Tuesday, September 20, 2011

Is my fuel injectors bad?

when i start up it runs very low, and if i don't press the pedal to give it some gas it'll shut off within ten seconds. But after it has time, about five min, it runs better and better until its running great. I have bad fuel miliage for a honda civic 1990 i think. I changed the fuel filter last month, air filter, spark plugs, put fuel injecter cleaner and i'm wondering what else is there?
Is my fuel injectors bad?
what i would do is check fuel pressure and for any engine codes.. if pressure is low check these things...

fuel pump, fuel regulator, injectors and filter but u said u did that. also check pulse on the injector connectors see if the pulse is good. your vehicle may be running too lean... anything loose? spark plugs or anything? hear a tick of any kind? if its just occuring after tune up may have not installed correctly of anything... also disconnect the mass air flow if it has one and see if it runs fine after that. if it does replace it or clean it real good with carb cleaner. also idler check it and clean it. if its got a map sensor disconnect and clean that
Is my fuel injectors bad?
Have the fuel injectors professionally cleaned.
for hondas, there are two things that affect the cold engine at startup. Idle air control valve (IACV) and the throttle body, there is a small hose that carries coolant to the throttle body that controls the %26quot;choke%26quot; automatically. I really think the IACV is dirty, but if you clean it and it still gives you problems, make sure those lines are there, and open the air bleed, if you have air trapped in your cooling system it can cause problems as well.
The injectors may be dirty, but I've never encountered a running engine with injectors so dirty that a bottle of fuel injector cleaner in the tank.



The low idle when cold is very often a dirty throttle body and/or dirty idle air control (IAC) valve. The quick and dirty (he he) way of cleaning those is to warm up the engine with the filter assembly unfastened from the throttle body and then spray carburetor cleaner liberally in the intake as you work the throttle to keep it running. If that doesn't straighten it out you probably need to do it the right way - disassemble and swab on, wipe out carb cleaner.
You might need to replace the injectors. Another choice would be to get the injectors cleaned by a professional with the right equipment.