Hello all. First I have searched. I have looked at lots of forums. Just need a definitive answer on 2.5 questions I have. Background: I own a stock everything ( except for fluffy dice ) 300zx TT 2+0. Had an error code 34. I then reset the ecu, cleaned the contacts, retensioned the connectors and reconnected.Tested the ohm resistance of both sides of the connector. Restarted the car and have driven the car 4 individual times to check. Code 55 every restart. Stuck in safety boost. Fixes/problems/solutions : 1. Wastegates can apparently stick open after being put into safety boost. To be honest I am not sure what this would " feel " like or sound like. 2. Safety boost solenoids are fubar'd. 3. Boost leak ( one of the questions ). 4. Ecu problem? Questions : 1. Can a S1 Ptu have an affect on a code34 or initiate safety boost? I have an s2 ptu waiting to be put in but havent got around to doing it. 2. Boost leak testers. Are there good ones bad ones or should I just get the one that is on cazracing? This would also be a good time to get an intake right ? Thanks for reading and any help on other possible problems would be greatly appreciated. Oh and :zlove: I mean that
How do you know its in safety boost? Code 55 no faults Code 34 det sensor will put it in safety boost.
First a simple one, how long were you running it for after fixing the det code and is your temp gauge working? The car will also run on saftey boost until it's up to temp. The other option although less likely for a stocker is that the car is actually detonating, what RON (octane) fuel are you using? detonation in a stock car means excessive heat in the block, poorly set timing (bad job of 100k service) or you have a fuel delivery problem (worn out pump, blocked/damaged injectors) causing lean mixture
Remember too that the stock gauge does not read in PSI. The PSI value is roughly double what the gauge displays, although it's not an accurate gauge to start with.
Warren300 : long story short. Blast up to shops all good. Blast back from shops stock gauge ( haven't got around to putting in a proper gauge ) will not go past the zero point on the gauge. Also can't overtake a Mazda 121. Checked the codes. Code 34. Took the negative off the battery for 8hours to reset the ecu. Then the 4 starts and restarts with code 55 blinking away on the ecu LEDs each time. So now I am stuck in little to no boost mode. I thought that if it was detonation then it would for a short time at least reset the safety boost at ign off then start again so even for a short time I would see proper boost. Fists: the 4 drives were for around 15 minutes each. Still have stock gauges for the water temp... Yeh I know about how bad they are but it does not move off from halfway at all even in this hot weather. Bp ultimate always. The previous owner ran 95 all the time but have to assume that the ecu has noticed the change? going to check the temp sensor now. Pexzed : you're not wrong!! Heck can't even work out what it is reading in! Basically the car when bought was... Awesome :zlove: it was pushing back and the stock gauge used to go all over to the right. But after this blast to the shops it is way lower. Got a consult cable coming so I might be able to tell you more about some of the other bits and bobs. Going to research on how to test for detonation without using the detonation sensor ... Hahah.
When you tested the resistance on the det sensor sub harness (goes behind the engine to the detonation sensor, not the ecu), what did the reading give? It should be 1000k ohm, or close enough. I had a similar problem a while ago, where the car would be in safety mode, but show code 55 (no errors). It started one morning while I was on my way to work. When I tested the resistance on the det sensor sub harness, I was only getting around 600k ohm. I believe this caused the ecu to think the engine was detonating when it really wasn't, so put it in safety mode. I used a resistor to temporarily bypass the det sensor: no longer in safety mode.
Ok so I got 0.550 so going to back up a little and see if the bypass works then a relocation. Fingers crossed it is purely a troublesome det sensor. I thought one side had to be 0.500 ohms and the other side was 1 k ? More tech article reading methinks.
There wont be any relocation. A resistor costs nothing and mine's been bypassed for what must be three years. I've read numerous respected people say relocating it is a waste of time and or doesn't work.
Safety boost does not limit it to zero, only wastegate pressure of about 6-7psi. There is likely something wrong with your wastegate actuators if that is the problem you are having. Get rid of the code 34 error, and then keep diggin.
Not getting code 34 any more. Thanks for the direction to the wastegate. No doubt they will be in the most hardest place to get to and I will need hands of a small child to get in there. Searching right now on how to get to them.
Changing actuators is pretty much a engine out job. The drivers side is practically impossible as it runs between the turbo and the head. Chuck on a proper boost gauge first, if you are actually getting 0psi then there is something quite wrong. Have you checked for boost leaks yet? Does it idle ok?
Putting in a boost gauge today and ordering a tester from caz. I seriously hope it is a leak but the way the stock gauge always, without fail, moves to the same position on the stock gauge and never fluctuates is pointing me to your original idea of a wastegate problem. Logic would dictate that if it is stuck open/closed at the same position then I would presume the point on the gauge would always be in the sam position. Further to this leaking boost problems would have the gauge needle hunting around? Never owned a modern car before ( 15 cars owned never younger than 1977 ) so a wee bit out of my depth here.
The wastegates could be stuck completely open. I'm not sure if this would completely stop it building boost. The port that the wastegate flap covers is quite small. A boost leak wouldn't make the boost gauge hunt around.
you may have a seized turbo i had exact same symtoms, mine said it would boost to about 1 psi (tranfer across the balance pipe). how to test this without you pulling it all appart is, (1) get a friend to help, (2) loosen off you intake pipes going to plenum (loose enough so they can be removed easily some wd40 will help alot) they should slide back and forward, (3) while the engine is running at 3000 to 3500 rpm ( have friend hold the revs stable) rip one side of the pipe off you should feel a blast of air jetting at you coming from intercooler side the engine bay this may also stall your car dont worry just need it long enough so you can see if lots of air is blasting out repeat until your sure theres air going to your plenum. (4) repeat same steps on the other side of car and report back with findings
got under the car and managed to move the actuators on both sides ( oh yes if I need to change these I'll need to lift the engine out ! ). I think mechanically they can move back and forth. Wired in a 1 megohm wire to make sure it wasnt a det sensor. No change. Boost gauge installed and it is showing exactly 0 psi like the stock gauges. Found a sheared off vacuum line replaced this . no change. boost leak tester ordered. Pauly: Will try this. Assuming that this is ok then logic dictates that air is getting to the turbo. then the turbo might be seized ?
Here we go... You moved the actuators but where they pulling the gate shut? sure the actuator moves but to what degree? if you aren't making any boost either one of two things are happening its either being chucked out by the wastegates being stuck open meaning the actuator isn't closing it fully, or you aren't making boost to begin with. Its not likely a boost leak from anywhere else because the zed would stall. This is a big leak to be making 1psi, which is in fact impossible because the wastegates open themselves at about 6psi. In conclusion your turbo/turbos are rooted or the wastegates a buggered. A good way to test this is with an electronic boost controller or a $20 turbo tech manual controller off ebay. Either of these controllers will for the most part take the stock wastegate pressure out of the equation. The actuators wouldn't see any pressure until whatever you set the controllers to.
Or just disconnect the actuator boost lines and plug them? Take care though as the plugs will need to hold any boost that does develop and if you are spooling and producing boost you could easily over boost your engine if you accelerate enthusiastically
Still waiting for all the testing bits to arrive. But I have put mclovin's stuff into my things to try next. Got to do some research into MBC's ( will eventually want a ebc but for now.. ). I read some forum "discussion" on whether you need to unhook the safety boost solenoids or not. More confused than ever. I'd like to try the easiest things first. so boost leak hunting seems to be the easiest thing than trying fists idea to get to the wastegate boost lines as I have big hands. If mclovin is right ( and I hope he isnt for my wallets sake !! ) then it is engine out time. Which the anarchist part of me wants so I can build an engine my way. But am I doing any damage ( other than to my pride ) running with absolutley no boost whatsoever ? I hasten to add that there is nothing out of the ordinary coming out of the exhausts. Still getting code 55. I test every day 4 or so hours.:rofl:
