Rpm issue(very wierd)

holset hatch · Post by **holset hatch** » Sat Jun 14, 2008 8:33 pm

I took my car to the drag strip on fri night, and it developed a strange problem that i need some ideas with.
setup is as follows;
91 civic hatch
built ls/vtec @ 12lbs
hx35
tial 44mm
precision 600hp intercooler
walbro 255hp/1000cc inj
S300
obd-1 conversion & new distributer

street tuned on 91oct
it was tuned back in may with the help of a friend, afr's were a solid 11.5:1 under boost, pulled hard and clean through the gears, no issues.

i took the car out to the local fri night legals;

first run shifting into third car hits what feels like lean cut, let off coast for run. second run this time shift to second, hits what feels like lean cut right away again. let off, i can rev up to 2g then cut till 1g then let me rev till 2g again(a painfully slow exit from my lane)

when free-reving the car the rpm point at which i can free-rev to changes. the rev's will also not respond to quick changes. if i rev the car, let it drop then rev again on the way down, nothing will happen right away... the response is very delayed.

when driving the car i have till 1800-2000rpm before it cuts me. makes for a long ride home when your powerband is 1000-2000rpm, lol

any ideas? i am leaning towards something ignition, possibly faulty coil, maybe tps? i had msd wires, switched to ngk no difference. the s300 seems fine has green lights?
tried disabling launch control, lean cut/boost cut, etc.. and no change in how it responds.

car idles fine, doesnt die when it cuts me either and no cels???

midoriek4 · Post by **midoriek4** » Sun Jul 13, 2008 8:30 pm

having the same issue here....the limiter stays on and will not come off.....

Post by **Hondata** » Mon Jul 14, 2008 8:29 am

If you are sure that you're not hitting the boost limiter, then the problem is noise from the distributor. We've seen the problem with after-market distributros, usually occurs at 9500 rpm, and rev limits the engine as you described.

Post by **Spunkster** » Mon Jul 14, 2008 10:11 am

Without the calibration it is hard to see what is really goign on with the datalog

midoriek4 · Post by **midoriek4** » Mon Jul 14, 2008 12:01 pm

Hondata wrote:If you are sure that you're not hitting the boost limiter, then the problem is noise from the distributor. We've seen the problem with after-market distributros, usually occurs at 9500 rpm, and rev limits the engine as you described.

i made sure in the data log that we are not hitting any boost cut/boost limiter....i will look more into the distributor.....thanks....

DaN

midoriek4 · Post by **midoriek4** » Fri Jul 18, 2008 8:35 am

would you reccomend running some shielded wire for the signal wires from the dizzy to the ECU???

Post by **Hondata** » Fri Jul 18, 2008 8:41 am

The factory wiring to the distributor is shielded.

What you need to look for is anything which is not stock - distributor, plug wires, plugs, ignitor, coil. In the past we've seen problems mainly with plug wires, non-resistor spark plugs & after-market distributors.

midoriek4 · Post by **midoriek4** » Tue Jul 22, 2008 2:21 pm

this might sound off the wall but does engine temp have anything to do with noise interference....i only ask cause it seems we come across this problem with temps are higher than 180.....

Post by **Spunkster** » Tue Jul 22, 2008 3:43 pm

temp should have nothing to do with it unless you have aftermarket ignition components that are affected by heat