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.
"jim beam" <nospam@example.net> wrote in message
news
OGdnZd-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".
>>>
>>
>>
>>
>