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Forum nameTurbo/Nitrous Tech
Topic subjectTurbo woes
Topic URLhttps://forums.2gnt.com/dcboard.php?az=show_topic&forum=i8&topic_id=100963
100963, Turbo woes
Posted by DSMTalon, Jul-26-07 06:30 PM
im in hell! i FINALLY installed and got everything sorted out for my engine/turbo and i cant get the stupid thing to idle, its hard to start without working the pedal some and there is next to no throttle response. i have my static fuel pressure set at 55psi and fuel pressure with a vacuum is erratic. it doesnt stay consistent. as far as EGT's go when the engine does run( and it runs pretty decent around 2500RPM then the EGT's sit right at 800, and they dont fluctuate. However im suspect of the SFMU unit, as when i pressurize the fuel rail to adjust the static, the fuel pressure drops right away when the fuel pump shuts off and there isnt a fuel leak. is it supposed to do that? ive checked the blue diaphragm that goes between the two halves and it isnt damaged or anything and i was missing a screw for the halves, but i replaced it today and there wasnt any change in it. but im assuming that my car should idle pretty close to stock, seeing as how the FP isnt much different from stock, and the injectors are stock. so where is my issue?

so heres the low down on my setup:

JE psitons/eagle rods/yada yada on the lower end, upper end has a 3 way valve job, crower stage 2 turbo cams, crower valve springs and that about sums up any major changes to the engine. ive installed a treadstone kit on the engine and ive got the wastegate set to 7 psi, and im running the stock injectors on a -6AN fuel system with a SFMU unit for control. since i used one of terry's fuel rails i used a jegs fuel gauge and tapped it into the line off the fuel rail going to the SFMU so i would know where my fuel pressure is. in the SFMU i have the 3.62 disk and im not sure what spring...i only have one spring for my unit. as far as engine vitals go i have an autometer Boost/vac gauge, narroband A/F ratio and pyrometer.

odd thought: the IAC solenoid had been disassembled at one point for a Jeep TB that i had decided i would reinstall at a later point..could a pintle that isnt adjusted to the correct legnth cause my car to not idle?

ANY HELP AT ALL WOULD BE GREATLY APPRECIATED!!!
100971, RE: Turbo woes
Posted by DarkOne, Jul-27-07 06:49 AM
Originally posted by DSMTalon
but im assuming that my car should idle pretty close to stock, seeing as how the FP isnt much different from stock, and the injectors are stock. so where is my issue?


This in itself isn't wrong, but...

Originally posted by DSMTalon
crower stage 2 turbo cams


...making the assumption that you're going to idle at all like stock with a fairly aggressive cam is just asinine. Your idle sucks because you're running an aggressive cam. Aggressive cams cause low vacuum. Low vacuum means you're going to run richer. Reduce your idle fuel pressure and get used to idling like you have aggressive cams.
100976, RE: Turbo woes
Posted by DSMTalon, Jul-27-07 08:34 AM
lol ok i did stick my foot in my mouth with that one. i cant expect it to idle like stock, but i cant seem to get it to idle below 1500RPM (with my foot on the pedal, as the IAC doesnt seem to be working)and i would think it should idle a bit lower than that..roughly 1000RPM maybe? ill try lowering my fuel pressure later today and see what that does for me. also im wondering since the engine is from a 97 and the vehicle is a 96 ive noticed that i had to swap a few sensors between the engines( crank, cam, IAT, CTS) im wondering if the cam sensor magnets are different between the years too, and i need to swap that cam sensor magnet for the 96 one to match the sensor?
100977, RE: Turbo woes
Posted by DarkOne, Jul-27-07 09:12 AM
Can sensor signal is consistent through all years. There is no difference in the sensor (harness connectors aside) nor the magnet.
100979, RE: Turbo woes
Posted by DSMTalon, Jul-27-07 02:12 PM
ahh then there must be a difference between the avenger/eclipse harnesses...cuz i did have to swap the sensors. oh well that point is moot. as far as the engine and its issues go, ive ordered a IAC solenoid for it and ill replace that on monday when it comes in. But ive still yet to find an answer as to why my engine is so boggy. it acts almost like the timing is jumping all over the place when you try to accelerate the engine. and like to say, it doesnt want to idle anywhere north of about 1.2k. theres been a few occasions where ive got it down to about 1k. id be fine with 1.2 if i knew id start and idle there consistently. currently i have a rubber hose that i split and used for a stopper on the throttle blade to keep it idling. (SAFC reads about 8.0% throttle) in this RPM range i have about 10in HG vacuum according to my gauge. ive turned down the fuel pressure to about 45psi on the gauge, but there seems to be little improvement in the engine performance. i have had a cel come on, with two codes showing up the first one being a P1296- no 5 volts to MAP sensor, and the other code was a P1698 relating to a TCM CCD Bus error. the latter code im not worried about as it deals with me running an ATX computer in a car that has a manual tranny swap done. but with the code 1296 is it possible the computer could be in limp mode and not control timing right? what can i do to correct this? thanks guys keep the help coming!
101005, RE: Turbo woes
Posted by DSMTalon, Jul-29-07 04:04 PM
ok heres an update on my plight: i know realize what i was getting at with the cams and the idle. it wasnt so much the lumpy idle i wasnt expecting, but i was expecting the car to idle somewhere...not just start and die as if the IAC was dead. the car wouldnt idle at all without working the gas pedal over. anyway now the car will idle sometimes, but it usually takes 10 tries or so before it will actually start and idle instead of dying. when it does idle, idles at 900RPM and this is some of the engine vitals ive noticed:
-8 vacuum reading on gauge, -517mm of vacuum on SAFC-II, MAP sensor voltage @ 2.4V
EGT: 900*F
Fuel Pressure is at 42psi w/ engine vacuum.

at this point im believing my problem is more timing related, as the temperature gauge does climb up rather quickly,and keeps on climbing up to dangerous levels. between this and the poor start and total lack of throttle response im wondering if my base timing is off. i have had the head milled a little, but when i put the belt the marks looked like they lined up great(i did use adjustable cam gears). this leads me to my next question: which way do i need to rotate the gears to retard the timing? is there a formula or a rule of thumb to calculate how much to retard the timing to compensate for milling?
101012, RE: Turbo woes
Posted by DarkOne, Jul-29-07 09:46 PM
You have a timing problem.
101032, RE: Turbo woes
Posted by DSMTalon, Aug-01-07 08:40 AM
ok i got the whole hard to start thing/no idle sorted out.it starts and idles pretty good now. i took it out for its maiden voyage earlier, and the thing doesnt run worth a damn. zero throttle response, its boggy, doesnt run worth a damn at anything above barely stepping on the throttle, it builds 0psi of boost, it just takes the gauge up to 0 and there is no positive pressure. if i didnt know any better id say it was fuel cut, but i do have an FCD.
101041, RE: Turbo woes
Posted by DSMTalon, Aug-01-07 06:46 PM
err update: found a bad connection to my FCD. fixed it and it runs pretty good...not as good as i thought it would. there's still gotta be something wrong. it doesnt build boost until like 5500RPM and even then its only like a few PSI. My wastegate is set at 7 psi. and im getting a "fluttery" sound from my BOV indicating im not seeing all the boost i should be. oh yeah...and it still overheats. does anybody have any reccomendations for bleeding air out of the system when the little bleeder is like corroded shut to the point of almost stripping out the hex thread in it?
101156, RE: Turbo woes
Posted by bzoss, Aug-09-07 11:04 AM
I had a problem with overheating just because the turbo sits so close to the radiator and it is really hot. I just but a shroud around my turbo and cleared that problem up.
Good luck with the tuning and getting her running right. I am still fighting that battle, over a year later!
101158, RE: Turbo woes
Posted by DSMTalon, Aug-09-07 06:38 PM
well as far as the cooling goes...im about ready to scream. ive installed a secondary fan where my a/c condenser fan was (a hayden unit) and wired it to come on with the radiator fan. then im running a bottle of water wetter in it and the thing still climbs up pretty high. it doesnt completely peg out...but it gets close...way too close. the temp does come down some with the heater on full blast...but thats no solution. but at an idle, it will actually cool down some. but the fans stay on all the time. so anyway everyone i know is telling me its because of the crower turbo cams. but this is also coming from people who run carbs and V-8's. i dunno if there is any truth in this. but at this point, its come down to me putting back in the stock cams. so im gonna do that tomorrow evenging. ive also ordered a 160* thermostat and a turbo wrap kit to help keep heat down in the engine bay in an effort to get the thing from overheating. if this doesnt work then im pretty much screw'd me thinks.
101163, RE: Turbo woes
Posted by bzoss, Aug-10-07 07:45 AM
read my last post...

wrap your turbo in a heat shield of some kind
101170, RE: Turbo woes
Posted by DSMTalon, Aug-10-07 09:06 PM
lol i did. i was just affirming my planned course of action :thumbsup
101221, RE: Turbo woes
Posted by 2GeclipseRS, Aug-15-07 10:49 AM
What kind of fans are you running as your primaries?

Upping your thermostat is a great course of action.

How'd you sheild the hot-side of your turbo? Cooking pot?
101223, RE: Turbo woes
Posted by bigrob3232, Aug-15-07 01:26 PM
Originally posted by DSMTalon
err update: found a bad connection to my FCD. fixed it and it runs pretty good...not as good as i thought it would. there's still gotta be something wrong. it doesnt build boost until like 5500RPM and even then its only like a few PSI. My wastegate is set at 7 psi. and im getting a "fluttery" sound from my BOV indicating im not seeing all the boost i should be. oh yeah...and it still overheats. does anybody have any reccomendations for bleeding air out of the system when the little bleeder is like corroded shut to the point of almost stripping out the hex thread in it?


The fluttery sound you are hearing is turbo surge and that usually mean the bov isnt working...due to either the bov itself or the vaccum going to the bov... I'm not sure on the over heating though
101228, RE: Turbo woes
Posted by DSMTalon, Aug-15-07 06:59 PM
ok well i guess its been a bit since ive updated this.. i fixed the overheating issue..come to find out the stupid radiator that i thought was good and had around 1k miles on it had a few (metaphorically speaking) tampons in it. so i dropped in a new radiator and viola! no more overheating, but i am currently running it without a thermostat. when my 160* shows up ill drop that in. currently i have no heat shield on the turbo, but while i ordered that t-stat, i also ordered a turbo heat shield kit from howell. so when that shows up ill wrap up the exhaust housing and down pipe. as far as the fans go, im running a hayden fan on the passenger side and the driver side has the stock a/c condenser fan on it, since its slimmer than the original fan on that side. eventually ill replace it with another hayden unit, since theyre cheap enough. I still am experiencing the BOV flutter...ill check into the vacuum signal for that bad boy..i just tapped the signal right off the port on the TB. maybe that was a bad choice? ill try running it to one of the ports on the back of the manifold and see what i get.

Edit: thanks for the help guys i never would have been able to do this without the info on this site.