Problem after VTEC engagement and shift

jordonking · Post by **jordonking** » Mon Mar 05, 2007 9:12 pm

Hello all. Been awhile since I've posted, but ran into a little problem. I have a H22a w/ P28 s300. Awhile back I accidentally overwrote my main Configuration with one I downloaded. I have a wideband so I tuned the fuel tables in the map that I downloaded. The problem was that whenever I would hit VTEC I would engage clutch, shift gear, and step back on throttle. As soon as I would step back on throttle it would bog down and not want to go.

I tried everything and couldn't fix problem. So recently I started with a new preinstalled map that came w/ s300 (prelude map) and tuned lo cam fuel maps. Seems OK. Then today I turned on VTEC to tune Hi cam lobes and lo and behold same dang problem. Falls on it's face after I hit VTEC, shift, and back on throttle. I can let off of throttle a little and then it will eventually start to run good again, but as soon as I hit VTEC again same thing :-(. Attached are the map I running and datalog of problem. Any help would be greatly appreciated!!! :D

deafy · Post by **deafy** » Mon Mar 05, 2007 10:55 pm

Check your oil. If your oil level is very low, the VTEC oil pressure switch will affect vtec like that. If your oil level is fine, uncheck the VTEC oil pressure switch and try a "run." If the problem persists, its in Hondata's hands.

Preccord00 · Post by **Preccord00** » Tue Mar 06, 2007 11:32 am

fix your fuel map, if you don't fix your 2nd table you're liable to blow somthing up, you're going from 20% to 40% the second you hit vtec, flooding your cylinders with TWICE the amount of fuel prior to being in vtec.

you're getting shoved all over the place because your engine can't burn that much fuel at once causing the combustion to be partial.

Doing this often enough you can damage somthing.

Look at your fuel map for the 2nd fuel table, it's TWICE what your 1st table is, I would suggest highlighting the entire 2nd table and reducing it in 10% incriments untill it's close to your primary table.

try my calibration and tune off of that, I have a JDM H22a, although I have a Golden Eagle IM, so you'll have to tune the IABs for yours, and I probably have a ton more air flow than you since I've got CAI, DC headers and skunk2 cat back, but I at least have a basic tune. I'm using 280cc injectors too, so adjust as necessary.

jordonking · Post by **jordonking** » Tue Mar 06, 2007 9:17 pm

Did oil change, reduced fuel in Hi cam lobe fuel map, unchecked VTec oil pressure and problem persists. I guess I should expand on my setup. I have a JDM H22a 9.2:1 Pistons, 550cc injectors, eliminated IAB's. Air intake, header, and catback exhaust. When VTEC is engaged air/fuel shows to be 12:1 then after shift and back on throttle injectors just stop and air fuel is 22:1. For some reason it's just like it cuts injectors after VTEC engagement and shift. I let off a sec or 2 and then it's ok. Driving me nuts. I'll look at your map Preccord00. Thanks for all the help guys. Any other suggestions?

Preccord00 · Post by **Preccord00** » Tue Mar 06, 2007 9:39 pm

fuel is the only thing that makes sense to me by looking at that datalog, you can see in the datalog that VTP is on and instantly your duty cycle jumps from 20% to 41% and your injectors go from 4.9ms to 9.7ms, half a second later your AFR jumps from 17.1 to 10.8.

All of these are symptoms of an extremly rich fuel map, I also noticed you run slightly lean on your primary fuel table according to your wideband, but that has nothing to do with this issue.

jordonking · Post by **jordonking** » Wed Mar 07, 2007 4:52 pm

Well today I modified Preccord00's map that he uploaded just enough to see if it would fix problem. Unfortunately problem still there. Here's an upload of the modified map and a datalog after running it. Do you guys find anything strange with the MAP and throttle readings after shift from 2nd to 3rd?

Preccord00 · Post by **Preccord00** » Wed Mar 07, 2007 5:09 pm

ok, I see what you're talking about now, you can see your ignitian timing starts going a little off trying to adjust to whatever's going on.

I also saw the strange MAP reading of 6549kPa.

I'm not exactly sure what could be causing it if oil pressure isn't affecting it, fuel isn't an issue, possibly distributor timing, hmmm.

I'll think about what it could be, right now I'm lost to exactly what it is, none of the sensors I have reading are, wait... how did you disable your IABs?

Preccord00 · Post by **Preccord00** » Wed Mar 07, 2007 5:14 pm

turn off full throttle shift, my car is set up for it, but yours is not, so you're going to hit a rev limiter at 6k.

Another thought, try running it in open loop.

jordonking · Post by **jordonking** » Wed Mar 07, 2007 9:00 pm

I'll disable full throttle shift tomorrow, but I know it'll still do it. The IAB's I just removed IAB Plate and threaded studs down further. As for the MAP thing as well. Even besides the glitch if you'll notice my throttle is at like 80% after the shift and the MAP is at like 20" . I know it's a very small time frame, but if my throttle is open 80%, 20" doesn't seem possible or am I thinking about this wrong. I thought maybe a kink in my vacuum line to sensor, but it looks ok. Maybe MAP going out? :?

jordonking · Post by **jordonking** » Wed Mar 07, 2007 9:01 pm

Oh yeah and I've already tried running open loop as well. I also just noticed that the glitch when the MAP sensor shows 1904.4 is exactly when the computer shifts from VTEC fuel map to normal fuel map. It's gotta be something to do with that. Maybe ECU going out? I guess I'll do another pull tomorrow and see if the same glitch shows up.

Preccord00 · Post by **Preccord00** » Thu Mar 08, 2007 1:46 pm

ya, I see what you're talking about.

did you actually have the throttle open to 80-90% when the MAP was reading 20 or was the TPS reading wrong?

that's just weird.

let me know what you get tonight and I'll see if I can figure out a little more.

I'm starting to think you might have some wires crossed or somthing.

jordonking · Post by **jordonking** » Thu Mar 08, 2007 5:03 pm

Took another datalog a little while ago. The weird 1904.4" Vacuum reading did not appear this time, but the high MAP sensor reading with throttle open did. And the TPS is correct. Also I've had this computer in my car for awhile. And it ran great for a long time. VTEC engaged correctly every time. I haven't changed any of the wiring. Driving me nuts!

Vlude · Post by **Vlude** » Thu Mar 08, 2007 5:35 pm

Hi , I would say you have a problem with a map sensor. After shifting tps is 90 ,but map reads relatively high vacuum,while in fact you have low vacuum. Thats causing injectors to inject less fuel and to make extremely learn mixture. Even looking throuhg the all graph you can see that the map sensor gives strange readings.

deafy · Post by **deafy** » Thu Mar 08, 2007 8:47 pm

I'd like to see a dyno graph when you get this all working and tuned up. I'm an H22 guy myself and fairly interested in an H22 ITB setup sometime in the future.

jordonking · Post by **jordonking** » Thu Mar 08, 2007 8:57 pm

Yeah that's what I was leaning toward. I'll try a MAP sensor tomorrow if I don't go looking at s2000's. I'm 6'2" and was wondering how comforatable I'ld be in one. I'll probably take the H22 and get my ignition tuned on the dyno so I'll get a print out. I've actually been thinking of yanking the head and putting some 11.5:1's in and a set of ITB's. Can't make up my mind? Boost.... Hi compression... I don't know!