410 replies to this topic

[Barbbachello]

Alternator is piss easy to remove. CTS is right behind it.

Does coolant piss out when you remove the sensors?

[Jimbo]

I would hazard a guess and say it's more than likely considering the coolant crossover is plumbed directly into the radiator. It's connected to the header tank aswell so if it did piss out, the gravity of the coolant flowing downwards would cause it to leak at a pressure, so it wont draw air in to cause an air pocket. Probably just need to top up the header tank afterwards. 

I think it's a job where sleight of hand with a quick sensor change would avoid too much loss of coolant.

[allpaw4]

Just make sure the radiator cap is left on. Keeps sort of a vacuum on the Cooling system then.

[RX25SE]

Are CTS faults common on these?

[RX25SE]

While the CTS has a huge impact on the volume of fuel delivered, with other makes they do not usually give any trouble (sensor itself). From what you mentioned Josh, B4's are no different.

 

As the car is throwing a system lean code , P0171, should the CTS circuit be at fault it should be signalling the ECU with a lower than normal voltage. This could be due to a partial short to ground on the signal wire (the other wire should be permanently grounded via the ecu) or a poor connection somewhere.

 

Might be worth checking the signal voltage at the sensor with the engine at operating temp (or checking the pin at the ecu) and seeing if the voltage is in range. You could use a scan tool to read live data and see what the CTS is reading in terms of deg.C also.

 

@OP Does the car flat-spot when cold?

 

 

Im still thinking air leak at this stage. Has the ducting from the MAF to the throttle been checked?

[LukeFranky]

Thanks guys.

 

I suspect it is still an air leak and I have an idea where. You may not recall, previously in this thread I mentioned that I unseized and rebuilt the primary turbo after it's replacement blew apart quite while ago. Last I checked there was no shaft play so it seems to be holding up despite the fact I didn't have the tools to balance it. Anyway, as you may guess I had the snail shell apart, well I had the whole thing in pieces, but where the shell joins the back plate is the most plausible location for an air leak now.

 

The car does have flat spots and the odd hesitation once in a while. It struggles the most if I go to WOT near VOD revs. If I go WOT from low revs the VOD is nearly non-existent. Down shifting into the VOD zone to overtake can really make the car bog down until secondary engages. You can really feel the car struggle the most at high boost on primary, except if you gun it from low revs.

 

I've got a cam shaft sensor on it's way. I will smoke test the entire intake and exhaust system as soon as I get a chance. At least I've got a game plan and not quite ready to just give up.

[duncanm]

 

The car does have flat spots and the odd hesitation once in a while. It struggles the most if I go to WOT near VOD revs. If I go WOT from low revs the VOD is nearly non-existent. Down shifting into the VOD zone to overtake can really make the car bog down until secondary engages. You can really feel the car struggle the most at high boost on primary, except if you gun it from low revs. 

 

I suspect you're just seeing the behaviour of the VOD there..  not anything malfunctioning.

[RX25SE]

I've got a cam shaft sensor on it's way. 

 

 

I doubt this will fix it. Sorry.

Typically the cam sensor is used as a cross reference to the crank sensor so the ecu can determine which TDC is which, ie. cyl1 firing or cyl4 firing. (remember the crank does two revolutions to the cams one revolution) This is needed to time spark and the injectors to open at the correct point in the engines cycle.

 

 

 

Has the ducting from the MAF to the throttle been checked?

 

?

[LukeFranky]

I doubt this will fix it. Sorry.

- I don't expect it to fix the main issue, but I have learnt that if you know about a problem you should fix it first.

 

Has the ducting from the MAF to the throttle been checked?

- Not properly yet, but I plan to, and also going to smoke test my exhaust system.

[RX25SE]

 I have learnt that if you know about a problem you should fix it first.

 

Based on the fault code?

[allpaw4]

After having experienced a code thrown by a faulty cam sensor, and reading about the symptoms, I'd agree and say change the cam sensor and then see what it does. I will bet it will cure the hesitation and flat spots mentioned, although it will do nothing for the VOD issues. You change gears into that zone and it's going to be slow and hesitant.

[allpaw4]

If you change the sensor and still have codes, look at the wiring under the manifold and the main plugs, I think they are Gray and brown.
A squirt of CO contact cleaner might help. Make sure you do not use NF. Only CO, as the NF will melt the plastic for you.

[LukeFranky]

I'm changing the cam shaft sensor based on the code and history I've had with it. It originally played up quite a while ago. At idle with the head lights on the engine light would flicker on and off alongside a misfire. Because it was only occurring with the lights on someone suggested it was a bad earth. I added the earth and the problem disappeared altogether and I stopped worrying about it. Well now the code has come back even with the extra earth attached.

 

Anyway, I smoke tested the entire intake last night. There was very minor leak near the secondary turbo's pressure relief thingo. Tightened up the clamp and it disappeared. I doubt it was even a problem. Nothing else leaked but I was unable to get a large amount of pressure in there because my stopper kept blowing out. I think everything is air tight unless something is opening up under high pressure.

 

I also changed out the CTS. 

 

Disappointment. Still too lean.

 

I think now it would be useful to summarize the symptoms:

1. Code is bought on by primary boost. Typically highway driving under load uphill.
2. Likewise, engine light tends to disappear when manifold is under vacuum.
3. Once I hear the BOV totally shut, the boost pulses, it now pulses anywhere between 2psi and 7psi.
4. I have been able to hear a slight high pitch whistle from the left side of the car.
5. Car used around 13L per hundred on a warm afternoon. It used over 15L coming back in a colder evening.

Any idea what could cause the pulsing? MAP sensor? This is only a relatively new symptom.

 

Some other things that might be worth mentioning:

• Non-stock secondary turbo - a new turbo made for an older JDM legacy, very similar to stock. I can get the VF number if necessary. Doubt it has anything to do with the issue as I'm not even using the secondary when the problem crops up. I do have the original secondary which I don't think has anything wrong with it. This new turbo was put on with a matching primary which was actually faulty and blew up.
• When gradually building revs, the car makes a funny noise in the exhaust during the change over. Sounds like the valve opening. Probably normal. Always done it.

[Robbks]

OK, test time.

Disconnect boost control to primary turbo, plug it up and go for a drive,
replicate the driving conditions and see if the pulsing still occurs.

CAREFUL, your right foot is your boost control.

This will help isolate if it's caused by intake, exhaust or BBoD areas.

Next step is to connect a direct Manifold Pressure source to the primary WG actuator and run the same test.

I still believe it's airflow related and not MAP, CTS, Crank, etc

[Robbks]

I'd hope so,

I've been baning on about cleaning, checking and replacing every line at the FIRST thing you ever do when you have TT issues for pages and in every Thread i've tried to assist with...





but y'know, what do i know anymore..

[LukeFranky]

I assume disconnecting boost control to the primary turbo simply involves connecting the waste gate directly to the turbo and removing the extra line?

 

Vac lines have been reasonably inspected, but quite a while ago. Anything dodgy was replaced but now I'm thinking of replacing the lot to be 100% sure. I do have 3mm hose at home, is that too small? I think the current ones are 4mm.

[LukeFranky]

Should I remove the restrictor pill that lives before the waste gate?