Mike McDonald wrote:
> Thanks again. Will check out main relay, but since car will start when the
> plugs and throttle body are dry and secondary injector is disconnected, I
> doubt its bad. Could check signal to injector, but don't know what a proper
> one should look like. Simple DC check shows its not always on and in range.
> ~5 volts I think last time I checked. Voltage to air injector OK and its
> resistance OK also. If I don't come up with anything new, I guess I'll
> start with a new injector and see what happens. Hate to start replacing
> parts without knowing they're bad as it can get real expensive real fast.

i sympathize, but you're caught between the rock & hard place of not
having more extensive test equipment & not wanting to unnecessarily
replace parts. if you don't have the gear, you got to replace parts.
all you need is a used injector. it's not that expensive. poke about
your local junk yard.

>
> "jim beam" <nospam@example.net> wrote in message
> newsOGdnZd-r586N0DfRVn-jQ@speakeasy.net...
>
>>Mike McDonald wrote:
>>
>>>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.
>>
>>that's good, but clicking != guaranteed correct function.
>>
>>
>>> 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.
>>
>>the best check is to get a scope & look at the signal. if it's the same
>>as a functioning dpfi civic, it's not the ecu, but it's not likely to be
>>the ecu anyway.
>>
>>
>>> 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.
>>
>>ecu will almost certainly set a code on the map sensor [or ap sensor in
>>the passenger cabin] being defective.
>>
>>
>>> 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.
>>
>>if you hold the tandem open while you're running the engine, you'e going
>>to have a problem - it works /with/ the auxillary injector to make sure
>>there's sufficient vacuum to vaporize the fuel. no restriction from the
>>tandem = no vacuum = "excess" fuel.
>>
>>btw, what symptoms make you think it's flooding? if it's simply not
>>starting, check the main relay. your vintage civic is a prime candidate
>>for this very common problem.
>>
>>otherwise, get yourself to a junk yard & get an auxillary injector. they
>>rarely fail, so a used one is likely to work just fine - at least good
>>enough to get a decent diagnostic.
>>
>>
>>>"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".
>>>>
>>>
>>>
>>>
>
>