Mk.1 UNO Turbo Ignition timing in X19

darbyx

Daily Driver
HELP PLEASE? - Red Hot Turbo after gentle 20km drive in my X19
New engine now blown head gasket after 900km of gentle running in.

BACKGROUND- Turbo was glowing red hot - have reduced this by correctly plumbing the turbo vac hose from the PLENUM to the Ignition ECU, not directly from the turbo (ie it now measures pressure from the other side of the butterfly valve). Then 24hrs later the head gasket blew = undrivably rough running and surge tank full of bubbles and foam.

TIMING PUZZLE
The distributor has only the rotor button in it.
THE MANUAL:- Says when fitting the distributor you are to set no.4 cylinder to TDC and then align the rotor button via a mark on the dizzy to no.4 terminal and tighten bolts THATS IT. It says it has nothing to do with adjusting ignition timing and that timing is handled by the ECU.

Crank Angle Sensor

THE MANUAL - Says that you align the crank angle sensor so its "built in" TDC pointer correctly aligns the crank marker at TDC. BUT elsewhere it specifies that the static engine timing must be checked - with turbo Vac hose disconnected - and is to be set at 8 - 12 deg BTDC at 900 RPM. BUT
It does not specify where the adjustment for this is to be found. However the crank angle sensor is held in place by two M6 bolts and the holes in the mounting plate are elongated - Surely for the purpose of adjustment.

NOW when I checked for TDC while assembling the engine I found that it was out by around 3mm, (I thoroughly marked its position before I moved it) . . . and that's 3mm anticlockwise . . .and the engine rotates the other way . . . i.e. it was 3mm BTDC.

By putting 2 & 2 together - - in the Factory they had moved the crank angle sensor so that it gave correct ignition timing, (8 - 12 deg BTDC at 900 RPM) and therefore only approximated TDC - hence I found it to be 3mm out.

Does anybody know if my conclusion above is correct? Is this the correct way to set the timing os is there some other adjuster in the Mk. Uno Turbo engine??
 
Sorry for your woes - I can empathize having gone through several head gaskets due to timing issues.

Can't help much with Uno - specific setup though. Your supposition based on the hardware seems accurate though.

My question would be whether you swapped over ALL the engine management from the Uno setup to the X1/9 - if not, the fuelling is highly unlikely to be appropriate for a motor that sees positive pressure. Without a wideband gauge to monitor AFR's, it is quite possible you are running insufficient fueling which would give the same end result as excessive timing. If all you have sufffered is a blown HG (and no ring/piston, bearing damage) you have been lucky thus far...

Can you outline all the changes you made for the turbo motor install for clarification?
 
Thanks.

I bought the whole Uno Turbo Engine, gearbox, wiring loom, and its 2 computers. The only thing in the running gear that is not original or new is the fuel pump. Before the head gasket blew, I took it to a dyno tuner and he confirmed that the boost was running at 7.5lbs and that the fuel mixture was OK - out to 5,000rpm - which was as far as we revved it. Unfortunately he failed to detect or correct ignition issues . .. oh and I installed the original oil cooler and a water to air intercooler using a modified quad bike radiator which seems to be doing fine
 
Hi Darby, sorry to hear of your blown gasket, these engines are usually very tough. The turbo and outlet elbow will glow red hot - it's normal, and unfortunately in the X1/9 tends to cook everything nearby!

You will have to set the basic timing by trial and error, tweaking the TDC sensor then running the engine and checking the timing with a strobe light. The most accurate measurement is given by the pip on the flywheel and marks on the bell housing window. However, first make sure all your vacuum connections are correct, as it's not clear from your original post. The Microplex ecu must get its vacuum from the plenum, nowhere else. The fuel pressure regulator must get its vacuum from the plenum, nowhere else. The dump/recirculating valve must get its vacuum from the plenum, nowhere else. The wastegate may have its vacuum taken from either just on the compressor outlet *or* from the plenum. The wastegate is the *only* component that may take its vacuum from "in front" of the butterfly. You can tee the other components together if necessary, but they must each be able to see manifold plenum vacuum.

Vacuum connection for fuel pressure regulator:


Vacuum connections for ecu and dump valve:


Wastegate actuator connection:
 
Thankyou Very Very much for replying. This is So Helpful.
There are VERY few of these in Australia, especially set up as road cars with standard Turbo and so anyone with experience is so hard to find!

1. wrt "Vacuum connections" My fuel regulator was always correctly connected to the plenum, I corrected the ECU to the plenum (along with fuel reg.) and noticed an immediate improvement in power, smoothness and quietness. However as it arrived (imported from NZ) the dump valve was plumbed directly via T piece to the waste gate. So I have had it connected that way. So I should change that unless . . . Mine is a Mk. 1, yours appears Mk.2 could they be different in this respect?
Uno.Eng in.3.JPG


2. Red hot Turbo.
Could you please give me more info on your experience of the turbo glowing red hot. AFTER I correctly plumbed the ECU I could scarcely see it glowing (in the evening light) after a short gentle 20km run at 100km/h (60mph) in 20 degree ambent. BEFORE I corrected it it was red hot from the same run in same conditions. Also how do you manage it - After switching off I hear the coolant boiling in the pipe as it 'hits' the 400 degree red hot turbo after switching off - so I run the engine a bit longer to cool it down.
RedHotTurbo.jpg


3.Engine Temp
. Even after getting the ECU plumbing correct the engine temp on a cool day hits 85-90 deg C (180-195F), even with new radiator, pipes, hoses, two fans and a 75 degree C (165F) thermostat. What temps do you see on yours? Any Advice?

4. Timing, OK so the only way to adjust static timing IS by moving the TDC sensor!! And you have to keep adjusting and checking with timing light YES!! My car is using the original 4 speed bellhousing and it will be hard to see timing marks with my water intercooler in the way . . . I have the original Uno Turbo fly wheel fitted (122 teeth!). . . .QUESTION I cannot understand how there can be marks on the flywheel to help with the timing. As I recall there re 6 bolts holding it and no 'key' to cause it to be fitted in only one of six possible positions?

Getting the engine in!

Uno.eng1.jpg
 
Nice car! The dump valve must be connected to the plenum to work properly. It may be teed to the wastegate *only* if the wastegate is connected to the plenum as well. Yes the car in my photos had a Mk2 engine, so there are minor differences in where the plenum take-offs are, but the vacuum connections I prescribed are correct for all turbo engines.

As I recall, the flywheel bolts have offset centres so you can only fit the flywheel two ways. So, if you don't pay attention you can get the timing pip 180 degrees out! There should be timing marks on the cam belt cover too.

Have a look on YouTube at engines on a dyno, both turbo and normally aspirated. Remember your turbo and exhaust is glowing like that in the cramped engine bay of the Fiat, so take care with wiring, hoses, alternator etc. as they will be grilled!

80 - 90 degrees is correct for the engine coolant under spirited driving. It may be a good idea to fit a more modern radiator, either a re-cored original (the original end tanks can be stretched to fit a three row core), a bespoke aluminium rad, or a VW Scirocco rad swap is a popular mod in the UK. There is little to be gained by two fans as they should not actually be needed above around 50 kph or so. Check your coolant pump impeller clearance to the pump housing, it is beneficial to keep the clearance on the tight side of spec to maximise pumping efficiency. The Montecarlo actually has a special coolant pump with a deeper impeller to get adequate flow through the long coolant circuit compared to Fiat/Lancia's front engine applications.

As long as the cap is not actually blowing off, it is normal after a run to hear the coolant boiling in the turbo and venting into the header tank, this is intentional and is a clever thermo-siphon trick Fiat have used to give after-run cooling for the turbo bearing housing as it suffers heat soak from the hot side after you switch off. Overheating the oil in the turbo bearings causes coke to form on their seals, resulting in premature failure. Other makers such as Audi and Mercedes have a small electric pump to do the same for after-run cooling of the turbo. This is also why people recommend a period of idling after a hard run to allow temperatures to come down. The Fiat thermo-siphon effect relies on having a short pipe run from the turbo coolant out connection to the top connection on the header tank, which must be at least 11mm ID. You can see this pipe in my photo, which shows an Uno Turbo header tank. The stainless X1/9 tanks have a big enough top pipe, the plastic versions do not.

One thing I have considered is to remove the rain tray from the engine lid and fit a modern low profile rad fan to blow air up through the lid slots. This would be controlled by the injector cooling fan switch so it could run on after a drive until engine bay temps come down a bit.
 
Thanks this is really helpful. How long have yo been running your X with an Uno Turbo?

Yes I have a tri-core radiator already installed. The second fan in my case is permanently on because half the front of the original radiator is 'covered' by the small water intercooler radiator. My new pump's clearance was such that I had to shave off bits so it wouldn't jam when bolted up with std gasket. Was aware of the thermo siphon trick, and initially didn't have it plumbed into the header tank - fixed it - but til now nobody could tell me red hot was normal in a road car - Local knowledge here thought it only happened on a Dyno under stress and yes all hoses etc are well away. The exhaust Manifold and the turbo have been ceramic coated.

I have installed two 120mm 150cu.ft/min Motor bike Rad fans as extraction fans. One in each side pod. The RHS one sucks air from the RH inlet through ducting to the oil cooler and out the RH louvres (series one body), the left hand one works through a 50mm pipe to suck air from between the turbo and the heat shield, sucks it out through the LH louvres
I'm currently seeing a max of 87 C in oil temp even with the ducting I made removed!
IMG_7037b.JPG


IMG_6808.jpg


I have no injector cooling fan or the ducting for it. Can you post a photo? Yes I have considered other fans for cooling as you suggest.

Blow off Valve?
Hmmm. I thought the point of the blow off valve was to release pressurised air when the throttle closed, preventing the pressurised air from 'hitting' and damaging the throttle valve itself, so that it had to be set to read pressure before the throttle body not after it?
 
Blow off or recirec valves are normally taping into post throttle (plenum) pressure, except variants that use a dual port to stabilize, like my old Greddy Type R. As far as I recall it's to protect the compressor wheel from 'surge' damage, not to protect the throttle plate, although that could be a secondary consideration...

Factory CBV/recircs would always use plenum pressure, not inlet pipe.

EDIT: Your air filter looks extremely small for a turbo application - did you use an air flow calculator to determine appropriate flow requirements - or just stick on whatever fit? Limited air flow will definitely create problems at higher rpm(!)
 
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With your ecu vacuum pipe connected in front of the butterfly you would have been running with retarded timing all the time. The only time it would have been near correct would have been at wide open throttle. Retarded timing will heat the exhaust up excessively, so that's probably why you noticed it. In general if you are just pottering about in traffic the exhaust will be black or maybe just a very dull red. Once you start driving with enthusiasm or have it on the track, things will get orange pretty quick.

You have certainly gone to town with cooling air management, no bad thing with the cramped conditions! Re injector cooling, I never implemented it. It would have fitted in much the same way as the original carb cooling arrangement. In my second photo you can see the cooling air inlet on the manifold just next to the dogbone and between the ICV hose and injector wiring.

Sadly I haven't had a turbo X for many years, the car in my avatar will be the next one. The car in the photos above I originally bought in about 2006 with the intention to rob its Eurosport bodykit. The car was rusty and wouldn't have passed another MOT without lots of welding. I ran it for the few months that it had a "valid" MOT and fitted the Mk 2 UT engine. I used the X1/9 gearbox and had fun and games shaving the inside of the bell housing to fit the UT clutch. I also used MegaSquirt, so had no afm. In the third photo you can see the air filter fed directly into the turbo.
 
LOL,
No you can't see it in those pics, it is buried under all the re-routed hoses and other clobber. It sits immediately above the clutch slave cylinder. A Picture is worth a thousand words.
Plumbing as Follows
(see pt. 1 below) - goes from a 45mm 90 degree expanding to 51 out of the turbo
(see pt. 2 below) - then to 45 degree expanding to 56mm into intercooler
The intercooler is a 300mm PWR barrel type - separate radiator and elec pump and pipes front mounted
(see pt. 3) - into a 90 degree reducing from 56mm back to 51mm
(see pt.4) - another 51mm 90 degree into the 500mm inlet pipe then 90 degree to throttle body(which you can see in the pictures above)
IMG_6909b.jpg


I see you have a Uno project. If interested I can send more pics, also of front radiator mounting etc
 
Still not clear to me.

For static timing:
Should the tdc markers on the sensor holder and the pully lining up at 0 degrees before tdc (bellhouse reading)?

Or at 8 degrees before tdc?

Will the microplex calculate the best timing based on a signal at 0 degrees or 8 degrees before tdc?
 
Not a great answer but I recall reading in the UT service manual the spec for ignition timing is 8* at idle. And the description of mounting the sensor sounded like it was installed at TDC (although I don't recall it saying anything about adjusting it). So I believe the static setting is at 0, and the ICU will set it from there (to 8*). In Rachael's earlier post (above) she said to set the sensor to give the correct reading on a timing light (i.e. engine running). That sounds to me like you set the sensor to yield the 8* at idle. I'd start at TDC static and see what the timing light reads at idle. Then you can move it if needed.
 
I agree with Jeff - in principle all crank sensor setups are based on a setting referencing true TDC. This chart is for Bosch systems used on Volvo's, however the basic positioning is always in relation to TDC. Volvo offers no means of adjustment.

So, set sensor tip based on TDC, then adjust sensor as needed after checking timing at idle.

X19_LH24_00001zb.jpg


Design & function - again has to be similar in principle to Fiat setup
X19_LH24_00019.jpg
 
Very vert usefull. I had the crank position senser spot on 0 degrees btc. And thought the ignition advance is taking cAre of by the microplex. As long as 6 months my car was jerky at low speeds and shuddering on the highway. Yesterday i moved the sensor anti clickwise (earlier) some degrees (no tools available because on vacation) and huge difference. Thanks for the note Dr.Jeff. Need to do it with a light when back at home.
 
Definitely check it with a light as soon as you can. Too advanced will cause detonation, the death of a turbo engine.
 
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