suganuma

but ive got boost problems.....and weird ones at that

i have a profec B -
turned off - 7 psi
low boost - 10
high boost - 13

let me first give you the whole history of the past couple weeks....

took the car to the rocky mountain import nationals where in summary i ran a 15.5, 14.8, and another 15.5.
specifics can be seen on an earlier post https://www.rx7club.com/vforums/show...low+drag+times

there everyone thought it was clutch problems for the most part since times were so slow in general and it just wasnt pulling at the top. when i looked at the gauge during the run my boost was steady at 13. i had a crossthreaded leading spark plug which was in there crooked during the run which ive now gotten tapped and put in straight. i was running 13# at track.

this friday i get into the car and notice that im getting a 10-5-10 boost pattern where the secondary was very slow to come on (wasnt at full boost until 5k). a friend in the area (dr wankel) said hes always gotten 5# at transition since hes had the car and his times were fine at the drags (13.54 @106 with PFC and downpipe)

last night i took the car up to meet with dr wankel and go to this cruise spot up in denver. we found some vettes, a blown mustang, and a couple F-bodies cruising around together so we followed them around and ended up doing some racing. i raced the blown stang and was dead even with him after he jumped the start. i followed along with my friend as he raced a stock C5 and the vette pulled on me a car or 2 (friend pulled him).

later that night when accelerating from 1st i saw the revs go up, but i went nowhere - so i thought "ya, now my clutch is slipping"
i was on 13# the whole night.

on the way home i did some checks from 3rd and 4th @10#.
if i shift down so that revs are after transition it sticks at 10. however, if i shift down so revs are at 3500 or so and then go to WOT, it will SOMETIMES stick down in the 5# transition, jump around, and then decide to kick in the 2nd turbo. other times it goes 10-5-10 like it did on friday, other times it just sticks at 5.

SO....(damn this is getting long)

today i take it out. (hope i can remember this all correctly since its so inconsistent!!) look at boost gauge as im going through 1st and it goes 10-5- and then makes its happy *** way to 0 jumping around a lot as it gets to redline. if im in 1st after transition it hits 10. if i go partial throttle through transition and then hit it after 5k it hits 10. 2nd,3rd,4th gear is fine if after transition. 2nd gear one run went to 10 and didnt ever drop at transition. 3rd gear from 3500 went to 10#, 5# at transition, jumped around, kicked in 10 finally at 5500-6000 and then slowly dropped to 7 or so as i got to redline.

ALL gears are fine if i hit it after transition i get 10 as well as primary is fine at 10. its just if i go through transition things get all crazy.

ANY CLUES??!?!?!?!?!!!!!

im so pissed and frustrated right now and SOOOOOO ready to go single once i get the money, but id like to correct SOME of this before i get the money.

i took out spark plugs yesterday to make sure they werent completely BLACK yesterday as well as looked at my O2 sensor since it was giving a 0.00V reading. So when i did that i checked all IC piping and its fine as well as what i could see of the lines under the UIM, but i didnt take it off. i did check the resistance of the solenoids and got
30.5 ohms for wastegate solenoid
30.0 ohms for precontrol solenoid

i appreciate ANY help any of y'all can provide.....im at a loss right now and have a headache.....

OH....and sorry for the short novel - i didnt know how to sum it all up

suganuma

when i tried to start the car today the battery was dead as a doornail......
got a jump....let it warm up a bit before driving, but when i started driving it was bucking and the ABS light kept flashing. so i pulled the fuse and then everything started working fine again. my battery voltage is .5 volts lower than normal i noticed after driving for a while.

also, i apparently have a vacuum leak somewhere....i just switched boost gauges from autometer to apexi. apexi said when i first put it on that i was getting 14mmHg which seemed about right seeing as how i am ported (other people say they get similar readings)
yesterday and today i noticed its crept closer to being anywhere between 11-13 ( i know im not THAT ported). any ideas thataways?? i dont see anything right off thats disconnected.

thanks

suganuma

no help.....no love

Nic

7sweetie

i could help you, in more ways than one, lol, joke

GoodfellaFD3S

iTrader: (213)

I'll give you a hug...

ok, maybe not. I'll leave that to 7sweetie

If RP is stumped, perhaps shoot Dave at KD an email (kdrotary@enter.net)?

He's always been great about getting back to me quickly. Good luck reaching him on the phone though :p

suganuma

well im replacing all of my vacuum lines, and checking a lot of things while i have the UIM off hopefully this weekend if the lines get here in time. if everything is still jacked after that ill give em a call.....

Nic

cewrx7r1

iTrader: (2)

Go to http://home.iSTAR.ca/~dvandit/ and follow the trail to turbo diagnosis. They also
have a good control system diagram.


My NA street ported 83 12A would run 14.6.

KZ1

well you clutch does sounds like it is toast, but you obviously have more problems than that. You said it slipped in 1st gear, usallu clutch will slip more in higher gears IE 5th at 90mph at WOT. Maybe you were just spinning tyres?

Does sound like you have vacumm leak, check your vacuum tank for storage ability first. could just be a check valve. ABS light? that is strange. Maybe your car has been possesed by the Taliban.

suganuma

wasnt spinning tires.....as i said (maybe all of the craziness above got you confused), but the boost in first gear after transition (at 5#) "was making its happy *** way to 0 as i got to redline"

so thats whats up with that. but ya, in the top of 4th and then in 5th gear driving the car up to CO when i was making good boost and everything else was running right i could see it slipping at 140 when i tried to do a top speed run on a lonely straight as hell 2 lane TX highway.

im going to go ahead and order all 5 of the check valves new just so i dont run into any problems when im doing my hoses except for maybe diagnosing a bad (and lazy) wastegate and/or precontrol solenoid.

theres a hose kit on its way to me right now. hopefully it gets to the base package stop by friday so i can get this done over the weekend.

SPOautos

Ok, take you intake off so you can see all the little vacume lines and such around the Y pipe. Make sure the crv(looks like the bov but its toward the back) and all those vac lines are nice and tight on thier nipples.

There is a black box in front of the intake manifold, remove it (you might have to take the tower strut brace off if you have one) so you can see up in the manifold better. There are 2 silinoids (sp?) standing straight up toward the left (drivers side) of the opening under the manifold. Shine a flashlight back in behind them and all around under there as much as you can and look for a poped off hose. I found a hose that was poped off right around there and didnt even have to pull my manifold to get to it. That hose was making my transition fall to 0psi of boost and staying there.

The 2nd prob I was having was my IC pipe coupling between the Y pipe and crossover tube was ripped and I had to take it all the way off to tell because the rip was behind the hose clamp.

Here is the best thing you can do before taking off you manifold. Check all you IC pipes and couplings for cracks and rips by taking them completely off and instecting them. You cant check them good enough without removing them. Then take off you intake system and check out all the little vacume lines around the Y pipe along with the crv. Then shine a light under the manifold looking for poped off vacume lines.

If non of that helps you'll probably end up pulling the manifold and doing the hose job or something.

BTW - Do you have you BOV venting to atmosphere? If so, is it making its normal noises? When i had a IC pipe leak my BOV wasnt making noise because the boost was being vented out the rip in my coupling instead of the bov.

Damn, sorry this was so long!!!!!!

Later,

suganuma

stephen,

thanks for the advice, but ive already checked all of these things on saturday afternoon and found nothing wrong. obviously things got worse that night though.

bov sounds normal and it is venting to atmosphere. i can hear it sucking some air at low vacuum/partial throttle levels so im putting some K&N filters on it this week as soon as they get in at autozone.

believe me i checked everything i could without having to take off the UIM. hopefully we dont encounter any problems with the hose job. i have this sneaking suspicion its just a couple check valves that went out though. couple of those i have to take off the UIM to get to anyways. the ones i could find i checked and they blew through ok.

Nic