Excessive TZD Turbo lag?

[Alan Hitchcock]

Red BX TZD turbo saloon - see 'I exist' on chat sight. This car had been run for sometime with an incorrect thermostat and got hot regularly I think until the fans failed. I believe it was sold as it was considered knackered and had missed several services. When I got it I gave it a complete service, Oh Matron! Its all black and sticky, and it run up reasonably well and the engine has freed up well since covering about 1500 miles since the start of August including some heavy towing, OK illeagal towing, Alfetta from Ipswich! I plan to short service with a complete change after 3000 miles. That should see most of the crud off. It shows no obvious signs of head gasket. However it continues to have a very bad flat spot in the power band from about 1800 to 2100 revs when the turbo kicks in. I know these turbo cars have a lag but this one is far worse than my 275k mile car yet has only 116k miles up. (Royal Navy would have been proud of the smokescreen on the few occasions I floored the original high milage old dear). Cleaned the intercooler - as tech item - and connections, slight improvement. I have a replacement gasket to fit as a Pug 405 chum said these can fail to seal well when old and disturbed. I think the engine is pretty good despite its poor treatment so it is where to invest some funds to try and cure this annoying gap in power. It is due for a cambelt and water pump at my tame mechanics - he has a proper lift, the BX is designed to be worked opon sat on a lift I think. Lying on the floor just is not so easy! I wondered about injectors which have had some jollop thrown at them, mild improvement resultant, but it seems more like a pump/turbo/instalation problem. The economy is about 42 MPH whereas the old car was doing an incredable 50 plus pretty much whatever I did as I do not tend to go that fast and I am a pretty economic driver. Some good tyres will add a few MPG I think. This also suggest an ineffciency of induction somewhere.

Big Al

[Alan Hitchcock]

Partially answered my own question as I had a couple of hours spare on the car with a bud who knows about things. We got the engine to a reasonable temperature and had the benifit of being able to see the exhaust. This was reveiling as on sharp acceloration it was throwing black smoke which turned to white on over run. This would suggest either over fueling or blocked jets which is consistant with poor economy and a flatspot before the turbo kicks in. So I think the car will go in for Cambelt and Water Pump and we can have the injectors out before letting my chum set up the pump if it needs it. At the same time I can replace the T piece on the hydraulics, fault find on the ramp, clear the octopus pipe if it in fact needs it and fit a new accumilator sphere and see if the car stops popping its return lines on a cleaned out system. My bud was impressed with the suspension which reacted to my dog getting in the back seat. His thoughts are it is basically a sound car despite having had a run in with oblivion at the hands of an uncaring owner. We will see.....