CIS Problem?

[Cody Forbes]

L DC wrote:
> Cody, first off I truly appreciate your response.
>
> I have a few Qs or clarifications if you would.
>
> Cody Wrote:
>
> < When you go to do this you should insert a fuse into
> < the top of your fuel pump relay.
>
> Preferably a 15-amp fuse or it doesn't really matter?

Doen't make a differance, but use a 15 if you have it handy.

>
> < This will turn the pump on any time the key is in
> < the run position.
>
> Meaning turn key to the "accessories on" position and
> leave it on the on position and then do the test,
> right?

Right. Since the 5k ignition only has 3 positions (off, on, and start) you 
don't call the on an "accessory" position since it it required for the 
engine to run and I'd hardly call the engine an accessory heh ;-). It's 
generally called the "run" position, since this is where the key needs to be 
for the engine to run.

>
> Regarding metering plate:
>
> < You should feel some resistance, not alot, but it
> < should take some effort to move it and you will hear
>
> < the injectors spray-
>
> So if I feel resistance in the metering plate then
> that's good?

Right.

>
> Injectors spraying:
>
> < - it sounds like a jet engine starting up as you
> < lift the plate, and they are reasonably loud,
> < there's no mistaking it.
>
> The sound I heard while cranking the engine this past
> weekend was one similar to the one made by a
> taser/stun gun and it came from around the back of the
> air intake manifold. Somewhere below ISV area. And of
> course the starter.

Well the injector noise comes from the injectors only, between the IM and 
the valve cover, and hopefully will come from all 5 of them.

>
> < If there is no resistance in the plate then you have
>
> < either the fuel distributor piston stuck all the way
> < up (unlikely, you would hear the injectors going
> < full bore at all times and the engine would
> < hydrolock),
>
> So this means that whether or not I get resistance,
> while I push the metering plate up with ignition key
> on the on position and fuse on top of the relay, I
> should be able to hear the injectors spraying?

Theoretically yes, but it's also possible that they won't spray at all.

>
> < or there is no "control pressure" meaning no fuel
> < pressure being delivered to the top half of the fuel
>
> < distributor.
>
> What causes lack of fuel pressure being delivered to
> the top of the fuel distributor?

The frequency valve can cause that IIRC, but the frequency valve can be 
tested with the onboard system. I don't have my Bentley manual handy 
otherwise I'd expain the procedure. The warm up regulator (some call it a 
differential pressure regulator) can cause that too. There are other 
options, but I'll check my Bentley before sending you in the wrong 
direction.

>
> As I mentioned earlier, I replaced the fuel pump with
> a brand new Pierburg. I also replaced the fuel filter
> with a new one, Bosch.
>
> Also, when I do the test suggested, I should not
> attempt to crank the engine correct?

Correct, though if the injectors do end up spraying you could try to start 
it. I had a friend with a 5kt that would require being "primed" before it 
would start when hot by manually moving the plate just as I described (a bad 
warm up regulator causes that).

>
> Performing the test would make the injectors spray
> fuel on to the combustion chamber and, thus, should
> only try it a couple of times or so not to accumulate
> excessive fuel in the area?

Thats exactly correct. Don't hold them on for anything more then a second 
which is plenty to hear if they work or not.

>
> By the way, prior to 1st trying to start the car, I
> removed the plastic air box completely, cleaned it
> nicely and replaced it back with a NEW air filter.
>
> Now, I wonder if I intercepted or interrupted
> something that perhaps prevents the air metering plate
> from operating. I doubt it though as I'm usually anal
> careful.

I know how careful and tedious you are usually, I remember watching you 
clean your transmission with a tooth brush for 4 hours when I took it out to 
replace the clutch!!! I seriously doubt you disturbed anything there man, 
theres nothing all that ...um....disturb-able lol.

Hope you get it running soon, that car is way to nice to let sit!

-Cody Forbes
http://www.5000tq.com
'86 5ktq
'86 5k-t-q -Parts
'86 5k-t-q
'87 5ktq - Fast.