ArcherXXX300

Had this vehicle a long time and it's been built along time. Have around 5K on the build in 10+yrs. Drained Fuel, checked relay, replaced battery. Vehicle runs on starting fluid and dies out. Fuel pump comes on has 12V and primes. When it primes it reaches about 50PSI on the fuel pressure gauge which is mounted on a BDL rail near the return fuel line. However after priming it bleeds off to 0PSI very quickly. Wondering what next steps should be. I'm pretty sure it needs a fuel pump. Advice appreciated for sure, haven't turned wrenches in years. Put the Hondata S300 software on newer laptop, is there anyway to DL the map out of the ECU? I was a member previous,, can't remember email I used or my old username on Hondatech.

punk0mi

Sounds like a dying pump to me if it goes from 50 to 0 psi. That, or you have a substantial fuel leak (which i think you would notice). If you aren't blowing a fuse, then you aren't overdrawing current.

Other thing I'd check is if the FPR is stuck wide open (although I don't think the PSI would drop to 0 even if it were)

If it is a pump, it is easy to change in the EG Remove the rear seat bottom cushion, remove the cover that is in the dead center underneath it, and that is your fuel pump access.

JRCivic1

If it makes fuel pressure during priming and then drops off to zero, it IS making fuel pressure. This suggests that you will need to start and run the car on starter fluid and watch the fuel pressure gauge to see what the running pressures are. If the fuel pressures are up around the 50psi range... you need to go back to basics: Spark and fuel. You will likely have to pull the plugs to see if they are dry or soaking wet. If they are wet and fouled, clean them off or swap out the set and try and crank it again.

JuicedUpRice

like jrcivic1 said, if pump bursts 50psi on prime, it has pressure. If it doesn't hold for at least 1-2 minutes after shutoff, you have a leak. You may have a leak anywhere from the fuel line going to the fuel filter to the injectors. I'm dealing with the same thing currently..

mk378

The fuel pump should keep running while the key is turned to start or the engine is turning. This is mostly controlled by the main relay.

ArcherXXX300

Thanks for replies. Fuel pump primes, it is not the main relay as the pump runs during cranking as well and I checked voltage to pump 12V. Fuel gauge is mounted to a BDL rail, only reason I know the fuel pressure. Since it did start and run on starting fluid but only very briefly that tells me I have spark, when it started I revved it to around 2-3K and it died out. Plugs are nasty fouled/wet (Aftermarket Mugen valvecover I got when I was 17 or so doesn't use gaskets its a POS), I need to drain the oil and fuel in this car and replace plugs. I ordered an AEM 50-1000 to replace the walbro 255lph pump. If I prime the pump and crimp off the return hose my fuel pressure still bleeds down in seconds from 50psi to 0 which makes me think could be pump could be fuel injectors or an external leak somewhere. Not seeing a leak anywhere. Fuel line from fuel filter to rail is braided SS with AN fittings, can't crimp that off to isolate the feed to the rail and measure pressure unfortunately.

mk378

Does the fuel pressure stay up while cranking? This is a yes or no question.

If it does you would next noid light the injectors to see if they are being driven. If it does not you need to find the electrical problem, most likely the main relay.

Also when the car has been sitting it is good to detach the return line to get a sample of what is going through the fuel rail. Really old (years) gummed up gas can clog the injectors.

ArcherXXX300

Replaced fuel pump, drained fuel, Added roughly 7 Gallons of fresh premium (Gauge reading 1/2 full now), changed fuel filter, spark plugs, changed oil. Check 12V at injectors have 12V. Jump the connector for CEL and the CEL just stays on with the connector jumped no DTC's. Unplugged injectors, put a noid light on injector wiring and no flicker. Engine will run briefly on starting fluid and die out. New fuel pump though primes for 2 seconds gets up to around 50psi and settles around 40psi but it IS holding pressure 100000000X better than the old pump and no visible fuel leaks. Injectors or electrical. Any help with the electrical or diag would be great. Have Hondata S300 but don't know how to use it really, it was done by someone else. My bet is I need to check continuity from the ECU to the injector wiring?

JuicedUpRice

try to resolder the main relay internals or you can try smacking the main relay while cranking, or just get a new one and try it.

ArcherXXX300

Main relay. Anyone see any bad spots on it? I thought it looked pretty good.

ArcherXXX300

Disconnected battery, checked continuity from injectors to ECU harness connector A Terminals 1, 2, 3, 5 with respective injector number and have continuity across all. Have 12V in black and yellow wire to PGMFI Main relay, have 12V KEOO (Key on engine off) and 12V hot at all times also. Fuel pump primes and runs, continuity to injectors, 12V at injectors, new fuel, new pump, new fuel filter, new oil, new plugs, changed oil, starter turns, engine turns over smooth will start and run briefly on starting fluid and die out. Thinking stuck closed fuel injectors or possibly bad injectors ECU? Anyway to monitor the signals during cranking with Hondata S300? We have spark confirmed at cylinder 1 with inline spark tester as well. She isn't getting fuel or the ECU won't run it. I have the original tunes on a flash drive thank god but not sure if sitting this long would let the ECU "Lose its tune" from dead battery and sitting for like 4-5Yrs?

ArcherXXX300

Hooked 2 jumper leads up to 9V battery and hooked to each injector with a mechanics stethoscope after priming the fuel pump and removing the spark plugs I can hear the pintle valve open in the injector and the fuel injector is definitely spraying some fuel because fuel pressure goes down to 0psi after connecting 9V jumper to injector. Still stuck here...engine still doesn't run on fuel. I don't want to mess with distributor and ignition timing since it won't run on fuel. Dizzy was replaced in 2013 and probably only had a few hundred miles put on it before it sat for 5yrs.

ArcherXXX300

Replaced PGMFI Main relay with autozone garbage aftermarket relay. STILL CRANK NO FIRE. NO INJECTOR PULSE WITH NOID LIGHT CRANKING...I'm lost A/F here.

ArcherXXX300

I got injector pulse and got the engine to run. other issues now like lost tune and running super super super lean. The primary causes of the no start condition were sitting, Fuel, battery and the Hondata S300. Long story short the ECU lost the tune/map etc. Apparently the Hondata S300 V1 has a battery of some kind in it to help store data etc and I guess it probably went bad. I need to send ECU back to Hondata, no CEL, no DTC's. Fuel issue still I believe and possibly need a new wideband. PLX M300 reads 14.7 or so on initial start and then it starts heading straight towards lean. Key on engine off the PLX M300 will read stoich and then start heading towards lean and staying in that area. I looked through the wiring and how it is currently wired vs a thread from Hondata. Any help here would be greatly appreciated. Key on fuel pump primes to around 45psi within 5 minutes of sitting key on engine off I am down to about 35psi so losing pressure somewhere. I don't see any leaks or visible fuel spray coming out of anything. Fuel lines will be quite expensive for JBtuned. Sugggestions here? How the PLX M300 is currently wired.

PLX M300 Wideband Ground/black wire is at connector D Terminal 22 G/W wire. (Sensor Ground 2).
PLX M300 Wideband Power/RED wire is connected at connector A Terminal 25 Y/B wire (IGP2 Powersource)
PLX M300 Wide Band Gray Wire is connected at connector A Terminal 6 O/B wire (Primary 02 Sensor Heater Control)
PLX M300 Wide Band WHITE wire is connected at connector D Terminal 14 (Primary O2 White Wire)

Hondata article about PLXM300...keep in mind I built this car over a decade ago....
https://www.hondata.com/techplxwiring.html

Does anyone think I should rewire this or just get a new wideband or what? Not sure where the fuel pressure is going either 100%.