kikkomon

I recently purchased a 2006 formula red ap2 with 5300 miles on it. There is a slight sort of jerk hesitation between 2-3k rpm. It is intermittent. I've read everything I could find by googling and the search function but I cannot seem to find a post with a solution. Only finding a lot of people with the same issue. It is not heat soak. I checked my MAF but I don't think the zip tie TSB applies here. It's also only part throttle. The car just jerks back for a split second and then revs up just fine. This also isn't lugging from being to low in the rpms. I've seen replies like that in other posts. It's just a quick sudden loss of power that lasts 1/2 a second and then runs perfect. I'm sure the car sat a lot. Had to have been with this mileage. Engine compartment looks like new. In fact the entire car looks showroom new. $22k and it was mine This is my 5th s2k and hopefully my final one. If anyone has any ideas or can point me to a post that I have over looked i'd appreciate it very much so. Here is a post on this forum with many people with the same issue and no solution.

https://www.s2ki.com/s2000/topic/871...m/page__st__75

Slowcrash_101

Could be spark plugs, could be O2 sensor, could be TPS, could be a problem with the fuel system, or a combination of all those things in varying degrees.

redwing497

kikkomon, I was the OP in that thread you linked. I've had my car now for over 3 years. What I found is that, in warmer weather, this is what happens. Especially in stop and go type of driving. It doesn't even have to be that hot out. I honestly believe it's just the nature of the car. I didn't do anything about the hesitation and haven't had a single problem.

What's interesting, though, is in COLD weather this issue basically disappears. It barely happens to me (if at all) in the wintertime. Like I said before, I think it's just a characteristic of our DBW cars. I can't comment on earlier model years, unfortunately. IMO, there's nothing wrong with your car at all.

shind3

I have the EXACT same problem. I replaced spark plugs, O2 sensor and adjusted my valve lash. I thought increasing the exhaust clearance a bit helped this situation on my car but I am not sure it's not a placebo effect.

I guess the last thing left to do is swap out the throttle body? Or is it just the TPS sensor going?

kikkomon

So today I decided to add a fuel system cleaner, and clean the map sensor with some map sensor cleaner. I won't know the results of the fuel system cleaner for a while but cleaning of the MAP sensor didn't change anything. I'm still getting the intermittent hesitations about 2.5k rpm and sometimes about 3.5k. It's always in the same spots on the gauge. I then thought since the car sat so long the TPS may have a bad spot from weathering. I looked for the TPS on my throttle body but did not find one. I'm assuming DBW doesn't use them. Please correct me if i'm wrong.

http://imgbox.com/MkfVcS9f
http://imgbox.com/H05OgSke

This is my 5th s2k and 1st one with DBW, I'm pretty sure that the hesitation isn't the nature of the DBW. Something small is just out of whack. I will hunt it down and let you guys know how I fixed it. Had the same issue on my 89 Mitsu Starion back in the day and after a couple weeks of searching I fixed it and posted it on StarquestClub.com.

shind3

yeah, i agree that this isn't normal. another thought was the pedal position senskr in the DBW module. is it sticking and then suddenly unsticking? but then why does it only happen in a narrow rpm range?

vtec9

https://www.s2ki.com/s2000/topic/813...or-signal-dbw/

kikkomon

Out of frustration, I went to the local Honda dealer to see if they could pin point the problem. I spoke with a service representative and he asked me if there were CELs. There aren't any so he went on to tell me that the technicians there don't know much about this car and without any CEL's i'd be chasing a ghost and wasting money. I did pop the hood while I was there and some random service guy was telling me stuff like they'd clean the carbon off my valves blah blah blah and I pointed to the IAT sensor and asked him what it was. He didn't know. I randomly pulled the plug on it and reinserted it. I left the dealer and low and behold I get a CEL. I ran to the autoparts store and bought a code reader. The code was P0113. IAT sensor. I checked the connector and it was in there right and snug. So I decided to pull the IAT out of my 06 Honda Element and try it in the car. It looked the same so what could it hurt right. There was a number etched in it which was different than the s2ks. I cleared the CEL and reset the ECU and off I went. The car exibited no signs of hesitation. I drove it around for another 10 minutes or so and didn't really notice much. I have to drive it around more to make sure it wasn't from the ECU reset. I then took my Honda Element out and there is no CEL to speak of. Only thing I can think is there might be a short in the plug or whatnot. Probably an after effect of cleaning my engine compartment. Sorry for the long post but I thought give you guys an update. I will be monitoring the condition through to the upcoming Honda meet in Richmond which I already purchased tickets.

kikkomon

So far so good. No more jerky hesitation. My advice to people with this issue it to buy a OBDII Scantool with live data. Here's a link. http://www.amazon.com/gp/product/B00...pf_rd_i=507846

Check for pending codes. Check the live readings your sensors are putting out. My IAT sensor was whack but didn't throw a code for a over a week.

kikkomon

Hesitation is back. Apparently had nothing to do with the IAT sensor. What could cause hesitation that disappears when you reset the ECU and comes back after couple hundred miles? The hesitation is in the exact same spots. 2.5k rpm and 3.5k rpm and in between those the torque doesn't feel right. Above those rpms she sings. Also I noticed the CDV has been removed. I tested this today by shifting it hard from 1st to 2nd. Makes me wonder if the odometer has been tampered with as well.