Turbo Not boosting fully

[stiusa]

I got my car back from the shop after installing 4 new fuel injectors made by Delphi (then called Rochester) that were suppose to be oem. Took the car for a spirited test drive, and the turbo will only boost half way. The needle on the boost gauge will always stop at 0.5 bar and cannot go any higher. I am wondering if the new injectors have something to do with it causing the computer to not function properly. The car still drives great and smooth, and you can still feel the boost, but not the snap back full boost. I am also wondering if there could be some wire that the mechanic unknowingly unplugged or not plugged in right. The car was misfiring, so they check the spark plugs and also follow the ignition wires to under the expansion tank. It was later determined that the fuel injector in one of my cylinder was clogged due to the car being stored, so I had all four injectors replaced. Already had the exhaust system inspected to make sure it wan't a bad cat. My car only has 16k miles on it, and is still like new. Any suggestion on where to look would be greatly appreciated.

[Rice crispy]

If it feels like it's not boosting properly check for air leaks on the intake pipe from the inner wing to intake manifold and do the wastegate wiggle (have a search for it on here). If it does perform correctly the check the earth connection on the inner wing on the drivers side in the UK as that will give false readings.

[J46_MAV]

I thought that 0.5bar (halfway on the boost gauge) was the designed maximum boost. Mine is standard and has never gone above this. If you have a chip I think it goes above this but otherwise 0.5 bar is correct.

[theelanman]

IIRC 0.6 is where is should boost to as stock.....
with a chip this goes to 0.95 at the top.......

[dapinky]

IIRC 0.6 is where is should boost to as stock.....
with a chip this goes to 0.95 at the top.......

Nearly right, G..... but close enough

But the main point being that the dash gauge isn't really that accurate, and should be treated more as a 'guide' to the boost level, rather than the actual pressure achieved.

The only way to properly tell the developed boost level is logging a run with elanscan, but in the meantime, I'd accept that the boost is there (to some extent), and enjoy the ride!

[lotusflasherman]

Manual says 'Maximum 0.65 bar'

Mines been playing up too. Sometimes only gives me 0.3 for a while and then goes back towards 0.65, particularly when I'm about to investigate it
Thermostat seems to be running engine bit cool so have a new one but warmed engine to rad fans kicking in and it was still 0.3 on a test drive.
Wastegate was overhauled recently but I have a Bailey Recirculating Dump Valve on it and am wondering if that's playing up..

Any suggestions?

P.S ... I've run with Elanscan on and it confirms the boost figures but can't see any other data that will tell me why..

Roadspeed 49mph, Gear 3, RPM 3925, Throttle 100%, Boost 0.28897 then
50, 3, 3975,100%, 0.30459
51, 3, 4025, 90.59%, 0.3124
52, 3, 4100, 81.96%, 0.3124

Coolant temp was 87.5°C.

[Elanlover]

.............Any suggestions?

Other than checking for leaks make sure the throttle cable is tight. Your foot me be down full on the gas but if the cable's not tight you won't get full throttle and full boost.

[lotusflasherman]

.............Any suggestions?

Other than checking for leaks make sure the throttle cable is tight. Your foot me be down full on the gas but if the cable's not tight you won't get full throttle and full boost.

Thanks but Elanscan shows throttle at 100% which I believe is reading the throttle position sensor so not dependent on cable tightness.

Turbo Boost Control Solenoid Valve was something else I considered but if that's not active the wastegate capsule controls boost to 0.41 bar.
Manual tells me that above 2,900 rpm the valve starts pulsing to allow the boost to go higher before the wategate opens, but if the valve has failed I should at least get 0.41 not be down at 0.3..

Elanscan shows mine got to 3150 rpm with Boost still at 0 and Wastegate Duty Cycle' at 0 but throttle was only 37.65% and I don't know how the ECU interprets those variables.
At 3175 rpm and 42% throttle, boost is starting to move (0.03) and Wastegate Duty cycle is about 20%.

If problem was there permanently I'd be checking the wastegate capsule for opening pressure but it comes and goes so the Bailey RDV remains my No 1 suspect.
I have another Bailey RDV on an Elan on SORN so might try swapping to see if that eliminates it.

[Simon_P]

that were suppose to be oem

What markings are on the injector body? How many Ohms resistance between the injector terminals?

[stiusa]

Thanks for all the replies. I have a manual boost controller installed, and the car was boosting at around 0.9 bar. Now, the boost will only stay at 0.5 bar no matter how much I adjust the manual boost controller.

[stiusa]

that were suppose to be oem

What markings are on the injector body? How many Ohms resistance between the injector terminals?

The injectors are already on the car, but I don't recall seeing any markings on the injectors. The injectors are the updated versions with 6 smaller spray holes instead of the single large one. I don't know if changing fuel injectors can affect how the computer controls the boost. Despite having a boost controller, the boost will not go higher than 0.5 bars (previously 0.9 bars). The car does idle and drive very smooth. I got the injectors on ebay.
http://www.ebay.com/itm/191637275013?_t ... EBIDX%3AIT

As for the Ohms resistance, I really don't have a clue.

[Giniw]

Well, have you checked your MBC?

[stiusa]

Well, have you checked your MBC?

Yes. It was the first thing I checked. Even tried driving it with the hose removed from the wastegate with the same result. It was boosting fine before I took it in to the shop to have the new fuel injectors installed.

[chrisP]

Are the injectors seated properly - is there any chance boost could be leaking past them?

[stiusa]

I finally found the problem. My HKS blow off vavle seem to have a small leak. I turned the bolt down to tighten the spring and it stopped the leak. The turbo now spools up to my set 0.9 bar and the car flies down the road. I am a Happy man once again!

[lotusflasherman]

Found my problem now.
I was out today in my SE and thought I was in a low compression NA. Boost has been coming and going and very inconsistent but no boost at all today so decided to investigate this evening.
I had a seized wastegate actuator rod pivot pin giving me overboost in April but got that sorted by cleaning the rust off the pin and putting it back with a new C clip and it worked great for a while.

Tonight when I removed the heat shields I could see my new C clip was missing and the rod had come out so the wastegate was free to flap around. After a lot of contorting I managed to get the rod back in and a new C clip in place but thought I'd operate the wastegate actuator many times to check this C clip wasn't going to fail.

Now pay attention folks - this may be better than the grab the actuator rod with pliers technique....

I removed the short section of hose and connected an electric footpump via a bit of polythene tube to the actuator and flicked the switch on and off for 2 or 3 minutes to open and close the wastegate for about 100 operations...
C clip is still there so I'll refit the heat shields tomorrow after a test run.

[HJ2]

electric footpump

[lotusflasherman]

electric footpump

Sorry, bad terminology, showing my age ... electric TYRE pump... still say 'hoover the carpet' even though it's been a Dyson for decades ...

[lotusflasherman]

Still not found my problem... the rod off was the 'no boost at all' problem but I'm now back to 'not boosting fully'..

Wastegate rod reconnected and first run seemed to give me much better boost but then it went back to the 'not a lot' condition ...

Connected laptop with Elanscan logging over a 2.5 mile run. First boost was about 0.38 and then all further readings maxed out between 0.3 and 0.35 even though revs were 5,500 / 6,000 at times on full throttle.

EMK2 Page 18-19 tells me the wastegate capsule spring controls the boost pressure to 0.41 bar when the Boost Control Solenoid Valve is closed (de-energised) so wondering why I'm not getting at least 0.41.

Has anybody had a wastegate flap valve burn out like old exhaust valves used to ???

I note that my graph of (inadequate) Boost sits within the graph of Wastegate duty cycle... are you there Geoff? Where is the 'Wastegate duty cycle' data collected from?

[HJ2]

Perhaps the turbine is stuck on stickey goo from a tiny tiny oil leak that accumulated over time.
Well, Mine was and had the same symptoms...