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TL:DR replaced fuel filter, fuel pump and injectors. Car still not starting and checked the injector power feed and found a voltage drop to 3 volts when each injector fired but found that there are resistors in series to the fuel injectors. IS THIS NORMAL?????
I have a 1995 Honda accord 2.2L. It's crank no start.
Here are the parts that have been replaced: ignition coil, Fuel pump, fuel injectors, fuel filter.
Customer purchased vehicle from an auction, to fix and resell the car. Initial symptoms were he could start the car only by spraying carb-cleaner in the intake to get it running. It stalls immediately when supplementary fuel runs out. customer replaced fuel pump, for belief of the cause of no fuel issue. He replaced ignition coil, for belief of causing this issue as well. After these parts were replaced, he requested secondary help from social media. When i first arrived, i scoped the fuel injectors and the waveform that I saw initially suggested that the fuel injectors were mechanically plugged or stuck closed. I observed that there was no pintle hump in the injectors waveform. So I went to the junkyard to get replacements, due to the customer not wanting to buy new ones. Replaced the injectors expecting them to fix the issue. While replacing them i inspected the fuel rail for contaminants, and found none. The issue wasn't fixed. I disassembled the fuel injectors and fuel rail to inspect the port going into the intake for a blockage. Upon reassembly i noticed that there was hardly any fuel pressure in the rail when I loosened the supply line. I kept this in the back of my mind. At this point I was stumped but i suspected a low fuel pressure issue. Couldn't go any further though due to not having a fuel pressure tester. Fast forward a few days, armed with a clear head and a new fuel pressure tester (courtesy of Snap On) I was back at it. Hooked up the gauge and checked fuel pressure after cycling the key a few times too ensure fuel pressure build up. I got 0 psi at the rail. Now remember the fuel pump had already been replaced, so my next thought was the fuel filter was restricted. After a grueling fight with the fuel filter I restored fuel pressure at the rail. The car was still exhibiting the same symptoms as before. I re-scoped the injectors at the control wires to observe the waveform to give me direction. I didn't see anything abnormal with the waveforms now and saw the pintle hump as i was expecting. I decided to check the power feed to the injectors as the car was cranking and saw a funky waveform. I saw a steady battery feed voltage and a dip in voltage down to 3 volts as each injector fired. I was not expecting to see this and I'm a bit thrown off after seeing this waveform. So now I was suspecting a battery feed issue to the injectors but I checked the wiring diagram for the fuel injectors and noticed there is resistors in series before the fuel injectors.
Now is this waveform normal due to the resistors being there???????
johnathon.balderas wrote: I saw a steady battery feed voltage and a dip in voltage down to 3 volts as each injector fired. I was not expecting to see this and I'm a bit thrown off after seeing this waveform. So now I was suspecting a battery feed issue to the injectors but I checked the wiring diagram for the fuel injectors and noticed there is resistors in series before the fuel injectors.
Now is this waveform normal due to the resistors being there???????
Can you post waveform?
~3v is normal for injector feed voltage if you took voltage measurement between the injector resistor and injector. Do voltage drop between battery terminal and injector feed (yel/blk wire), before the injector resistors, to look for wiring problems.
I owned one of these 2.3 for 7 years --- but I never had to do any work on the engine or transmission
Voltage at the injectors looks okay for that type of injector you could check if the injectors are actually spraying either by pressure drop (with gauge connected key on prime the system then disconnect the 12v power at the pump and crank the engine) or visual by either un-bolting the manifold or pullling the fuel rail.
But I suspect stale or badly contaminated fuel is a real possibility
Also be aware spraying alternative fuel into the intake can be misleading as high compression engines can diesel without a spark on some fuels, so make sure there is a spark.
" We're trying to plug a hole in the universe, what are you doing ?. "
(Walter Bishop Fringe TV show)
Got it figured out guys I advised the customer to drain the tank and start fresh and he found diesel fuel in the tank. What threw us off is the customer initially added a few gallons of gas to the tank prior to my investigation which masked the diesel fuel. he added fresh gas to the car and it fired right up. Thank you guys for all of your help.
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