^^^ Thanks for noting that, which I'd missed from product page priced as each. Just now edited my prior comment with correction...

 

Just a thought about your starting and idle issue... Assume that the head and cams were redone. This is old school engine building stuff. A performance cam will have more overlap between the intake and exhaust which will have the effect of reducing the compression ratio, in the form of cranking pressure, when the engine is cranking and at idle. This can lead to harder starting and rougher idle. Also, porting the head for better air flow (eg: higher maximum air flow) can lead to lower performance at low RPM because of lower air flow rates.

Just something to think about when chasing this issue and it maybe something that just is that way.

 

Sorry, I wasn't clear about that being a set of 4. Great deal if they hold up well. I think they will given that they are originally for the Audi TT.

 

@ECSTuning sells 550cc injectors for 280 with the adapters for the mini. I was planning on going with the 380 Audi ones but decided that will probably add more mods down the road so the 550 will suit me better. Just my 2cents. Will need a retune though if it was not tuned originally.
https://www.ecstuning.com/Mini-2005-...jectors/550cc/

 

Whether or not cylinder head mods were performed remains conjecture. I wrote the PO again 2 weeks ago, asking (2nd time) to please contact me if finds the missing build docs or even can provide insight by recollection but no response. From what I saw when purchased, more likely than not he reached deep without spending restraints to surpass JCW specs. If so, why stop at bolt-on external parts? Seems illogical plus this was his 3rd special-ordered R53, thus was familiar with them.

Project today was to see what I could learn using the Foxwell NT510 Elite scanner I bought last November but kept in the boot unused. No codes were showing on the dash but the scanner picked up (2) unrelated to engine tune, those being; Body Control Module ZKE (BC1) and Instrument Cluster KOMBI - both with Fault 5. Unsure what caused those but I cleared them anyway. Next, determined ECM data per file screenshot, which just seems confirms the it's the OEM module for this VIN. I don't see a way to determine from Foxwell scan if that ECM had been flashed or has OEM parameters. I then drove up the mountain (1k' elev gain) prox 45 miles roundtrip, returned home and rescanned to confirm no fault codes. The car started more quickly cold with less hesitation, however ambient was much warmer today than recently. Engine idles smoothly and pulls strongly. What fun with windows down, cd player cranked up and Milltek crackling and popping!

 

Not knowing what was available for the Minis when this car was built, something popped into my head while reading your posts. I had a sports car at one point that had the heads/cam/intake upgraded but rather than swap injectors, the po had installed an adjustable fuel pressure regulator and cranked up the pressure. The theory being, at a higher fuel pressure than oem the oem injectors spray more fuel with each pulse. Do S model Minis have a FPR on the rail? If so, has yours been tampered with?

 

Lucky you!
Still waiting for that day here in the NE...

 

Without removing the intercooler, can't see much beneath. I was surprised and pleased I could see the #1 cylinder injector to identify size. Yes, the W11 S-spec engine utilizes a FPR which is not adjustable, noting the Bentley manual outlines procedure to check factory spec of 50.8 +/- 3 psi. Not gonna do that. My thinking before identifying the OEM 330cc injectors was that it had too large 500cc range injectors, which might be root cause of cold start hesitation but I'm now thinking the opposite, i.e, needs larger injectors. If so, I'm seriously contemplating ordering a set of genuine JCW-spec 380cc, having read OBS's related post this morning WRT his good deal price found. Also noting, I am currently running JCW-spec colder NGK spark plugs, which didn't help with cold starting vs the prior set of plugs.

 

Not sure a larger injector will help with cold start or idle... My understanding is that the larger injectors were needed at the higher end of the RPM/HP range when higher fuel flow rates are needed, such as when there is a tune on the car. Cold start/idle shouldn’t be max-ing out even the smaller injectors. If neither are max-ed out, then they both should perform the same.

Now the colder plugs, as you noted, are an issue...

Have you thought about taking data with an app like Dash Command? It might give you a better idea of what to look for.

 

Eddie, thanks for your injector perspectives which makes sense wrt starting and low rpm no-load demand. All my thinking to this point had been towards injectors being too large, thus sluggish starting. Having determined what's actually in there, I should have considered that aspect more fully. To clarify, the engine idles smoothly once past initial cold stumbling stages. Changing to 380cc appeals, however the expression "if it ain't broke..." might apply until more is known.

The cold starting symptoms have been there since I bought it with spark plugs apparently replaced at time of mods. Those were NGK BKR6EK, which are not W11 application fitment and since "6" vs "7" heat range, clueless why they replaced the OEM plugs. Figuring the engine "needed" colder plugs with the 4-1 headers/hi-flo cat, pulley and CAI at minimum I bought (genuine from NGK direct) JCW-spec BKR7EQUP which did nothing to improve (or worsen) cold starting.

Unsure what an OBD phone app might reveal that Foxwell's NT510E scanner (or similar model) does not. The scanner allows "Live Data" logging and saving, however I wasn't successful exporting that in print file format same as the ECM data. That live data included fuel trim levels, although that info wasn't intuitive to me. I carry the scan tool in the boot if a fault code pops up while driving, with quick and easy reason(s) determined.

 

Colder plugs are used with higher boost, nitrous, etc. If it has any work done that would increase cylinder pressure the po may have installed them at that time. I believe the pulley kits come with plugs that are one heat range cooler.

 

^^^ Agreed but question remains why different NGK plugs of same OEM spec MCS (non-JCW) heat range were installed at time of mods (just engine break-in miles at that point) or some time after. The plugs I removed were the hotter "6" vs colder JCW-spec "7" in now. I used NGK's plug comparison utility on both plugs, which revealed the ones I removed have identical dimensions but made from slightly different materials (platinum electrode on BKR7EQUP vs nickel on BKR6EK).

 

So the plugs were replaced by the OP. The replacement plug was of the “S” heat range “6”, but of nickel instead of platinum. And the car was new enough that OEM plugs should have been almost brand new and not needing to be replaced. This makes little sense, is what you are thinking...

Make little sense to me either. But here is a speculation - When the work was bing done, a plug was either lost or damaged. The replacements (non-OEM) where what were readily available and/or were less expensive. I remember going out to purchase plugs for our R50 and had difficulty finding a place that carried the right plugs for the car. I wonder if they ran into the same issue. It would have been in the same time frame as I had my issue.

There is also a lot of discussion on NAM about what plug is better in a MINI. But that discussion usually centers around which brand is “crap”, not what to use within a brand... But, could the person who did the work think the non-OEM plugs were better? Not sure that could be, but who knows. Usually the platinum plugs are considered to be better.

That aside, I think your other statement about putting in the “7” plugs answers the question... Are the plugs an issue with respect to the cold start and idle issue you are having? The answer seems to be “no, they are not”. So, it would seem something else is the culprit. BTY - in thinking about it, my statement about the plugs is likely wrong (it seemed right at the time ). In thinking about it, plug heat range is kind-of like the injectors. The heat range (one point either way) should make little difference at low power levels, such as starting or idle. The idea is to keep away from knock, which would be more prevalent at higher power levels and RPM; full throttle. This would be why the JCW goes to a colder plug. At idle and starting the JCW is otherwise no different from the S. Hence, putting in the JCW plugs you found no difference with the cold issue...

Does the Gen 1 SC engine have a blowoff valve? Or something similar that allows recirculation of boost pressure when cold? On my R56, I see a difference in intake pressure (I have a ScanGage II hooked up) from starting until the engine gets to about 110 deg. So my engine has something that changes with engine temperature at some point. This only happens when the car has been sitting a while, like over night. It doesn’t create any real issue, but there is a difference in how it runs. On your engine, if there is a system like the blowoff valve on the R56, could there be an issue with that?

As for data taking, it sounds like your scanner would do the same as the app. I would look at things like manifold pressure, boost pressure, fuel ratio, etc, and compare what they look like when the engine is cold and having the issue and when it is not having the issue. This may give a hint as to what the issue is...

 

^^^ A lot of thoughts and consideration of related aspects contained with that reply!

As to the spark plugs change, I hadn't considered possibility of one being lost or broken. If that was so, seems implies if not confirms the cylinder head had been removed during that mod work, otherwise no need to remove the OEM plugs which would have been shielded from damage within their respective tubes. Unsure about a blow-off valve but "assume so" until I check my Bentley manual later to confirm.

As to manifold pressures, I just completed tests with the Foxwell NT510E scanner reading "Live Data" and saving that to files (OBD2 Cold, Warm & Hot). As said yesterday, can read those on the scan tool and also on computer using FoxAssist utility but can't export that as printable (or not) files. So instead, I took some readings at various coolant temps and rpms as follows:

Intake Manifold Absolute Pressure>>>>>>>>>>>5.2-6.1>>>>>>4.1>>>>>>4.1

Coolant temp (F)>>>>>>>>>>>>>>>>>>>>>> 91*>>>>>>>160*>>>>>210*

Engine RPM>>>>>>>>>>>>>>>>>>>>>>>> 870 (idle)>>>>>4000>>>>5000

The above manifold pressure readings were at steady state rpms with minimal boost. I then did several quick throttle bursts towards but well short of redline and read pressure readings in the high teens with one quick burst showing 20.4 psi @ 216* F. Unsure what max boost might be, however not gonna test that under no-load conditions.

 

Isn't stock boost ~11 psi? Sounds like you're right on target for a stock setup.

edit: or is it 10 psi for stock? I can't remember what I've read in the past.

 

I was seeing much higher than that on the scan tool in live data as recorded above. I subsequently deleted my observation after realizing the file extract reverts to default metric values vs imperial which I was displaying real-time. The quoted 25psi was actually 25kPa (3.63psi) which was at low rpm and without throttle burst.

 

Ah, okay. That makes sense. I hadn't really kept up with your thread.

It kind of sounds like the open-loop tune is a bit off, but I guess without knowing what mods you have that's difficult to figure out, which means I'm just repeating what you already know.

 

^^^ Unsure what you meant by "open-loop tune being off", so insights welcomed...

Kept thinking manifold pressure should be zero or less at idle, so went back out and retested that aspect. This time within Live Data, just toggled the desired attributes to avoid scrolling through too many fields with varying readings while noting those. Nope, boost consistently correlates to the first set of readings, i.e., positive values at idle at all temps. Still don't know what size reduction pulley was installed.

Coolant temp F*>>>>>>>>>>>>>>>>>146>>>>>154>>>162>>>167>>>180>> >183>>>194
Short Term Fuel Trim - Bank 1>>>>>>>>>8.6>>>>>7.0>>>>6.2>>>7.7>>>7.8>>>>??>>>??
Manifold pressure PSI>>>>>>>>>>>>>>5.4>>>>>5.4>>>>5.4>>>6.4>>>6.4>>> >6.4>>>5.2
(?? = not noted)

Also checked:
Fuel System A Status: CL (Closed Loop?)
Fuel System B Status: -- (which I assume means N/A)
Re-scanned for Fault Codes (none found)

 

His comment is related to the tune itself I believe, in which open loop uses the O2 to control AFR and closed loop does not. When at full throttle, the ECU tends to go "closed loop" using pre-populated data in the air/fuel tables.

Your second comment on boost has me perplexed. The boost values should be negative at idle representing a vacuum condition. Did I misread or misunderstand?

 

Yes, positive boost numbers at idle shown without minus symbol in front of displayed PSI value. The pulley looks small. I'll try to get a mirror in there and see if any markings or measure the diameter roughly. Positive boost values at idle might correlate to 20.4 psi seen once during throttle burst tests.

Edited as relates to my subsequent better understanding of MAP vs Boost

 

Hmm, wonder if you've got a bad or improperly calibrated throttle body. If the blade is almost closed at idle, that could be the reason for no vacuum. With no vacuum, the BPV closes as well.

 

Yes. The DME runs in open loop at startup. It just pulls from tables rather than using the O2 sensors that aren't warmed up and operating yet.

Aren't you reading in absolute pressure? 5 psi would be like 19 inches Hg of vacuum, which is normal if memory serves.

 

deepgrey is correct. With absolute pressure, the readings for atmospheric pressure is 14.7 psi at sea level. A reading less than that (at sea level) is what would be called a vacuum. So, your readings of 4 or 5 psi constitute a vacuum reading. Boost is any reading above 14.7 psi. So, if your system is designed for 10 psi of boost, then your reading at absolute pressure should be 24.7 psi. Hope that helps.

 

Very happy to determine (from you 3 guys) no issues with the TB as well as being schooled how to interpret manifold pressure readings! Frankly, what I was seeing concerned me as contrary to street performance reliability and driving manners! Just now went out again and took this image showing combo of coolant temp, manifold pressure and idle rpm. I'd really enjoy having one of those OEM accessory boost gauges not otherwise included in the optional Chrono pkg.

Also noting I'm at 5k' elevation with unseasonably warmish ambient temps today (79* F when pic taken) which I realize affects actual pressure...



As long as I'm in "school" today, just now watched this interesting tutorial video by AEM:

 

I had another thought. I haven’t read the whole thread, so it may have already been mentioned. Early on I think you mentioned the seller quoting 230 hp to the tires. From my idle reading of NAM over the years, I’m pretty sure the stock 330 cc injectors hit 100% duty cycle long before that number, so something doesn’t add up.