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Turbo problem

berg944

berg944

New member
Last week when pulling out of a garage my engine seemed to die. It did not stall but went to a rough idle, every time I went to increase the revs (now in front of a bus, in a bus stop after cutting up two lanes, including the nice man who had just let me out[:eek:]) it went to stall.
Let it idle for two minutes then its OK again.
This happened once last year.
This week after a long blast down the motorway (temperature a bit hotter than usual) I put my foot down in 3rd and just as the boost came in it just spluttered.
I took my foot off and it runs OK until it tries to boost.
Tried to boost in 2nd and held it but had to back off as it was like a kangaroo (or women learning to use a clutch[;)])
Pulled over and left it on idle while I checked all the pipe work, set off again and all OK.

Feels like it might be fuel starvation?

Will the two problems be related?

Any ideas?

Mike
 
I agree with Andrew; fuel starvation. Once my car did the same after having a major service. It turned out that they had kinked the fuel pipe when they installed a new fuel filter.
 
Thanks,

Don't think it will be vac/pressure leak or fuel blockage as it is intermittent.

I think I will strip, clean and test the TPS and AFM in the next few weeks

I think the DME relay sounds favourate so I have pinched the one out of the wifes lux for Walton Hall.

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.
 
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[:'(]
 
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[:'(]
 
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.....
 
Cheers Pikey,

Just had a look under the inlet manifold......It looks scary down there!

Just found this in clark's

If the car experiences a rough idle or idle fluctuates several hundred RPM, this can indicate a sticking idle stabilizer valve. Many people have removed and cleaned them but, this is normally a temporary fix and the valve should be replaced. A faulty O2 sensor can also cause RPM to fluctuate at idle. Unplug the O2 sensor and see if the idle still fluctuates.
Click to expand...
Unplugging the O2 sensor sounds the easiest to try first.

Where is it?
What does it look like?

Thanks

Mike[:'(]
 
there are two black connectors on the back of the manifold. I *think" it's the top one. You may not have one however. I'm not convinced they were fitted on pre-1989 UK cars (but as I have a german car, who am I to comment!?)
 
I think Pikey is correct, IIRC there is a blanking plug.

I will go fishing for the idle stabilizer valve tomorrow.

Mike[:'(]
 
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
 
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![:eek:]

Mike[:'(]

 
Sounds like you've been having fun with this! [:mad:]

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......
 
I would not call it fun, working outside when winter suddenly arrives[:D]. 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[:'(]
 
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 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
 
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[:'(]
 
When my coil broke down it was a nightmare at low revs and OK at high revs. There are 2 resistance readings detailed in the manual, one was in spec one was out. I wonder if the other side of your coil could have failed giving you high rev issues.
tony
 
I will swap the coil at the weekend after I have refitted a fuel pump.

According to the forecast I might have to did a hole in the snow to get underneath[:mad:]

Mike[:'(]
 
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[:'(]
 
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