cmwalker

hey guys fresh rebuild motor now car wont hit vtec. almost like it sets a rev limit to exactly what vtecs set too. if i disable vtec in the s300 it will rev forever just slow as *****.... what could cause such a rev limit, i kno vtec can mechanically work because i quickly hooked a 12v source to the vtec solenoid and it engaged vtec almost stalling the car because the computer was not switching to highspeed map.... please help if you have ideas!

cmwalker

no check engine lights, if i set vtec to 6500 it will rev limit at 6500 if i set vtec too 5700 it will rev limit there, if i partial throttle it will redline to 8k wat the limit is set too for now.

el crapitan

check for codes. regardless of an illuminated cel.
also, may want to check oil pressure with a gauge

cmwalker

ok so i went out today and bought a oil pressure gauge. i checked for oil pressure at the 10 mm bolt on the front of the head. at idle w/ no vtec i get 0psi when i manual connect the vtec solenoid to 12v it engages vtec and i get about 70psi 4k rpm.

cmwalker

you can tell vtec engages because it runs like **** and sounds different. has anyone ever had this happen?

fcm

Wait, say what, "car wont hit vtec" and "you can tell vtec engages"???

Which is it vtec does not hit, [not engaging?] or vtec does engage?

Or do you mean vtec engages, but engine runs like "****" when the vtec engages?

Have you confirmed valve timing is correct?94

cmwalker

i manually engaged vtec at a stand still by giving the solenoid 12v. i did this to check for oil pressure at the 10mm port on the head, and i did this to see if mechanically the car is able to hit vtec....but when i drive the car hits a rev limiter at w/e vtec is set at.

el crapitan

remove the oil pressure sender and check oil pressure there. at idle, and at 3k. there's a spec for both

cmwalker

i did my oil pressure is perfect. i get about 20 psi at idle and over 75 at 4k

el crapitan

alright, good. did you check for codes?

robotnix88crx

re-tune the s300, I had the same issue on mine,

el crapitan

would be nice if you had a friend with an ECM that you could try out. or if the s300 has the option to return to stock. regretfully, i'm not all that familiar with tuners

cmwalker

can you explain your situation??

Brraapp

did you check your oil level? had a friend have the same problem and it was just his level,

cmwalker

yah its a brand new engine doesnt burn or leak lol oil is perfect....first thing i checked.

el crapitan

what all is done to this engine? more details, please.
and again, did you actually CHECK for codes?

cmwalker

yes i checked for codes by jumping service connector...nothing.....i also have hondata s300 and no codes show up.


its a 95 gsr block, ls crank n rods, p30 pistons, b16 head, s2p2 cams, pro series valve springs and retainers, i have about $1900 worth of machining, knife edged crank, balanced to 10 grand, arp everything. hondata s300


thanks for your time this ***** crazy, im thinking its an input to the computer because i put my ecu in my friends car and it popped vtec. im thinking about using hondata to disable every sensor that has stops vtec from engaging and seeing what happens.

DeCePtEgRa

Jeez El can you ask to check codes one more time I don't think he read it the first times lol. No surprise you don't know about tuners lol

I'll assume there is ohms testing for the vtec solenoid. I'll check Monday on alldata and Mitchell or there may be info found on Google.

el crapitan

are you baked? he clearly stated in the first post that the solenoid engages when he hard wires it. the solenoid is not the problem. but i guess you'll just have to wait till monday to have alldata tell you what to do.


OP, check your vtec solenoid screen. make sure it's clean.

GSR360

make sure oil, speedometer, etc are all good

cmwalker

ect is new and tested its good, speedo works as far as the instrument cluster... and motor is on its 3rd oil change, not even 300 miles. level is good no leaks.... im thinking it has to be an input to the computer.... how many inputs does vtec require?

el crapitan

check the screen, bud. it's common.
if you're not throwing a code for an input, i wouldn't look there first.
vss, tach, map, tps. just to name a few though

cmwalker

screen is clean. i took it off n cleaned it, one of first things i did....but just because there is no check engine doesnt mean one of the inputs isnt wired wrong or something weird. its obd1 the ECT can be wired backwards and the car wont throw a code. so i need my friend to come over with his integra and ill go over every wire color fakk

el crapitan

it shouldn't matter ifthe ect is wired backwards. it's just a thermistor. it doesn't know which side is ground or positive. it doesn't need to. it just varies resistance with temperature.
but if you have any doubts about your wiring there, then yes, having another vehicle to compare off of would be ideal

DeCePtEgRa

hey bud check to see if you throwing a code A , maybe high resistance isnt allowing it to open all the way. Were not all perfect like you ehh forgot Canadians think there better than everyone else must be the French in you.