CIS gurus, please advise (tech)...

[jdbubb at verizon.net (Dan Bubb)]

I'm far from a CIS guru anymore but here goes anyway.
>From looking at the CIS schematic if you have fuel pressure at the cold start valve, then you should have pressure on the top of the control plunger. So, that part doesn't make any sense at all.
Other than that it seems that you won't get any flow from the injectors if the lower chamber pressure is higher than it should be. Either the DPR or the pressure regulator could be causing that.
Can't think of much else.
Dan


On 8/23/06, Allyn <amalventano1@tds.net> wrote:
> Fellow listers,
>
> OK, so the Rieger is playing games with me as of late.
>
> Background:
> A few months back, on a particularly hot day, wouldn't start after being shutdown hot for 5 minutes.  Gave an initial sputter but no
> continuous fire, suggesting there was some fuel, but not continuous.  After 10 more minutes of waiting, fired right up.  Problem did
> not reappear until recently (below).
>
> Problem:
> After filling up on gas (also a pretty hot day, a few weeks ago), no start.  Acting identical to last time (brief sputter as
> cranking begins, but no complete start).  I let it sit for a day - no dice.  Have to pull 'er home from the base.  Weeks go by -
> still no dice.  I start troubleshooting:
>
> - spark perfect (as suspected).
> - Cracking a fitting loose reveals cold start injector has full fuel pressure and flow supplied from fuel distributor.
> - Cracking an injector line fitting loose reveals no (0) fuel pressure or flow from the injector line outlet of the fuel
> distributor.
> - I crack the other 3 lines - same result.
> - With all 4 lines cracked, and the air flow sensor plate lifted, I cycle the fuel pump again - no flow.  I note that sensor plate
> does not appear to have 'normal' resistance to lifting (it has significantly less).
> - In this condition, I crack the cold start injector line again - plenty of pressure and flow.
> - I lower plate, secure fuel pump, allow all pressure to bleed away through cold start line.  I then lift the plate.  Doing so
> causes further fuel to come from the cracked fitting (from the top of the control plunger I assume - the volume seemed sufficient).
>>
> So... I'm thinking DPR, but I've honestly never seen one fail in such a manner.  It would have to have failed completely shut (or
> for some reason being given full reverse current from the controller), in order to cause these symptoms.  Is there some other path
> through the fuel distribution block that I should check on?  Any other imput here is welcome, as I intend to tear into it further in
> the morning.
>
> Thanks in advance
> Al
>
>