Response to: Phil Payne on Fuel additive cleaning of injectors (Was long cranking)

[Louis A. Mulieri]

Sorry to re-post this but I forgot to put in a subject line on my first 
post.

Date: Sat, 6 Dec 2003 08:51:21 -0500 (EST)
From: "Louis A. Mulieri" <mulieri at physiology.med.uvm.edu>
Subject: (no subject)
To: quattro at audifans.com
Message-ID:
        <Pine.LNX.4.44.0312060819150.32367-100000 at physiology.med.uvm.edu>
Content-Type: TEXT/PLAIN; charset=US-ASCII

Hi Phil,
        Thanks for your suggstion to measure residual pressure instead of 
guessing that injectors are leaky. I thought it might be an easy 
shot-in-the-dark way of testing for the outside chance that my long 
cranking after 1 hr cool-down could be caused by empty injector lines 
(retired with more time than money to replace injectors). 

Actually, it seems unlikely that my long cranking is due to empty fuel 
lines 
caused by a leaky fuel pump check valve because my engine starts normally 
after an overnight rest even if that was preceded by a long crank, 
no-start s
ession. It also seems unlikely because jumping the fuel pump relay to run 
the 
pump for a minute before attempting to start does not eliminate the 30 
second-long, no-start cranking after 1 hr or 2 hr (but not 3 hrs).

It also seems unlikely that my no start condition is due to leaky 
injector/CSV flooding since persistent cranking will eventually start the 
enging and there is no black smoke evidencing flooded cylinders (I also 
found dry spark plug after a long-crank no-start session).

My next guess is that my CSV is not delivering at start up because the 
computer is getting a "normal engine temperature" signal when the engine 
has cooled for between 1 to 3 hours and therefore not activating the CSV. 
I have not been able to identify which of my at least 3 temperature 
senders is 
the one that informs the CSV computer controller. I plan now to test the 
CSV role by running a wire from front seat to terminal # 2 of the CSV plug 
and 
giving it a short grounding or two to see if that converts a long crank 
into a start-up. Is this a good plan?  

Thanks for your help,
Lou
'88 5KCSTQ

>Date: Sat, 6 Dec 2003 13:14:06 +0100
>From: "Phil Payne" <quattro at isham-research.com>
>Subject: Re: Injector Cleaning by fuel additives?
>> I've had numerous 
>>suggestions from list members that my 
>> long-crank, hot start problem could be due to leaky injectors. Has 
>>anyone 
>> found a fuel additive that corrects injecor leaks due to sludge-etc 
>> buildup?>Don't guess - measure.

>Attach a fuel pressure gauge and see if the system maintains residual 
>pressure
>at shutdown.

>-- 
>  Phil Payne