Thanks,
Reconnecting the secondary does cause engine to reflood. I checked the
injector out of car with a nine volt battery and it clicks OK. When in car,
it does
not leak when fuel line comes up to pressure, only when engine cranking or
running,
which makes me wonder if ECU is telling it to open. With other older FI
systems I've
worked on, the MAP sensor had the ability to stop the engine from starting
or running
by making the mixture go too rich. Would like to be able to verify MAP is OK
or not
to isolate problem to the injector. Voltages to the MAP connector OK, but
there is no
test given to test the MAP by itself. Don't get a trouble code for the MAP,
but don't know
if the ECU would set one or not. No reason to suspect the ECU is bad at
this time, and they
are usually the least likely to fail. Was wondering if there seemed to be a
history of either a
FI sensors going bad or injectors failing before I resort to replacing
parts. Will check the
tandam valve, mostly I'm holding that open manually to see down the barrel.
"jim beam" <nospam@example.net> wrote in message
news:iO2dnZYBP5GMqUbfRVn-qQ@speakeasy.net...
> Mike McDonald wrote:
>> Anyone know how to troubleshoot a 90 1.5L with dual point fuel injection?
>> Will only start and run with secondary fuel injector disconnected.
>> Otherwise floods out and won't run. No trouble codes unless injector is
>> unplugged. Neither injector seems to leak only spray while engine is
>> cranking. Tried all the tips in the Haynes book and all voltages and
>> resistances seem OK for the injectors, MAP, temp sensor, air controller,
>> etc. Any other ideas? Thanks
>
> secondary may be sticking open much longer than required. can you start
> the engine with secondary disconnected, then reconnect once running? if
> so, does it run ok or flood again? the secondary should not [or hardly]
> be injecting at idle, only on enrichment. if you can see it throwing
> fuel, with the engine warm at any rate, it's sticking open.
>
> on a related matter, is the tandem valve opening ok? check it by
> disconnecting the tube on the diaphragm, opening the tandem valve [that's
> the "choke"-like thing at the top of the throttle body] and putting a
> wetted finger over the diaphragm inlet. the tandem valve should stay
> open. if it closes, the diaphragm's shot. that's uncommon. much more
> likely is that the vacuum tube from the actuator is leaking. simple &
> cheap to replace about 1.5".
>