'90 200T starting issues

[E. Roy Wendell IV]

On Dec 21, 2006, at 11:05 AM, Briand Parenteau wrote:

> Thanks for the reply... The thermo time switch is shown in the  
> bentley manual, for the MC engine, but upon looking deeper into it  
> I guess you are right.  What I mistakenly identified was the  
> injector cooling fan thermo switch, which I'm guessing now would  
> have nothing to do with my problem.
>
> I have replaced the both ECU temp sensor and multi function temp  
> sensor you had mentioned, and that is shown at the SJM Autotechnik  
> link, within the last 3 months.  I'll go back and test those circuits.
>
> bp
>

Ok then, once again I'm in agreement with Geraint's assessment that  
you are probably now dealing with either a fuel pressure problem and/ 
or a faulty distributor hall sender. You seem to have already covered  
any potential problems with CSV operation by way of changing the ECU  
temp sender and doing the output test while watching for spray from  
the CSV. The only remaining link in that chain is the ECU itself or  
the wiring. I would suggest removing the CSV once again and having  
someone else crank the cold engine while you check for spray. Follow  
the proper safety precautions of course. Spraying fuel plus ignition  
source equals bad day so put the CSV in a clear container of some  
sort and keep an extinguisher handy.

Any drop in fuel pressure after engine shutdown will cause starting  
problems. The leakage paths, in order of highest to lowest  
probability are the check valve on the top of the fuel pump, the  
injectors, and the pressure regulator. The only way to verify this  
fault is to track down a proper CIS fuel pressure gauge and plumb it  
in per Bentley. Then verify that the pressure doesn't drop below the  
specified pressure in the specified time interval. If the fuel pump  
has been replaced recently then it came with a new check valve so  
that could be eliminated. The injectors can be checked by removing  
them, pressurizing the system, and watching for drips.

Hot starting issues are also frequently caused by a distributor hall  
sender on the way out. They tend to develop a fault that is very  
temperature dependent. Just opening the hood for a few minutes so  
that the distributor cools off will often bring them back long enough  
to start the car. When it fails you should get a code stored saying  
as much. Do the no start routine of cranking the engine and then  
blinking out the codes.

Roy Wendell
erwendell at mac.com
Too many type 44 tq
A pair of MR2s