Trouble shooting some problems

Gravy · 09-30-2008

Long story short, i was driving from one store to another the other day and pulled along side a green 3000gt, driving a stealth myself i decided to rev a little and let off to get the bov going. Well, i do this and POP goes the intake pipe. I pull over on university right before i merges into 10, and fix the problem. I start driving to work, and it's clear i have a boost leak. Running a 3" gm MAF translator, SAFC-II but still stock turbos, despite what the bio says.

Anyways, i also found out, i blew out the throttle body gasket and one hose on the back side of the throttle body going to the brake booster. I fixed these problems tonight and fire it up. Runs at 1,400 rpm's with the BISS all the way down, and the TPS is set right, throttle plate is clossing 100% and sensor reads 0%. IAC motor has been giving me a code since i got it, but it's just now starting to surge on me like the DSM did at one point. Next step is a leak down test, but i have to get a few parts to build one... anyone else think of what the problem could be? Revs the way it should now and idles very smooth, but just too high.

P.S. EGR and emissions system removed from the car.

311evo · 09-30-2008

did you do a boost leak test? maybe something with the intake manifold gasket?

**asshanson** · 09-30-2008

Idle motor finally went out or is stuck open? Can you log the ISC position on a 3/S?

Gravy · 09-30-2008

I"ll have to check up on the logger if i can, havn't had it hooked up for a while, been just running it safe and rich for a bit. I'll see if i can hook it up and find out.

Boost leak test will be done in a couple days, ahve to get the parts for it, think i lent the parts to a friend, i'll have to ask tonight.

Febo · 09-30-2008

I dont have your boost leak tester parts Josh.

Also my vote is on the IAC. Think of the FIAV that we pulled off my TB. If the ISC motor was removed from there it would do the same thing. Your IAC just finally died and is stuck in the give it a shit ton of air mode.

Gravy · 09-30-2008

Well, good news/bad news now. I ran around on 3sx and found a nice IAC reset and followed that. Little different than the DSM, but fixed it. Car now idles between 800 and 900 rpm's with a SMALL surge in it, but i'm not worried on that.

AFR is still being a bit screwy on me, and it miss fires if i run anything richer than 13:1 under WOT. Also goes though a weird phase like it was before all these problems occured, where i get the car cruising at 55mph and it runs around 15:1 and drives just fine. After about 61 seconds, like clockwork, it goes from 15:1 down to about 11:1 or 10:1. Going to put the logger on it later tomorrow and see what the problem is, and if it's showing up there. If not.... back to the drawing boards. Before when i tried pulling the code, it just told me the O2 sensor was bad when the check engine light came on.

Febo · 09-30-2008

Or it could still be your IAC sputtering. Like your cruising fine then it decides to eat a s### sandwich and lets less air pass before regulating itself

Gravy · 10-07-2008

Or my fuel pump was going bad and wasn't supplying the right amount of fuel all the time. Why it was such a timed delay on droping from what i had it set at, and what it was running after a minute... who knows. Time for a new pump.

niterydr · 10-08-2008

Quote:

Originally Posted by Gravy

Well, good news/bad news now. I ran around on 3sx and found a nice IAC reset and followed that. Little different than the DSM, but fixed it. Car now idles between 800 and 900 rpm's with a SMALL surge in it, but i'm not worried on that.

AFR is still being a bit screwy on me, and it miss fires if i run anything richer than 13:1 under WOT. Also goes though a weird phase like it was before all these problems occured, where i get the car cruising at 55mph and it runs around 15:1 and drives just fine. After about 61 seconds, like clockwork, it goes from 15:1 down to about 11:1 or 10:1. Going to put the logger on it later tomorrow and see what the problem is, and if it's showing up there. If not.... back to the drawing boards. Before when i tried pulling the code, it just told me the O2 sensor was bad when the check engine light came on.

How old are your coils and ignition transistor?

Having the car go rich would indicate a loss of spark or surplus of fuel all of a sudden.

Gravy · 10-09-2008

Does it both cruising down the road or at idle, my 02 voltage(factory) doesn't change at all, and i figure from going 10:1 to as high as 16:1 would have to put out a check engine light while sitting still. But only does it durring driving conditions.

After running around on 3si, and talking to a few people, i seem to get a little bit too much knock under throttle and a count or two under idle. Going to replace knock sensor and drop down to 450cc injectors in the months to come.

Gravy · 10-14-2008

Now last night after idling the car.... i'm getting 20 some counts of knock at idle..... Sherlock, i think i'm onto something.

Anyone know what our max knock count on our cars SHOULD get to? I though i saw a rather high spike. But want to figure out first.

Gravy

P.S. Sorry for double post, new info, new question.

**Shane@DBPerformance** · 10-14-2008

Max on the 1Gs was 43, but you want to see 0.

Kevin 1G Drummer · 10-14-2008

How are you getting knock at idle? What's your base timing set at?

MustGoFaster · 10-15-2008

Quote:

Originally Posted by Kevin_1G_Drummer

How are you getting knock at idle? What's your base timing set at?

Good question, 91/92 3S's have adjustable CAS sesors like DSM's. 93+ are fixed like 2G's.

**Shane@DBPerformance** · 10-15-2008

I don't think there is nearly enough load at idle to get real knock/detonation.

Gravy · 10-16-2008

Knock sensor has a black "Goo" coming out of it, and with the car not running, key in ignition i get 0 counts of knock. After i start it, it runs around 20 unless i give it gas. Knock sensor seems to be bad, timing was fine last i checked, but unable to get logger to work atm.

The problem seems to be common after reading around on 3SI and the symptoms. Timing is the same as when i got it, and it idles like a champ(after re-setting the IAC).

450cc injectors were an option.... but i'm not 100% sure what i'm going to at this time.

96GST16g · 06-26-2009

u guys seem to know alot i have a 96 GST and i have to hold the throttle to a certain point to start and then if i hold it down to a certain point it will idle all screwed up like bob in the rpms and when i go down the road it like studders but under load its fine got ne ideas? i think tps may be im wrong no codes are thrown when obdii

**goodhart** · 06-26-2009

1. learn how to type and spell correctly
2. make an intro thread
3. make your own thread for this particular problem, it will help everybody help you.
4. don't bring up old posts 9 month old posts anymore

All of these things will give you a much more positive mitsustyle experience!

96GST16g · 06-26-2009

do u have any ideas sorry im new n tryin to find some one that isnt an asshole about tryin to help out

Gravy · 06-26-2009

Replied to your pm, can continue the convo on there. :-D