Boost problems

[Ameer Antar]

>>No, its not hard to check.  YOu simply pressurize the engien and listen 
>>for the air.  If it maintains pressure with no leaks yoru fine.   Its a 
>>sure fire way to find vacuum leaks.

but have you checked the pre-turbo hoses for leaks? That can be a problem, 
especially the front turbo hose and the duct on top of the air-flow sensor.

>>Mine have the insert.  Only the REALY early 5kt's didn't have the 
>>insert.  ANd replacing is NOT easy.  They cost $50 each.  Thats a lot of 
>>dough.  I plan to and that likely is my starting problem, but not my only 
>>problem.  thats not the confusing one.  starting problems are easy to 
>>figure out.
that sucks, mine is an '84, the first year type44. You might find injectors 
cheaper here...  http://www.pap-parts.com/   they carry lots of bosch stuff.


>>That doesnt make sense,  55psi is richer.  Less CP leans engien 
>>right.   Anyhow,  my control pressure is fine.  I've checked it.  But its 
>>at the lean end of the spectrum when warm.  So I'm thinking that my P&P's 
>>head and higher compression make it inadequate.  I've tried 5 others but 
>>none are right.      Thanks for the resistance measurement though.  I'll 
>>check that tomorrow.  I think the heater is heating to much.
Actually on my '84 5kT, it's sposed to be 25-30psi cold, then increase to 
about 50-55psi when warm. MC engines are similar, don't know other's specs. 
55psi is not rich, it's actually on the lean side, cuz the higher the 
control pressure, the leaner the mixture. [regulator must lean the mixture 
as it warms up]. The increased pressure is sent to the chamber on top of 
the fuel dist. plunger, making it more difficult for the air-flow sensor 
plate to rise, making the mixture leaner.


>>    All brand new.   And the Warm up reg function fine.  It just changes 
>> to much.   By a tad.
>>Thanks for the help.  I'm check resistance tomorrow if I have time.
I'm assuming yer using an MC engine, you're control pressure should start 
at 21-30psi, w/ the reg. harness disconnected, depending on temp. The 
control pressure should rise to 50-55psi. All this is in the Bentley. What 
do you mean it changes too much? Does it go beyond 55psi or are you talking 
about the AFR gauge? One thing to note about AFR gauges is that they have a 
special behavior. Don't know how fine the resolution is on yer gauge, but 
mine has 30 leds. When they're steady, it means the OXS system is not 
changing the mixture. When it starts cycling, the freq. valve is slowly 
adjusting the mixture to compensate for a slightly lean mixture. At 50% OXS 
duty cycle [which the engine should be normally set to] the gauge should 
cycle at a medium rate. When it gets to 90+%, it will start cycling very 
fast, almost showing a steady light, but you can see a few leds flickering 
VERY quickly. This means the OXS system is trying to richen by max. amount. 
Try to find out if the OXS system is working properly and make sure it's 
trying to richen the mixture when yer running lean. If not, it could be the 
O2, the freq. valve., fuel damper, or ECU, or WIRING!!! Good luck and let 
us know if you discover anything new. I'm sure this diagnosis will help out 
others solve their CIS issues.

-ameer