- Joined
- 27 June 2003
- Messages
- 4,618
Tried to remove the plug but that philips screw that holds the connector is stripped..
I've had my injectors cleaned and balanced by RC but this was 5 years ago or so...
temporary loss of power during acceleration :(
- Thread starter darock
- Start date
Tried to remove the plug but that philips screw that holds the connector is stripped..
I've had my injectors cleaned and balanced by RC but this was 5 years ago or so...
- Joined
- 15 May 2004
- Messages
- 6,898
Which plug?
Injectors: as long as you drive the car periodically like once a month the injectors won't get clogged. But if you had a longer period (>3 months) within the last 5 years where the engine didn't run at all the chances are high that the don't flow properly. My friends car had this recently after a 6 months pause.
Injectors: as long as you drive the car periodically like once a month the injectors won't get clogged. But if you had a longer period (>3 months) within the last 5 years where the engine didn't run at all the chances are high that the don't flow properly. My friends car had this recently after a 6 months pause.
- Joined
- 27 June 2003
- Messages
- 4,618
the connector that is plugged into the resistor (heat sync looking thing on the passenger side bulk head) there is a Philips screw that holds it into place right?
I'm having an intermittent stalling problem per the "nsx 2000 Stranded" thread. What type of fuel pressure gauge did you buy and where. How do your read the gauge under load unless your gauge is 8 feet long???
thanks
Mark Deffendall
thanks
Mark Deffendall
- Joined
- 1 December 2023
- Messages
- 48
Adding on to this post .I’ve been having issues with 1992 that is same problem.codes 1 and 2 come.car hesitates at lower rpm but pick up at vtec ranges.when i full throttle it to try to pick up speed that’s when the check engine light occurs.car has about 250k miles.I’ve changed fuel pump oem,o2 sensors,spark plugs,injectors(non oem),fuel filter,and cleaned throttl body.can bad fuel pump resistor or main relay be and issue?Or can it be I just need my original injectors cleaned and these non oem ones not helping(Honda 6 NEW OEM FUEL INJECTORS 06164-P0A-000)?can it be due to exhaust system as well maybe clogged cat or exhaust leak?sorry for all these questions been chasing it for a while
So that was kind of hard to understand.
First off, if the engine runs the main EFI relay is not the problem.
Codes 1 and 2 on pre OBD II cars are kind of cryptic. They just mean a problem with the O2 sensors which can be a wiring problem of a fuel mixture problem. If there is a fuel mixture problem you would also expect to get a code 43 and code 44. However, the pre OBD II diagnostics are not the perfect. It would be unusual to have a wiring problem with both sensors at the same time so it seems reasonable that you have a fuel mixture issue.
It is not clear what you have done with the injectors. Are the non OEM replacements supposed to be exact replacements for the original injectors with the same flow rates and offsets? Did the problem occur after you changed the injectors. If that is the case then the non OEM are suspect. If the problems appeared long after or existed before the injectors were replaced then the problem is unlikely related to the injectors.
Have you done the fuel pressure and fuel pressure regulator check as described in the service manual to confirm that they are in spec?
Since the engine has 250k miles on it, have you done a compression check and checked your valve clearances to confirm that the engine is in good condition. If the engine has been flogged or the valve clearances are way out these can mess with you fuel mixture.
- Joined
- 1 December 2023
- Messages
- 48
Thanks for info.it’s only codes 1 and 2 that pops up when checking.CEL goes away when shutting off car.Does it save the code in ecu even if car was shut off?I also noticed very strong gas smell in engine bay around intake area when starting up car.is this normal?don’t see any damaged hoses anywhere and when dropped the tank to change fuel pump there was no leaks.
Don’t think it’s is injectors as with my originals it would get the same issue.new injectors are same spec as OEM and are Honda brand
I have not
,I will be doing fuel pressure testing this week.engine is supposedly a 80k motor with 250k chasis(according to previous owner).will get compression checked as well to be sure if that’s the case.Do you know what the fuel pump resistor should be at to be in spec?I have heard this could be a issue as well
The ECU stores error codes in the ECU memory. I can't remember exactly how many it will store; but, it displays them in the order of newest to oldest. However, that assumes that the ECU 'keep alive' power is supply is working. If you are out driving and the CEL come on you should be able to turn off the car and then turn the car back on and the CEL will normally stay lit up indicating a stored error code. Even if it doesn't stay lit up the code should be stored in the ECU. After you turn off the car you should be able to trigger the display of the stored codes by jumping the SC connector and turning the ignition to run. The stored codes should stay in the ECU until you reset them by pulling the clock fuse or your battery goes dead.
The smell of gas in the engine compartment is not normal; but, without more details can't comment on what might be wrong. When you do the fuel pressure test, once you shut the pump off the pressure should stay constant or drop very slowly. If it drops fast then you have a leak some place, a faulty check valve in the pump or a fuel pressure regulator problem.
If the problem existed prior to installing the new injectors then it is unlikely to be the new injectors.
Honda does not publish a spec for the fuel pump resistor; but measurements by Prime members indicate about 0.73 ohms for early cars and 0.55 ohms for later cars. I don't know what the change date is. Check the wiring on the fuel pump resistor as the resistor gets hot and the wiring can deteriorate resulting in a poor connection to the fuel pump. Some details here:
The smell of gas in the engine compartment is not normal; but, without more details can't comment on what might be wrong. When you do the fuel pressure test, once you shut the pump off the pressure should stay constant or drop very slowly. If it drops fast then you have a leak some place, a faulty check valve in the pump or a fuel pressure regulator problem.
If the problem existed prior to installing the new injectors then it is unlikely to be the new injectors.
Honda does not publish a spec for the fuel pump resistor; but measurements by Prime members indicate about 0.73 ohms for early cars and 0.55 ohms for later cars. I don't know what the change date is. Check the wiring on the fuel pump resistor as the resistor gets hot and the wiring can deteriorate resulting in a poor connection to the fuel pump. Some details here:
Adding to @Old Guy 's good advice above, the behavior you're describing (setting aside the CEL codes) is nearly always due to the fuel pump failing. But, you've replaced the pump. The next most common issue is the ECU going into its default open loop maps due to an O2 sensor failure. The car will run rough and have weird hesitations in the map range where it should be in closed loop, and it will feel good in VTEC since those are open loop fuel maps by design. I would replace both O2 sensors, pull the clock fuse and see if you get the CELs again.
The third most common issue is the fuel pump resistor, which controls whether the pump runs in "low" or "high" mode. A failed resistor will force a permanent "high" condition, which will result in incorrect fueling in the "low" range of the fuel map. If closed loop is running properly, the ECU can compensate for some of this but only up to +/- 30%. Again, you'll get weird behavior at low speed but VTEC will feel fine.
Finally, we're starting to see the fuel pressure regulators go bad on the early cars. This will cause the same symptoms, but not throw a code.
A few things to note:
The third most common issue is the fuel pump resistor, which controls whether the pump runs in "low" or "high" mode. A failed resistor will force a permanent "high" condition, which will result in incorrect fueling in the "low" range of the fuel map. If closed loop is running properly, the ECU can compensate for some of this but only up to +/- 30%. Again, you'll get weird behavior at low speed but VTEC will feel fine.
Finally, we're starting to see the fuel pressure regulators go bad on the early cars. This will cause the same symptoms, but not throw a code.
A few things to note:
- A strong gas smell is not normal and is an extremely dangerous situation. I would ventilate the work area and check the fuel system for leaks before starting the car again. Look at the fuel line fittings on top of the filter and on the fuel rails. Remove the injector covers and inspect each injector at the fuel rail, looking for traces of fuel on the top hat and at the intake manifold port. It is common for the O-rings on top of the injectors to get pinched on the sharp edges of the fuel rail holes when changing the injectors. Acura did this on my 91 and it caused a very strong gas smell. It's possible the mechanic who assembled your engine had no idea what he was doing and he cut an O-ring.
- The 06164-P0A-000 fuel injectors are not the right injectors for the 30L engine. They are 270cc flow rate, which means that they are delivering the wrong fuel (too much) at every single point on the fuel map. Again, the ECU can compensate a little, but not enough. I would have your OEM 240cc injectors cleaned at RC Engineering and then swap them. You don't need bigger injectors in the NSX unless you have cams and/or a displacement increase. If you do, you'll need to go with an aftermarket ECU solution.
- Given the mileage and questionable build history, I agree with @Old Guy that a compression test and valve clearance measurement might be in order.
I was also thinking that the 06164-P0A-000 were incorrect; but, some application lists do reference them for the C30 engine. The hazards of not purchasing from a reputable / knowledgeable source. The fact that the problems pre date the injectors would suggest that the injectors are not 'causal'; but, clearly need to go. Given the higher flow rate I am a little surprised that they are not triggering a fuel mixture out of range error. However, given what the ECU appears to be doing with error codes (disappearing at start up) perhaps something is up with the ECU.
The O2 sensors are presumably new so I kind of ruled out a sensor failure. However, the 1 and 2 codes do indicate a persisting issue of some kind with the sensors or a fuel mixture issue or a wiring issue or an ECU issue. With the info at hand can't be definitive about anything until stuff is ruled out like incorrect fuel injectors and fuel pressure issues.
I thought the limits on fuel trim were +/- 20%; but, that might be the error limit for setting a DTC on the OBDII cars and the actual trim limit is higher.
The O2 sensors are presumably new so I kind of ruled out a sensor failure. However, the 1 and 2 codes do indicate a persisting issue of some kind with the sensors or a fuel mixture issue or a wiring issue or an ECU issue. With the info at hand can't be definitive about anything until stuff is ruled out like incorrect fuel injectors and fuel pressure issues.
I thought the limits on fuel trim were +/- 20%; but, that might be the error limit for setting a DTC on the OBDII cars and the actual trim limit is higher.
- Joined
- 1 December 2023
- Messages
- 48
Alright sounds good, I was thinking that I would have to scan codes while they appeared on cluster.so confirms only codes 1 and 2.The Check engine doesn’t come up all the time,only when I full throttle to pick up speed at higher MPH if that makes sense (funny enough only noticed when I’m on the freeway)
I just got the loan a tool from autozone for fuel pressure testing will get it done this evening.Do you have any tips when checking the fuel pressure or is it straight forward if I follow from the service manual?
I just ordered a new fuel pump resistor and will be replacing when it arrives.will check on wiring as well
I had just replaced my o2 sensors and pulled the clock fuse to reset codes about 1000 miles ago.FPR was also changed with New OEM.CEL still occurred after.Is it possible could be something wrong internally with ecu?
My injectors and fuel filter have no leaks from when I checked them and installed them .maybe could be a micro leak somewhere?Its weird because I only smell gas in areas where intake and throttle body are located.if I sniff around fuel rail and fuel filter I don’t get a smell.I happen to have a smoke machine is there anywhere on fuel system where I can attach it to find a potential leak?I will be using these wrong injectors for now until I can send my oem to be cleaned.or maybe I will just put my oem ones back now.
Will report back when I’m done with the fuel pressure testing .and checking fuel pump resistor connections
I just got the loan a tool from autozone for fuel pressure testing will get it done this evening.Do you have any tips when checking the fuel pressure or is it straight forward if I follow from the service manual?
I just ordered a new fuel pump resistor and will be replacing when it arrives.will check on wiring as well
I had just replaced my o2 sensors and pulled the clock fuse to reset codes about 1000 miles ago.FPR was also changed with New OEM.CEL still occurred after.Is it possible could be something wrong internally with ecu?
My injectors and fuel filter have no leaks from when I checked them and installed them .maybe could be a micro leak somewhere?Its weird because I only smell gas in areas where intake and throttle body are located.if I sniff around fuel rail and fuel filter I don’t get a smell.I happen to have a smoke machine is there anywhere on fuel system where I can attach it to find a potential leak?I will be using these wrong injectors for now until I can send my oem to be cleaned.or maybe I will just put my oem ones back now.
Will report back when I’m done with the fuel pressure testing .and checking fuel pump resistor connections
The ECU stores error codes in the ECU memory. I can't remember exactly how many it will store; but, it displays them in the order of newest to oldest. However, that assumes that the ECU 'keep alive' power is supply is working. If you are out driving and the CEL come on you should be able to turn off the car and then turn the car back on and the CEL will normally stay lit up indicating a stored error code. Even if it doesn't stay lit up the code should be stored in the ECU. After you turn off the car you should be able to trigger the display of the stored codes by jumping the SC connector and turning the ignition to run. The stored codes should stay in the ECU until you reset them by pulling the clock fuse or your battery goes dead.
The smell of gas in the engine compartment is not normal; but, without more details can't comment on what might be wrong. When you do the fuel pressure test, once you shut the pump off the pressure should stay constant or drop very slowly. If it drops fast then you have a leak some place, a faulty check valve in the pump or a fuel pressure regulator problem.
If the problem existed prior to installing the new injectors then it is unlikely to be the new injectors.
Honda does not publish a spec for the fuel pump resistor; but measurements by Prime members indicate about 0.73 ohms for early cars and 0.55 ohms for later cars. I don't know what the change date is. Check the wiring on the fuel pump resistor as the resistor gets hot and the wiring can deteriorate resulting in a poor connection to the fuel pump. Some details here:
- Joined
- 1 December 2023
- Messages
- 48
For those injectors I had actually seen them on amayama as replacements that’s why I purchased them.I believe it said that the original injectors are discontiuned
Ok, this is helpful. I'm actually a fan of the "sniff" method to find fuel leaks because the smell is so strong. If it's around the throttle body and intake, there are really only two places to smell gas. First is the fuel line that connects the front and rear fuel rails. It runs under the intake manifold cover. If your fuel lines are original, you might have a small crack in the hose or the crimp fitting. Second is the PCV system. If the PCV valve is clogged/stuck, the oil vapor will back flow through the rear head line into the rubber throttle body bellows tube. That can case a gas-like smell (more like used motor oil to me). I would pull off the intake manifold cover and smell the hoses, especially near the crimp fittings.
Edit- interesting note on the injectors. I believe they did spec the 270cc units for certain 1995+ 3.0L cars, but we don't have the fuel maps for those cars, which were certainly adjusted for the extra flow. 91-94 NSX use the 240cc and fuel maps for that flow rate. You CAN run the 270cc on the early cars, but it might not run totally 100% fine- the ECU will be fighting the injectors in closed loop all the time.
- Joined
- 1 December 2023
- Messages
- 48
Fuel pressure was checked and everything looks like it’s in spec.did as specified in service manual .idle with FPR hose disconnected 50 and connected 40.I had my pops with me and he was saying that gas smell towards the intake/throttle body area smells more like a exhaust leak.if narrowed it down to fuel pump resistor and possibly exhaust leak (if this would affect anything ).compression will also get checked if these 2 options fail.anything else to check over ?
I went through this a while back on my C32. When it comes to injectors on the NSX, the on-line Acura parts system is, to be polite, confusing. Right now its doubly confusing because the on-line system in the US has had all injector part numbers deleted. Although, even Amayama is confusing. The C30A gets an additional confusion factor because they list 4 injector numbers and sort them differently depending on whether the car is an auto or manual.
All Honda injectors start with 06164 so I will drop that from the reference and just use the last two sets of numbers.. As best as I can sus out for the C30A, the original injector might have been PT3-A00. The info I found on flow rates for this injector are about 245 cc/min. This is out of production; but, Amayama does say that P0A-000 "most likely will fit instead" which is not quite the same as saying it is an exact fit. As far as I can determine P0A-000 has a flow rate around 270 cc/min. For the later auto box C30A cars with OBDII in North America (1995+) the US websites list P0A-A00 as the replacement injector and as far as I can determine it has a flow rate of around 250cc/min. This would seem to be a closer match to PT3-A00.
The Axx in the final three numbers in the Honda system typically means a North American part; but, not always. They don't always show up on Amayama (which generally does not cover North American exclusive parts) unless it is shared with other non NA cars so that may be why the P0A-A00 is absent from Amayama. P0A-000 was used on some non North American variants of the NSX and it was used on a lot of K series engines which is why it is a valid North American part number; but, not valid for the NSX in North America. That little bit of mystery may explain why it shows up on some C30A parts listings.
Assuming this is a North American spec car which still has a C30 engine and ECU it would seem that the P0A-A00 would be a more exact replacement than the P0A-000; however, as @Honcho notes, the discrepancy in flow rates is less than 10%. The 10% discrepancy will likely be manageable when the car is in closed loop operation. You said:
Short answer. Your injectors are not 100% correct; but, are not likely the cause of the problems you describe. Getting the original injectors cleaned would be a good idea. When you replaced your injectors I hope you replaced all the O rings and crush washers and lubed then up with silicone grease during assembly? You might have a slow leak at an injector which disappears as soon as the rail loses pressure. Did you do a pressure decay test when you had the fuel pressure gauge?
Your fuel pressures look OK so I expect that the fuel pump resistor is not defective or the cause of your problems; but, if you have a new one on order replace it to definitively rule it out as a cause.
I am still thinking that something is fishy with your CEL indication. Normally when an error occurs that causes the CEL to light up, the CEL will light up each time you start up the car and will not disappear until you do a reset. Are you actually getting 1 short blink, pause and then 2 short blinks pause and then a repeat indicating error codes 1 and 2 or are you getting continuous blinking? I believe that continuous blinking I believe that the ECU is in back-up mode. The 1991 service manual says "When the Check Engine light and the self diagnosis indicator are on, the back-up system is in operation. My problem is that I don't know what the self diagnosis indicator is. I have OBDII. Maybe somebody else with an early car can advise on this self diagnosis indicator.
If the ECU is going into back-up mode (as opposed to fail safe mode) that usually indicates a fatal ECU error. When the CEL comes on does it stay on until you stop and restart the car at which point it might drop out of back-up mode until you encounter the conditions causing back up to occur? In 13 years of ownership I have never heard of an NSX ECU entering back-up mode.
All Honda injectors start with 06164 so I will drop that from the reference and just use the last two sets of numbers.. As best as I can sus out for the C30A, the original injector might have been PT3-A00. The info I found on flow rates for this injector are about 245 cc/min. This is out of production; but, Amayama does say that P0A-000 "most likely will fit instead" which is not quite the same as saying it is an exact fit. As far as I can determine P0A-000 has a flow rate around 270 cc/min. For the later auto box C30A cars with OBDII in North America (1995+) the US websites list P0A-A00 as the replacement injector and as far as I can determine it has a flow rate of around 250cc/min. This would seem to be a closer match to PT3-A00.
The Axx in the final three numbers in the Honda system typically means a North American part; but, not always. They don't always show up on Amayama (which generally does not cover North American exclusive parts) unless it is shared with other non NA cars so that may be why the P0A-A00 is absent from Amayama. P0A-000 was used on some non North American variants of the NSX and it was used on a lot of K series engines which is why it is a valid North American part number; but, not valid for the NSX in North America. That little bit of mystery may explain why it shows up on some C30A parts listings.
Assuming this is a North American spec car which still has a C30 engine and ECU it would seem that the P0A-A00 would be a more exact replacement than the P0A-000; however, as @Honcho notes, the discrepancy in flow rates is less than 10%. The 10% discrepancy will likely be manageable when the car is in closed loop operation. You said:
If you did your fuel pressure tests after start up on an engine that was not up to operating temperature it is likely operating in open loop and the larger injectors will result in an engine running rich. The catalytic converters can normally clean that up; but, depending on circumstances such as how tired the cats are this can result in the exhaust having that old school 'choke is stuck on' stench which is what you might have been smelling.
Short answer. Your injectors are not 100% correct; but, are not likely the cause of the problems you describe. Getting the original injectors cleaned would be a good idea. When you replaced your injectors I hope you replaced all the O rings and crush washers and lubed then up with silicone grease during assembly? You might have a slow leak at an injector which disappears as soon as the rail loses pressure. Did you do a pressure decay test when you had the fuel pressure gauge?
Your fuel pressures look OK so I expect that the fuel pump resistor is not defective or the cause of your problems; but, if you have a new one on order replace it to definitively rule it out as a cause.
I am still thinking that something is fishy with your CEL indication. Normally when an error occurs that causes the CEL to light up, the CEL will light up each time you start up the car and will not disappear until you do a reset. Are you actually getting 1 short blink, pause and then 2 short blinks pause and then a repeat indicating error codes 1 and 2 or are you getting continuous blinking? I believe that continuous blinking I believe that the ECU is in back-up mode. The 1991 service manual says "When the Check Engine light and the self diagnosis indicator are on, the back-up system is in operation. My problem is that I don't know what the self diagnosis indicator is. I have OBDII. Maybe somebody else with an early car can advise on this self diagnosis indicator.
If the ECU is going into back-up mode (as opposed to fail safe mode) that usually indicates a fatal ECU error. When the CEL comes on does it stay on until you stop and restart the car at which point it might drop out of back-up mode until you encounter the conditions causing back up to occur? In 13 years of ownership I have never heard of an NSX ECU entering back-up mode.
Similar threads
