2 sensor. I have no idea if this is original but it is possible. Could be a factor.
Bring a US car, closed loop system I think, it has an O2 sensor. I have no idea if this is original but it is possible. Could be a factor.
Edited by GBinUSA on Sunday 27th September 21:24
The reason I asked is that with a continuous type injection system, the injectors have the toughest job at IDLE, which is not what many people think.
If you've had rough idle for a while, it could be one or more injectors are either dirty or worn out. What happens is that they stop atomising properly on light throttle/idle. Good news is injectors don't cost as much as Efi ones, or didn't used to anyway, and they are Bosch ones, so not stuck to Ford dealers. Also may be able to get them cleaned, but they do wear out.
(Also can try Audi / VW dealers - a lot of older VWs, Audis, had this system so they may be able to help you out)
I put new injectors in mine a while ago, afterwards idle was the smoothest it had ever been - no engine shake at all !! Low end throttle response was much smoother and pickup better, so it is noticeable.
Throttle screw stop (on top) is simply to stop plate getting wedged on sides of casting - there was a procedure somewhere, I think it basically says set screw so that you can just get a very thin feeler gauge in (3 thou? something like that), or when off the car, so you can just see a sliver of light when held up.....
Use idle screw underneath !! (you already know that of course)
If you've had rough idle for a while, it could be one or more injectors are either dirty or worn out. What happens is that they stop atomising properly on light throttle/idle. Good news is injectors don't cost as much as Efi ones, or didn't used to anyway, and they are Bosch ones, so not stuck to Ford dealers. Also may be able to get them cleaned, but they do wear out.
(Also can try Audi / VW dealers - a lot of older VWs, Audis, had this system so they may be able to help you out)
I put new injectors in mine a while ago, afterwards idle was the smoothest it had ever been - no engine shake at all !! Low end throttle response was much smoother and pickup better, so it is noticeable.
Throttle screw stop (on top) is simply to stop plate getting wedged on sides of casting - there was a procedure somewhere, I think it basically says set screw so that you can just get a very thin feeler gauge in (3 thou? something like that), or when off the car, so you can just see a sliver of light when held up.....
Use idle screw underneath !! (you already know that of course)
Edited by RCK974X on Sunday 27th September 21:36
Mmmmm...The stop screw could be causing this...I used to be able to run Delilah at 650rpm...Although 800rpm was better....
There was one time that the guys at power engineering touched the adjustment screw in the metering unit and Delilah would not idle..They started messing around with the stop screws but luckily i was there to stop them and adjusted the mixture back to how i was shown..Once smooth idle was found you blip the throttle to see how quick it comes back to idle, If its slow then it was a fraction of a turn on the metering head adjustment..There seems to be a central point and either side of it the car will run shyte..However this was only adjusted to match the 3 stage purpose built WUR that i had built for the Supercharger fitment...
I think the stop screw is a s Andy say's...I just remember the ford guys telling me to never touch that, If i need to adjust it then use the idle screw under the throttle body..
There was one time that the guys at power engineering touched the adjustment screw in the metering unit and Delilah would not idle..They started messing around with the stop screws but luckily i was there to stop them and adjusted the mixture back to how i was shown..Once smooth idle was found you blip the throttle to see how quick it comes back to idle, If its slow then it was a fraction of a turn on the metering head adjustment..There seems to be a central point and either side of it the car will run shyte..However this was only adjusted to match the 3 stage purpose built WUR that i had built for the Supercharger fitment...
I think the stop screw is a s Andy say's...I just remember the ford guys telling me to never touch that, If i need to adjust it then use the idle screw under the throttle body..
Yep good injectors will get down to there, but 850rpm is recommended.
Found 'official' throttle plate adjustment from old Bosch book (by C. Probst - a sort of workshop manual)
The disclaimer is first....some snippets of interest
"Throttle stop screw ...not for idle adjustment...prevent plate closing too far.....factory set...." (etc. etc)
Then it gives a procedure - here is quote of the essential sentences, other safety crap edited out.
Loosen locknut.
Use screwdriver to back off screw until there is clearance between screw and valve lever (or the stop on some models).
Place a piece of thin paper between screw and lever. With throttle closed, turn screw until it just contacts the paper.
From this position, remove paper and turn screw exactly 1/2 turn.
Tighten locknut.
END.
So paper is just to check I guess ... I think this will do pretty much the same as the thin feeler blade ! ...
Found 'official' throttle plate adjustment from old Bosch book (by C. Probst - a sort of workshop manual)
The disclaimer is first....some snippets of interest
"Throttle stop screw ...not for idle adjustment...prevent plate closing too far.....factory set...." (etc. etc)
Then it gives a procedure - here is quote of the essential sentences, other safety crap edited out.
Loosen locknut.
Use screwdriver to back off screw until there is clearance between screw and valve lever (or the stop on some models).
Place a piece of thin paper between screw and lever. With throttle closed, turn screw until it just contacts the paper.
From this position, remove paper and turn screw exactly 1/2 turn.
Tighten locknut.
END.
So paper is just to check I guess ... I think this will do pretty much the same as the thin feeler blade ! ...
Real life -
A long time ago, I bought a really cheap Granada 2.8i Automatic for engine (and injection) spares when I was still in UK, It was cheap because owner couldn't get it to idle, and even his local garage couldn't fix it (according to him anyway). This was a real pain to drive home, because it kept stalling, and you had to time a restart with foot on gas, and catch it just right to shove into 'D' otherwise it would die again. It was fine on decent throttle and accelerated well.
Funny though, worked perfectly when cold......
It was the injectors, I thought it was the mixture adjustment or idle setup, etc. but no.... I took injectors out and three just dribbled when metering plate lifted slightly. Lift plate more, and they each started to spray (not a clean cone pattern, but at least a spray) That's when I knew. Swopping injectors around with some other (dodgy) spare ones, and it would then idle, but a still bit rough. I took car apart for spares and kit projects, so I never did fix it properly, but I remember ...
A long time ago, I bought a really cheap Granada 2.8i Automatic for engine (and injection) spares when I was still in UK, It was cheap because owner couldn't get it to idle, and even his local garage couldn't fix it (according to him anyway). This was a real pain to drive home, because it kept stalling, and you had to time a restart with foot on gas, and catch it just right to shove into 'D' otherwise it would die again. It was fine on decent throttle and accelerated well.
Funny though, worked perfectly when cold......
It was the injectors, I thought it was the mixture adjustment or idle setup, etc. but no.... I took injectors out and three just dribbled when metering plate lifted slightly. Lift plate more, and they each started to spray (not a clean cone pattern, but at least a spray) That's when I knew. Swopping injectors around with some other (dodgy) spare ones, and it would then idle, but a still bit rough. I took car apart for spares and kit projects, so I never did fix it properly, but I remember ...
Edited by RCK974X on Sunday 27th September 23:14
i will reset the butterfly stop screw using that method Andy. Thank you for posting. Out of interest, how many turns out from seated would I normally have to turn the idle adjustment screw to get a good idle.
Is there any other retailer than Burton Power for the injectors?
Is there any other retailer than Burton Power for the injectors?
Edited by GBinUSA on Monday 28th September 06:20
Hmmm, that's hard to answer, never thought of it that way, but I reckon it must be at least 4 turns to start with.
NOTE - the idle speed can also be affected by a faulty auxiliary air valve, so make sure engine is fully warmed up before trimming the
idle, and the aux valve does NOT fully close (by design), so there's always a bit of air flow through the valve.
NOTE - the idle speed can also be affected by a faulty auxiliary air valve, so make sure engine is fully warmed up before trimming the
idle, and the aux valve does NOT fully close (by design), so there's always a bit of air flow through the valve.
GBinUSA said:
Out of interest, how many turns out from seated would I normally have to turn the idle adjustment screw to get a good idle.
Is there any other retailer than Burton Power for the injectors?
Hi mate...I recall 2.5-3.5 turns from fully closed....Is there any other retailer than Burton Power for the injectors?
I always used kmi petrol injection for any of the 280i parts..This company is very experienced with K-Jetronic, Steve is the guy you want to contact...You can tell him that i recommended you....He actually helped me diagnose the hot start issue that i had that no-one else seemed to know about...Well worth a call...Or email...
https://www.google.co.uk/url?sa=t&rct=j&q=...
GBinUSA said:
Is there any other retailer than Burton Power for the injectors?
They are actually Bosch items, there is a part number stamped on them. Also VW and Audi used this injection system quite a lot in the 80's before Efi took over, so they may be able to help.
I went to a Bosch dealer here in NZ, and armed with part number, only took 2 weeks to get new ones.
My car has only done 23k miles since 1986. With all that sitting I'm sure corrosion has taken it's toll on the inside of the injectors. I've tried injector cleaner but to no real success. I'm sure it would benefit tremendously from a six pack.
I'm away from the car for about a month, so can't pull an injector for a part#. Anyone know if they all used the same type, Capri 2.8i?. KMI has the Capri ones in stock.
Bonnet open or closed I get the same result, but checking for compressing of the intake hose is an excellent suggestion.
I'm away from the car for about a month, so can't pull an injector for a part#. Anyone know if they all used the same type, Capri 2.8i?. KMI has the Capri ones in stock.
Bonnet open or closed I get the same result, but checking for compressing of the intake hose is an excellent suggestion.
Had sometime this morning to play with the my car. I reset the butterfly and idle screws, which didn't improve anything. Then I thought I'd give a 1/4 turn on the mixture screw and see what happens. The engine started to smooth out. One more 1/4 turn and things got even better. I left alone after a 1/2 turn. Idle is good now. Blip the throttle and it settles quickly back done to 800 rpm with no hunting. Test drive to come but pretty happy so far.
GBinUSA said:
Had sometime this morning to play with the my car. I reset the butterfly and idle screws, which didn't improve anything. Then I thought I'd give a 1/4 turn on the mixture screw and see what happens. The engine started to smooth out. One more 1/4 turn and things got even better. I left alone after a 1/2 turn. Idle is good now. Blip the throttle and it settles quickly back done to 800 rpm with no hunting. Test drive to come but pretty happy so far.
Thats really good news...Even a quarter of a turn is a lot on the mixture but you will know when it is right...By the sound of it you have it near to spot on, If you can get a CO tester on it all the better but thats really good progress as it stands..Just make sure you put aside a bit more time for the test drive...Just incase you are overcome by the TVR silly grin...Cheers...ZigaNot an official procedure, but you can GENTLY push and pull on the adjuster hex key to double check. Pushing down makes mixture weak, so engine should run slower or stall, and pulling makes mixture rich, and should also make engine speed drop off a bit. (when pulling up twist or push hex key sideways to there's enough friction to lift the mechanism....)
Best setting (for UK) is fastest idle then weakened just a little so idle slows very slightly (this is the 'slightly weak' idle setting which gives best CO emissions). At least that's what I've always done, and had no problems with CO.
Just like the old SU carbs in many ways....
Best setting (for UK) is fastest idle then weakened just a little so idle slows very slightly (this is the 'slightly weak' idle setting which gives best CO emissions). At least that's what I've always done, and had no problems with CO.
Just like the old SU carbs in many ways....
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