Turbo problem
- Thread starter Fen
- Start date
berg944
New member
For a few months my car has occasionally been shutting off like an over boost but not when revving in lower gears just when foot to the floor in top at 3k rpm.
This was happening more frequently so I removed the boost enhancer and put the standard air filter box back on. Boost dropped back to standard but the problem still remained.
I filmed the aftermarket gauge so as not to miss any over boost and it does not show an over boost when the problem occurs!
Do any other problems trigger the "safe mode"?
When this happens on the motorway I could cruise and only use gentle acceleration. After a couple of minutes all would return to normal.
If this happen on slower roads the engine would only tick over (like the throttle cable had broken) and I would have to switch off to reset back to normal.
Today the "Safe mode" seemed to come on when I was on boost in third and the car became permanently sick!
Tick over is strange, it runs very rough at 500 rpm for 3 seconds then a burst of 1200 rpm for 1 second then back to 500 rpm for 3 seconds and repeats this.
I can get the revs up by gently opening the throttle but too quick and it goes to cut out.
It will drive but its difficult to stop and keep the revs up. 2-3k seems smooth but at soon as I approach 3k rpm the car starts to jerk and if I attempt to drive through it then it gets worse.
Any Ideas most appreciated.
Mike
This was happening more frequently so I removed the boost enhancer and put the standard air filter box back on. Boost dropped back to standard but the problem still remained.
I filmed the aftermarket gauge so as not to miss any over boost and it does not show an over boost when the problem occurs!
Do any other problems trigger the "safe mode"?
When this happens on the motorway I could cruise and only use gentle acceleration. After a couple of minutes all would return to normal.
If this happen on slower roads the engine would only tick over (like the throttle cable had broken) and I would have to switch off to reset back to normal.
Today the "Safe mode" seemed to come on when I was on boost in third and the car became permanently sick!
Tick over is strange, it runs very rough at 500 rpm for 3 seconds then a burst of 1200 rpm for 1 second then back to 500 rpm for 3 seconds and repeats this.
I can get the revs up by gently opening the throttle but too quick and it goes to cut out.
It will drive but its difficult to stop and keep the revs up. 2-3k seems smooth but at soon as I approach 3k rpm the car starts to jerk and if I attempt to drive through it then it gets worse.
Any Ideas most appreciated.
Mike
I was going to suggest much the same as Andrew. I'm not sure the "overboost" cutout actually cares about boost, it's a cutout when the knock sensor detects detonantion which is normally brought on by increasing the boost too much but in this case evidently not. If it isn't too much boost it must be insufficient fuel.
berg944
New member
Thanks for the suggestions.
I was thinking fuel starvation, had already purchased a fuel filter as I do not know when it was last changed.
Also will change Disributer cap and rotor as they are in poor shape, but I do not think this is the problem.
Just removed AFM, TPS, DME, KLR and Fuel Pressure Regularor from a friends 220 turbo so I had alot to play with.
Q. Will a 220 DME work ok on a 250? I think the KLR has the same part number but will check first.
Mike[:'(]
I was thinking fuel starvation, had already purchased a fuel filter as I do not know when it was last changed.
Also will change Disributer cap and rotor as they are in poor shape, but I do not think this is the problem.
Just removed AFM, TPS, DME, KLR and Fuel Pressure Regularor from a friends 220 turbo so I had alot to play with.
Q. Will a 220 DME work ok on a 250? I think the KLR has the same part number but will check first.
Mike[:'(]
berg944
New member
Not solved it yet!
I need to get the tick over problem sorted first. On cold start the tick over is fine at 1000 rpm then about 10 seconds later it starts to fluctuate between 500-1200.
I have changed the TPS and Fuel pressure regulator but these made no difference.
When I changed the AFM the engine would not idle at all so I have put mine back on.
Where is the idle control valve?
Mike[:'(]
I need to get the tick over problem sorted first. On cold start the tick over is fine at 1000 rpm then about 10 seconds later it starts to fluctuate between 500-1200.
I have changed the TPS and Fuel pressure regulator but these made no difference.
When I changed the AFM the engine would not idle at all so I have put mine back on.
Where is the idle control valve?
Mike[:'(]
Guest
New member
the ICV is under the inlet manifold. you can get it off without removing the manifold, but it's tricky. loosen the hoses, undo the bolt holding the bracket on, and try to take it out the front. You'll need to disconnect the harness at some point too.
That could be the source of all your problems. It can give you a major vacuum leak.....
That could be the source of all your problems. It can give you a major vacuum leak.....
The later cars (I think 1990 on) had a catalytic convertor and a lambda sensor, though some had it deleted from the factory, the connector is at the rear of the head.
Check the earth connections are clean, from the battery to the chassis and at the rear of the engine.
Tony
Check the earth connections are clean, from the battery to the chassis and at the rear of the engine.
Tony
berg944
New member
Could not get at the idle stabiliser valve. I did manage to improve the tick over slightly by adjusting the idle air screw on top of the throttle body. Does anybody know how many turns out it should be?
I do get a steady tick over of 500 rpm if I set the TPS fully anticlockwise, anybody like to suggest why?
I went for a short run and the car starts to jerk from 3000 rpm and goes to cut out if I try and force it to 4000 rpm it does not go into safe mode!
I changed the DME and KLR but no difference. I think I will concentrate on this problem and go back to the idle later.
This weekend I have changed the-
AFM
TPS
DME
KLR
Fuel Pressure Regulator
Plugs
Distributer Cap and rotor
Tomorrow I go for the fuel pump and filter, I have soaked the joints in penetrating oil but I think they may snap[&o]
Quickly running out of ideas
]
Mike[:'(]
I do get a steady tick over of 500 rpm if I set the TPS fully anticlockwise, anybody like to suggest why?
I went for a short run and the car starts to jerk from 3000 rpm and goes to cut out if I try and force it to 4000 rpm it does not go into safe mode!
I changed the DME and KLR but no difference. I think I will concentrate on this problem and go back to the idle later.
This weekend I have changed the-
AFM
TPS
DME
KLR
Fuel Pressure Regulator
Plugs
Distributer Cap and rotor
Tomorrow I go for the fuel pump and filter, I have soaked the joints in penetrating oil but I think they may snap[&o]
Quickly running out of ideas![
]Mike[:'(]
Guest
New member
Sounds like you've been having fun with this! []
TPS adjustment is relatively simple, you should hear it click when you've just moved the throttle cam. and I mean "just". To adjust it full a-c just means it's on all the time, and you'll bypass the idle systems in the DME, and will switch off the ISV, which will fully close the ISV and give you a low idle until it warms up. Also, because you have afected the system, you'll get a change in the air content in the system, and it will change the idle speed.
Adjusting the idle is quite simple too. tighten the screw fully, and screw out until the revs read 900rpm. you're supposed to cut out some electrical circuit while doing it, but i've never found it makes a difference. I'm sure the circuit is outlined of clarks though.
It really does sound as though you need to get the ISV sorted. If there is a vaccum problem, then the vaccum fed to the KLR will be wrong, and may kick in the overboost protection. How come you didn't get at it? I forgot you're a "standard" setup right? you'll probably need to remove the airbox and maybe the IC pipe to the turbo to get enough hand room to bring it out. Damn sight simpler than getting the manifold off though......
]TPS adjustment is relatively simple, you should hear it click when you've just moved the throttle cam. and I mean "just". To adjust it full a-c just means it's on all the time, and you'll bypass the idle systems in the DME, and will switch off the ISV, which will fully close the ISV and give you a low idle until it warms up. Also, because you have afected the system, you'll get a change in the air content in the system, and it will change the idle speed.
Adjusting the idle is quite simple too. tighten the screw fully, and screw out until the revs read 900rpm. you're supposed to cut out some electrical circuit while doing it, but i've never found it makes a difference. I'm sure the circuit is outlined of clarks though.
It really does sound as though you need to get the ISV sorted. If there is a vaccum problem, then the vaccum fed to the KLR will be wrong, and may kick in the overboost protection. How come you didn't get at it? I forgot you're a "standard" setup right? you'll probably need to remove the airbox and maybe the IC pipe to the turbo to get enough hand room to bring it out. Damn sight simpler than getting the manifold off though......
berg944
New member
I would not call it fun, working outside when winter suddenly arrives[]. I am enjoying finding my way around the engine.
If the TPS (when set fully anticlockwise) causes the ISV to be bypassed then this would point to a faulty ISV as the tick over was steady when I did this but would not go higher than 500 rpm (normal engine temperature). Before I went for a run I set the TPS to just click when opening the throttle slightly. I could not hear a click near fully throttle!
The idle speed is now mainly between 5-600 rpm and jumps up to 1000 rpm for one second only.
I could not get at the far mounting screw or clamp (both corroded).
I need to find out why it wont rev. I do not think it is the over boost protections it is not shutting down!
I think I will check the timing as well tomorrow just in case it has jumped a tooth when the over boost protection did come in.
Mike[:'(]
]. I am enjoying finding my way around the engine.If the TPS (when set fully anticlockwise) causes the ISV to be bypassed then this would point to a faulty ISV as the tick over was steady when I did this but would not go higher than 500 rpm (normal engine temperature). Before I went for a run I set the TPS to just click when opening the throttle slightly. I could not hear a click near fully throttle!
The idle speed is now mainly between 5-600 rpm and jumps up to 1000 rpm for one second only.
I could not get at the far mounting screw or clamp (both corroded).
I need to find out why it wont rev. I do not think it is the over boost protections it is not shutting down!
I think I will check the timing as well tomorrow just in case it has jumped a tooth when the over boost protection did come in.
Mike[:'(]
Guest
New member
No need to tell me about working in the cold. I can't wait until the buyer comes and picks up the Triumph and I can get in the garage. Hopefully with a heater too!
i can next to guarantee you your idle issues are the ISV. it has all the classic symptoms. There's only one bolt holding the ISV bracket to the head. you can get at it between two of the runners (either 1&2 or 2&3). don't worry about the clamp or the two isolating rubbers until you get it out. they re a pig to get to in situ.
The TPS should only click once when you just open the throttle. any later and the part throttle works on idle maps, any earlier, and you get a bad idle, and the ISV won't work. It's a fine line!.
i can next to guarantee you your idle issues are the ISV. it has all the classic symptoms. There's only one bolt holding the ISV bracket to the head. you can get at it between two of the runners (either 1&2 or 2&3). don't worry about the clamp or the two isolating rubbers until you get it out. they re a pig to get to in situ.
The TPS should only click once when you just open the throttle. any later and the part throttle works on idle maps, any earlier, and you get a bad idle, and the ISV won't work. It's a fine line!.
I sprayed some carb cleaner into the ISV through the pipe that attaches to the head, it improved things. Before spraying it, disabling it (sing the links on the round socket right rear of engine bay - details in the workshop manual in the idle setting section) made no difference after I could set the idle correctly. IIRC the idle drops when you put the link in the plug.
Tony
Tony
berg944
New member
Still trying to work out why the engine will not rev over 3000 rpm!
Checked timing - OK
Removed fuel pump and filter. Filter was seized up and obviously had not been changed in years! I was able to blow through the old filter[:'(] but there was more back pressure than the new one.
I managed to get it off without braking anything.
Just ordered a new fuel line to fit between the pump and filter, it was rotten and should have failed the last few MOT's.
Next weekend I will fit the new filter and line and carry out a flow test.
Mike[:'(]
Checked timing - OK
Removed fuel pump and filter. Filter was seized up and obviously had not been changed in years! I was able to blow through the old filter[:'(] but there was more back pressure than the new one.
I managed to get it off without braking anything.
Just ordered a new fuel line to fit between the pump and filter, it was rotten and should have failed the last few MOT's.
Next weekend I will fit the new filter and line and carry out a flow test.
Mike[:'(]
berg944
New member
I have managed a better idle, a bit low at 600-800 rpm but it will drive without cutting out. I think I will need to sort out the stabiliser valve after I have sorted the other problem
Went for a drive and now have a better understanding of the problem.
I have started a new thread........Low Boost
thanks for your help
Mike[:'(]
Went for a drive and now have a better understanding of the problem.
I have started a new thread........Low Boost
thanks for your help
Mike[:'(]
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