AP1 hesitation at 2.5k rpm
09-10-2018, 06:17 PM
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AP1 hesitation at 2.5k rpm
Hello. I'm a new member here but I've owned an AP1 S2k for around a year now. The past few months, I've ran into a few issues.
For around 9 months, the car drove great. A few months back, it started off as a multiple cylinder misfire. There was a rough idle every now and then that progressively got worse and happened more often as time went by. I though it might be the IAC, so I took it off of the intake and cleaned it with a bottle of carb cleaner, but there was no change. After joining this forum and reading a few threads on this issue, I thought it would be best to go with new fuel injectors, as the threads that discussed similar issues seemed to be solved by replacing the injectors. Not knowing for sure if it was the injectors or not, I looked on Ebay and decided to take a risk on a $44 part, and I purchased a set of these:
https://www.ebay.com/itm/4-Pcs-OEM-Fuel-Injectors-For-Honda-S2000-DOHC-F20C1-F22C1-S2K-AP1-AP2-2-0L-2-2L/162615441783?fits=Model%3AS2000%7CMake%3AHonda&has h=item25dca2b977:g:AA0AAOSwZs1Zgs94&vxp=mtr
I just changed the injectors about an hour ago, and now there is a new issue. The rough idle is completely gone, but there is now a hesitation or bogging down at around 2.5k rpm until around 3.5k rpm, that is only there in that rev range. It happens in both low throttle input, or WOT. It is pretty bad, and I'll have to be careful pulling into a street until this issue is fixed.
There was a very sticky black residue in the intake that I cleaned off as best I could to allow the rubber around the injectors to seal to the intake. The motor is going through around one quart of oil every 1k miles, so I believe this is what that residue was. I don't believe I knocked anything loose or accidentally disconnected anything, so I'm at a loss here trying to figure out how just changing injectors could "fix" the old issue and at the same time cause a new one. At one point during the installation, I dropped one of the injectors through the middle of the first and second intake runners, and I reached through some hoses under the intake to pick it up, but I didn't feel anything come loose or crack. I cleared the misfire codes, and I'm going to drive the car and wait to see what new codes it throws, then go from there, but if there are any suggestions, I'm open to hearing them.
If there is anything I can do to try to diagnose the issue further, please let me know.
Edit: I forgot to mention that the injectors that were replaced were branded the same as the injectors in the link above, with a "KEI HIN" on the plastic body of the injector. I'm not sure if these are OEM, or more likely, they were replaced in the past.
For around 9 months, the car drove great. A few months back, it started off as a multiple cylinder misfire. There was a rough idle every now and then that progressively got worse and happened more often as time went by. I though it might be the IAC, so I took it off of the intake and cleaned it with a bottle of carb cleaner, but there was no change. After joining this forum and reading a few threads on this issue, I thought it would be best to go with new fuel injectors, as the threads that discussed similar issues seemed to be solved by replacing the injectors. Not knowing for sure if it was the injectors or not, I looked on Ebay and decided to take a risk on a $44 part, and I purchased a set of these:
https://www.ebay.com/itm/4-Pcs-OEM-Fuel-Injectors-For-Honda-S2000-DOHC-F20C1-F22C1-S2K-AP1-AP2-2-0L-2-2L/162615441783?fits=Model%3AS2000%7CMake%3AHonda&has h=item25dca2b977:g:AA0AAOSwZs1Zgs94&vxp=mtr
I just changed the injectors about an hour ago, and now there is a new issue. The rough idle is completely gone, but there is now a hesitation or bogging down at around 2.5k rpm until around 3.5k rpm, that is only there in that rev range. It happens in both low throttle input, or WOT. It is pretty bad, and I'll have to be careful pulling into a street until this issue is fixed.
There was a very sticky black residue in the intake that I cleaned off as best I could to allow the rubber around the injectors to seal to the intake. The motor is going through around one quart of oil every 1k miles, so I believe this is what that residue was. I don't believe I knocked anything loose or accidentally disconnected anything, so I'm at a loss here trying to figure out how just changing injectors could "fix" the old issue and at the same time cause a new one. At one point during the installation, I dropped one of the injectors through the middle of the first and second intake runners, and I reached through some hoses under the intake to pick it up, but I didn't feel anything come loose or crack. I cleared the misfire codes, and I'm going to drive the car and wait to see what new codes it throws, then go from there, but if there are any suggestions, I'm open to hearing them.
If there is anything I can do to try to diagnose the issue further, please let me know.
Edit: I forgot to mention that the injectors that were replaced were branded the same as the injectors in the link above, with a "KEI HIN" on the plastic body of the injector. I'm not sure if these are OEM, or more likely, they were replaced in the past.
Last edited by balance s2k; 09-10-2018 at 06:23 PM.
09-13-2018, 04:35 AM
#2
They do not seem to be genuine OEM Honda injectors. This is a risk. What's your mileage right now? Have you ever checked your coil packs for oil residue on them? What spark plugs do you run? Does the car have any ECU mods/tweaks?
09-13-2018, 05:28 AM
#3
with any idle or misfire issues, I typically crack open the valve cover and do a valve adjustment- just to be sure. I had issues with my EM1 in the past and the valve adjustment helped.
darcy
darcy
09-14-2018, 10:42 AM
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I appreciate the replies.
I managed to get a little bit of time to work on the car today, and after some inspecting with a scan tool, I found that the it wasn't getting fuel. I swapped the injectors that were on the car previously, back on the car. The motor is running exactly as it was before I installed these Ebay injectors. It must be an issue with these injectors. I thought for $44 I'd risk it, but I guess it wasn't worth it.
Are the S2000 injectors proprietary to the S2000? If I must, I'll get new factory injectors installed in the car, but I'm not in the mood to pay around $150 each if I can avoid it.
To answer a few questions, the car has 230k miles and it ran like new, up until a few months ago. I hit VTEC a few times a day with no worries. I've adjusted the valves and replaced the valve cover gasket after doing so. I use Denso Iridium plugs, and have installed a resonated test pipe and a pair of sportbike mufflers. It's otherwise stock and in good condition.
The car was throwing these codes before I decided to replace the injectors:
P0300
P0411
P1457
P0304
P0303
P0302
P0301
A little bit of searching on this site seemed to suggest that the injectors would be a likely cause, but if they don't fix it, I'll move on to inspecting the secondary air pump and EVAP lines. Unfortunately, I don't have as much time to work on cars as I used to.
I managed to get a little bit of time to work on the car today, and after some inspecting with a scan tool, I found that the it wasn't getting fuel. I swapped the injectors that were on the car previously, back on the car. The motor is running exactly as it was before I installed these Ebay injectors. It must be an issue with these injectors. I thought for $44 I'd risk it, but I guess it wasn't worth it.
Are the S2000 injectors proprietary to the S2000? If I must, I'll get new factory injectors installed in the car, but I'm not in the mood to pay around $150 each if I can avoid it.
To answer a few questions, the car has 230k miles and it ran like new, up until a few months ago. I hit VTEC a few times a day with no worries. I've adjusted the valves and replaced the valve cover gasket after doing so. I use Denso Iridium plugs, and have installed a resonated test pipe and a pair of sportbike mufflers. It's otherwise stock and in good condition.
The car was throwing these codes before I decided to replace the injectors:
P0300
P0411
P1457
P0304
P0303
P0302
P0301
A little bit of searching on this site seemed to suggest that the injectors would be a likely cause, but if they don't fix it, I'll move on to inspecting the secondary air pump and EVAP lines. Unfortunately, I don't have as much time to work on cars as I used to.
Last edited by balance s2k; 09-14-2018 at 10:45 AM.
09-17-2018, 12:55 AM
#5
I appreciate the replies.
I managed to get a little bit of time to work on the car today, and after some inspecting with a scan tool, I found that the it wasn't getting fuel. I swapped the injectors that were on the car previously, back on the car. The motor is running exactly as it was before I installed these Ebay injectors. It must be an issue with these injectors. I thought for $44 I'd risk it, but I guess it wasn't worth it.
Are the S2000 injectors proprietary to the S2000? If I must, I'll get new factory injectors installed in the car, but I'm not in the mood to pay around $150 each if I can avoid it.
To answer a few questions, the car has 230k miles and it ran like new, up until a few months ago. I hit VTEC a few times a day with no worries. I've adjusted the valves and replaced the valve cover gasket after doing so. I use Denso Iridium plugs, and have installed a resonated test pipe and a pair of sportbike mufflers. It's otherwise stock and in good condition.
The car was throwing these codes before I decided to replace the injectors:
P0300
P0411
P1457
P0304
P0303
P0302
P0301
A little bit of searching on this site seemed to suggest that the injectors would be a likely cause, but if they don't fix it, I'll move on to inspecting the secondary air pump and EVAP lines. Unfortunately, I don't have as much time to work on cars as I used to.
I managed to get a little bit of time to work on the car today, and after some inspecting with a scan tool, I found that the it wasn't getting fuel. I swapped the injectors that were on the car previously, back on the car. The motor is running exactly as it was before I installed these Ebay injectors. It must be an issue with these injectors. I thought for $44 I'd risk it, but I guess it wasn't worth it.
Are the S2000 injectors proprietary to the S2000? If I must, I'll get new factory injectors installed in the car, but I'm not in the mood to pay around $150 each if I can avoid it.
To answer a few questions, the car has 230k miles and it ran like new, up until a few months ago. I hit VTEC a few times a day with no worries. I've adjusted the valves and replaced the valve cover gasket after doing so. I use Denso Iridium plugs, and have installed a resonated test pipe and a pair of sportbike mufflers. It's otherwise stock and in good condition.
The car was throwing these codes before I decided to replace the injectors:
P0300
P0411
P1457
P0304
P0303
P0302
P0301
A little bit of searching on this site seemed to suggest that the injectors would be a likely cause, but if they don't fix it, I'll move on to inspecting the secondary air pump and EVAP lines. Unfortunately, I don't have as much time to work on cars as I used to.
Please check your coil packs for oil residue if you haven't already. You may need to change the valve cover gasket and plug tube seals.
09-17-2018, 01:25 PM
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Yes they are proprietary. No other 4 cylinder Honda makes uses the same injectors.
Wow 230k miles! Reliability for years
Please check your coil packs for oil residue if you haven't already. You may need to change the valve cover gasket and plug tube seals.
09-18-2018, 12:49 AM
#7
This is good to know. Thank you.
My pleasure
It is impressive how well the interior has held up. The car still looks very well, and the motor ran very smoothly idling at around 1k rpm before this issue. I have no hesitation to drive the car and am enjoying the S2000 more than any other car I've owned. I'm used to driving BMWs and the simplicity and performance of this car is very appealing to me.
No doubt!
Will do. I replaced the valve cover gasket when I adjusted the valves some months back with a gasket set I bought from Honda, but I don't remember if it came with the plug tube seals.
My pleasure
It is impressive how well the interior has held up. The car still looks very well, and the motor ran very smoothly idling at around 1k rpm before this issue. I have no hesitation to drive the car and am enjoying the S2000 more than any other car I've owned. I'm used to driving BMWs and the simplicity and performance of this car is very appealing to me.
No doubt!
Will do. I replaced the valve cover gasket when I adjusted the valves some months back with a gasket set I bought from Honda, but I don't remember if it came with the plug tube seals.
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