I was going to suggest this yesterday, have you confirmed TDC on the crank pulley is also TDC on the cam pulley?
Yes I'm sure. I'm familiar with the sound as when I have heard the sound, usually under load (Not just normal driving) I would pull my DET sensor bypass out and the sound will completely stop under load and all... It happened going up the mountain and I had to pull over to take out the DET sensor bypass. It's not just low boost... It's no boost! she's an NA which makes it more interesting I was talking to a mate at work who is very knowledgable in mechanics I'm general... He's built an engine or two to high HP specs He has suggested it could be now a fuel related issue. Whichs would make sense as its the last thing I guess I havnt replaced. I'm talking about the fuel reg's, injectors (I've only replaced the O rings and pintal caps thus far) and the fuel pump. His theory is perhaps a fuel pressure issue under load... It perhaps is leaning out and resulting in pinging. It can only be the reason now.... I hope Before you ask I have ran 98/95 for years! 91 has never so much as touched the fuel filler :rofl: Ill buy some fuel reg's and run a fuel pressure test.
The EGR is new and working... The FPCU isn't bypassed nor do I think I have issues with it... It's never not started or played up
I'm guessing you don't have a wideband O2 sensor installed. That would be my next suggestion. If the timing is confirmed good the only other explanation is fuel. Another suggestion though. Ecutalk does logging. Take it for a drive at the speeds/loads where it would ping going up hill but doesn't, then do the same going up hill, import the logs to Excel and see if there is any significant changes at the same speed points where it pings.
I know you have EGR, which is why I suggested it [TIS] And just because you have not had issues with FPCU (or think you have not had issues), doesn't mean you shouldn't check it. It is a simple bupass. It is a 20+yo electrical component. Have you pulled the plugs at all?
Yeah didn't say I won't look at it lol but definitely adding it to the list of things to check. Is there a test to perform on th FPCU to confirm if its good?
A wideband O2 sensor and guage will tell you real time what your air/fuel ratio is, ie wether or not it's leaning out. If you have this installed and go for a drive, and notice the air fuel ratio changes from around 12-13:1 to say 15-17:1 when it's pinging, then you've clearly identified your problem is fuel related, ie leaning out. Now you can start trying to fix this, each time going for a drive and monitoring your air fuel ratios real time to see what works and what doesn't. ie takes out the guesswork. Some wideband O2 sensors will also allow you to do logging on your laptop. So you can log this along with ecutalk then import and merge them together into Excel.
While checking the afr will be a good check, you are basically taking the average afr of 3 cyls, so if for example, an injector is blocked and the other 2 are fine, the 2 good injectors will mask the bad. Don't ask how I know.
Cool Cool! thanks for the feedback guys! very helpful. I have new O2's in now...I don't particularly want to go spending more on Some Widebands although I see the benefits, ID much rather use that money to replace fuel related components. So what I'm going to do I know which sounds crazy I know. Is just swap out the fuel reg's, FPCU, and the Fuel pump...I'll test the injectors and possibly swap them out too with new ones. All of the above will be New parts! no stuffin' about! If they didn't need replacing, after a quarter of a century of use, the might go soon fail anyway....So in a way its preventative maintenance which is what I've always been about
Waste of money, If the fuel pressure is fine the system is fine. Buy a FP guage and drive with it for a few days and keep an eye on it.
Yep, either go twins, or install two bungs, one per side, so you can swap the sensor over to check both banks. Oops, just re read your post. Yes I agree but it should still show up as a problem that you then investigate further.
This too, and this is much cheaper than widebands so a good first step. Personally I think the first mod anyone should do when modifying anything to do with the engine (especially for turbos, yes I know you're NA lol) is install a wideband sensor.
Cam, I went through this.... It was a painful experience in my old NA. Light throttle pinging, on warm days. Tried everything you have done, and more. Changed pretty much every sensor, new injectors, new fuel pump, checked fuel pressure at idle and while pinging etc etc..... Nothing helped. The only way I could solve the problem was to get a custom tune and knock out some timing in those problem area's. Using Datascan, I was able to trace which cells in the timing map (the A/F ratios were fine) were the problem areas. The cells accessed in those light throttle areas have ignition timing of about 45 degree's. I had to knock them down to about 35-36, to remove the pinging. But be careful, drop them too low, and you can increase your exhaust gas temps. Anyway, I had it done on a dyno. The car still ran fine with the reduced timing, and there was no loss of power because as soon as you blip the throttle to accelerate, you access different cells, usually in the open loop portion of the map. I have not heard of any TT's suffering from this type of pinging, even though the timing maps are very similar. TT's tend to ping more under high boost or high throttle conditions. But remember that the NA motor is a higher comp motor than the TT, and all things being equal (ie, low throttle, warmish weather, no boost), the NA will sometimes ping in those high ignition timing cells. It was a trying time, but modifying the timing map did help. And the fact that the removal of the DET sensor bypass seems to resolve the issue, indicates that you too may have to adjust your timing map to cure the ping gremlin. It
^^ there you go, sounds like this may be your problem, you can easily verify this by logging using ecutalk as per a previous post and analysing your timing numbers.
Use the datascan Map Trace feature... It shows you in real time which cells of the timing map (or fuel map) are being accessed as you drive.
Thanks Matk for that... I knew you had the same issues trying to find why you had a ping issue. Seems so weird though that after swapping out the flogged crank sprocket that I would have these problems... You would think I would have had problems with that the way it was. But no, I'm having problems with it in the correct position If I just retard the base timing a bit, wouldn't that help? Or no?
