Having some teething troubles now that the engine is back in. I don't appear to be getting much (if any) boost and the boost gauge only just gets to the negative side of zero with some revs on. Engine appears slow to rev out to max rpm and has not much pulling power on the road (2nd gear (auto) had trouble getting past 5,000rpm on a slight incline). Don't appear to have cold start/fast idle working on cold engine. When warmed up the idle screw is a long way out to maintain 700rpm. Guess I better start with what has changed during the rebuild: New CHRAs on stock turbos New stock valves (HTC coated) Manifolds and turbo housings cleaned and HTC coated Bores honed and new rings Bigger SMICs 740cc injectors Nistune board running 48P76 base program Using a straight 30 weight oil for running in Adjustments/Checks made: Nistune auto correct for bigger injectors Base timing set at 15 degrees TPS set at 0.44 Conzult shows code 55 (might have been happier if it showed some faults) Most of the pipes and hoses had their ends taped (rather than rags stuffed in) during the rebuild, so fairly confident that I haven't sucked one in anywhere. Can't get my head into gear as to what to check next or best process of elimination. Was sort of hoping that the run down the road at full throttle would blow out the cobwebs and all would be good. No luck there. Looking for the solution from the wise men out there.
No, will check tomorrow that they are staying closed. Didn't think there was any adjustment to the stock wastegate actuators.
lol/ PITA time ,, who did the rebuild on the turbos . no not closed flap, closed flap = full boost open - less boost .. when they put the turbo back together they may not have set it up properly .. your actuator ( stock ) is not adjustable but if you turn the cold side a little on the turbo it will do what you are saying your car is doing ..
Got Eric to assemble the turbos for me, and he did say I might need to slightly rotate the housings for correct fitment. I did test them before fitting to the engine, BUT I did have to move them slightly when I installed the pipework and didn't think to retest them after that. If this is the problem, I hope its not the driver's side. Thanks for the info.
well i think i got it in one . PITA TO FIX and you cant really tell, if the driver one is out you will not know because as you know you just cant get to it ( you can but very hard ) drop the subframe frame and start again
Hey Dino have you tried it without the boost controller if it is your wastegates wouldn't make a difference... worth a try though.
No boost controller, just standard vac lines with boost jets. But I will check I haven't plumbed a vac line in arse about through the solenoid.
Shouldn't effect it. You need pressurized air to get the actuators to open. So even if you have them not hooked up you should get wastegate boost. I would think you would have to really have the turbo's clocked a lot for the standard actuators not to shut the gates to get at least 5psi. Maybe jammed wastegate arm? See if it is fouling on anything.
Not really a little bit will do it on stocks and yes They are closed when engine is of and open when running. What will fix it ( not 100% ) but to get you tuning is a boost controller cheap and nasty is good. Set to almost full boost and then you should get something. (. This is not an ideal thing to do but for a test all good )
Another quick thing you can do to test. Is clamp the accuator feed line and you should get full boost. ( don't gas it hard ) use a boost gauge to see level. Use 2nd gear gas it slowly. You will know and hear it starting to boost. ( do not thump it hard as you will be on full boost this is just to check if it will boost up )
Looks like I may have a problem with the wastegate actuator on the LH turbo. There is no spring pressure holding it closed. will have to do some dismantling. luckily I have a spare one I can throw on. Hopefully this is the cause of the lack of boost.
Actuator is working fine. Problem is in the wastegate arm and its position when closed. Have compared it to 3 other turbos which all have the link arm hanging almost vertical. On my LH turbo the link arm is angled about 30 degrees off vertical towards the actuator. This has the effect of making the actuator arm too long and holding the wastegate open all the time. (?? Was sure I checked this before I put the engine in? Maybe I checked the RH side twice?) I was going to drill another locating hole for the pin but decided instead to put an 'S' bend in the actuator arm to shorten it to the right length. This way I can still make small adjustments to it if necessary. Will be a few days before I get a chance to put it back together and test the engine for boost. Fingers crossed.
Finally got around to working on the zed again. So far have found at least one cause for the lack of boost - Don't know how, but i left a rag in the RH ducting that sucked itself down to the impeller! (And here was me confident that I didn't leave anything behind). Should have the engine out later this week and check if anything has been damaged.
I've heard of this happening before, and its really easy to do with a turbo vehicle! The one I heard it happen too was fine after removing the rag, so fingers crossed!
Yep, done that ... no damage to the turbos, but had to remove all the piping and intercoolers and clean as the turbos turned some of the rag/s into fluff which coated the inside of everything.
