Hi, i have just replaced the turbo on my sons 1994 surf 3.0 diesel.The original turbo broke off a blade on the turbine . After replacing the turbo (not the nicest job to do) it has started surging under a bit of load, feel like its starving for fuel, so replaced the fuel filter,still the same. If the turbo over boosts dose it cut the fuel? Any ideas. Thanks in advance.
harrym7,
Jun 13, 8:30am
Yes to fuel cut, if boost goes over 14psi computer will cut fuel so check wastegate is working on turbo and make sure actuator line is hooked up.
snoopy221,
Jun 13, 9:34am
Cancel the previous PETROL info. Top of the injector pump has a boost compensating fuel enrichment device-ensure the line from it to the manifold is not blocked by remnants of dead turbo blade preventing boost pressure from entering the boost fuel enrichment device on the top of the injector pump.
tweake,
Jun 13, 10:10am
no boost compensator on those, they are diesel efi.
common cause of surging is the TPS. check you have the throttle cable connected correctly. hopefully you never removed the TPS itself. there is a setup procedure for them around somewhere.
otherwise over boost is common problem. check what boost level its getting. is the turbo original or Chinese aftermarket? if its got adjustable waste gate check that is correctly set.
the other thing was it turbine blade that snapped or compressor? if compressor it may have done piston damage.
xr6turbo2,
Jun 13, 9:15pm
don't believe it can be remains of turbine blade in the inlet manifold, i'm sure the blade will be in the exhaust system. compression test is no1 550 no2 is 490 no3 is 440 no4 is 420 I'm thinking the waste gate is not operating
intrade,
Jun 13, 9:52pm
well if the compresor side got nuked i hope xou also cleard the oil supply path to the charger and figured out wha the turbo blew up intercooler and all should be clened and flushhed and intake and egr serviced at the same time while looking for turbo debrey god knows how to spell that name lol
intrade,
Jun 13, 10:05pm
once this has been done correct and the fault that nuked the first charger found and fixed , then you move on what causes surge on a diesel not much. Air leaks in to diesel fuel system can make older diesel surge vaccume leek can also do it when the leek affects the airconditioning vaccume control. EGR dont make it surge as egr is on anyhow all the time at idle and part load . most easy is to fit a clear return and look for air in fuel and if it seems to have air you run it on a tank of diesel with short lines to rule any leaks from tank to pump out and look again for air. if still air probbaly failing gaskets on injector pump somwhere sucking air in. this is how its done and then you move on when you ruled one by 1 out to be the problem till you found the problem. if all is well mechanic vaccume and fuel then you have to Bring out the expensive tools and start mesuring with the scope what pump timing crank angle and injector pump tcv- timing control valve are doing. also the rest of it, it starts to become to complicated to tell you what to do on a forum as you need to know engine managment and how it all functions togather to mesure things and find whats going on.
intrade,
Jun 13, 10:13pm
you could see if it flashes any codes , if you cant figure it out dont clear codes before they have been recorded , some maybe your doing of unpluged sensor you might have caused or not.
intrade,
Jun 13, 10:19pm
most common fault for air is the pump membrane rubber on the primer pump on diesel filter, if you did not use a Diesel additive like winns edt chemtech or morreys diesel stop smoke in most of your diesel fuel in the tank with the diesel then that would be my first suspect for a surge problem. Seals shring no matter what but the old high sulfure used to swell the seals up so diesel never did let air in the pumps it also was super efficient in lubricating components . Sulfur was then more and more removed so this swelling and superlube was less and less, it is why you add a additive to slow down seal shrinkage and add extra lube back, i got noumerous threads should bump them again they are called Ulsd problem ulsd=ultra-low-sulfur-diesel.
frytime,
Jun 13, 10:29pm
Manuel or auto? Manuel have power limiter for 1st gear which can cause surge if switch is toast.
intrade,
Jun 13, 10:30pm
waste gate you can use plyers and move the gate , you should also see the rod move when its warm and you look at the rod you rev it full up and then the rod must move , they often stick when the turbo is not used for long , you cn test them correctly with a pressure gague and a bike pump to see when the gate opens at what pressure sould be just befr 2 bar. or 1 bar if your gague reads 0 when not connected as we live in about 1 bar pressure on this planet. something important to realise for diagnosing things.
so quiz question what is the boost pressure of a non turbo engine?
Also i dont know what your compression readings mean they look even you want the spec of what new engine comp is and i have no interst to waste time to do your job also so you should post that info not have us do that also for you . number 4 is the lowest but what is spec. all it tells us its not a bent valve for that .
tweake,
Jun 13, 11:20pm
just a bit rare for them to break the turbine thats all.
i assume the glows where all intact when you removed them. they are known to break off the tips of the glows which could do turbo damage if it got past the valves.
snoopy221,
Jun 13, 11:31pm
1994 1KZ aye mmkay. One thing you don't specify is rpm and load when surging or if surge has only developed since turbo replaced and boost requiring extra fuel to combust with extra air for stochiometric mixture. Could even be a dirty pickup filter in tank.
snoopy221,
Jun 13, 11:37pm
Incidentally seen more intake compressor wheels drop blades than exhaust turbine wheels
harrym7,
Jun 14, 7:11am
One should check one's facts before one speaks.
xr6turbo2,
Jun 18, 11:32am
Thanks to Harrym7 , post number 2, Your diagnosis is correct, the turbo is over boosting and tripping out the computer. I carried out some pressure tests,its exceeding 14 psi.So i will remove the turbo and get wast gate actuator set up correctly . Cheers
Since the public registrations are closed, you must have an invite from a current member to be able to register and post in this thread.
Have an account? Login here.