Wtf!

[Daboss]

Hey forum I am really puzzled as some weird issues are going on with my ride. Can see my other post, http://www.skylinesaustralia.com/forums/We...No-t316378.html, to get up to speed. In short had an issue car missing on cylinder 3 and seemed to stem to other cylinders. To solve this problem I removed the pfc and tried the stock ecu just as a test, to my amazement the car started all cylinders were firing and the afr's were in the high 16's to mid 17's. took the car on a cruise while watching the afr's and they were pretty normal under vacuum normal cruise load they were varying but trying to stay within the 14.7 range. On decel the car pops and gurgles and will get a small backfire from time to time but no black smoke and afr's seem normal. Now here is the messed up part the car has a q45, z32, supposed high flowed injectors to 650 they are said to be flow matched within 1.3% of each other, a 35r and aftermarket plenum with exhaust manifold. How the hell is this possible? How can the stock ecu start the car with the z32 and bigger injectors much less run smoothly? I even gave it a bit of a boot in second gear to see where boost started to build, plus check out the afr's, and positive pressure began at 3000rpm which was to be expected and to my surprise afr's were in the 11's, I think, this is flat footed in second gear starting from around 1500 or so rpm. Will make sure about the afr readings tomorrow after another drive. The car idles kinda lumpy but I am using old spark plugs that are a variety of heat ranges, types and one or two of them were the ones were the cylinders were not firing so they were black with soot and got could smell the fuel on them, gave them a good clean up before putting them back in though and made sure all were firing. Will make sure and buy a new set tomorrow and change them out to see if that helps with the bumpy idle. Besides the one time it stalled when decelerating with my foot on the clutch and when starting it up after getting petrol it drives fine, noticed at startup I might have to give it a rev to clear it up and get the juices flowing but aftert that it idles great for what suppose to be in it. What if any explanation can you guys give me? I am suspecting tht the injectors are not high flowed 650's rather just a set of stock injectors, they are red with a single hole for fuel delivery. If that explains the injectors then how can the ecu handle the z32 afm, how can it start idle and run fine with it installed?

Edited April 13, 2010 by Daboss

[paulr33]

no one will bother reading it, format it properly

[PM-R33]

Hahaha so true! I started reading it and gave up half way though

[Cartman]

learn to type something so its readable, all i noticed in that was q45, 35r, 650cc highflowed injectors.

[zebra]

I read the last 2 lines and it hurt my head....

[DRD-00F]

I got as far as the link...

[Daboss]

Lol wow forum never ceases to amaze me. Here I am thinking I have a hot topic, 5 replies and so quickly but everyone is commenting on how it is written. WOW!!!!! Anyway's here I go again

Hey forum I am really puzzled as some weird issues are going on with my ride. Check my other post to get up to speed, http://www.skylinesaustralia.com/forums/We...No-t316378.html. Quick version, car was missing on cylinder 3 so I did all the test I could think of with no luck, after test conculded another cylinder now was missing. For testing purposes I removed the pfc and tried the stock ecu, to my amazement the car started all cylinders were firing and the afr's were in the high 16's to mid 17's. Let it idle for awhile nothing seemed wrong so took the car on a cruise while watching the afr's and they were pretty normal. Light to mid load the afr's were behaving normally trying to stay within the 14.7 range. On decel the car popsed, gurgled and will get a small backfire from time to time, but no black smoke and afr's seemed normal.

Now here is the messed up part, the car has a q45, z32, supposed high flowed injectors, a 35r, aftermarket plenum and exhaust manifold. How the hell is this possible? How can the stock ecu start the car with the z32 and bigger injectors much less run smoothly? I even gave it a bit of a boot in second gear to see where boost started to build and to check out the afr's. Positive pressure began at 3000rpm which was to be expected and to my surprise afr's were in the 11's to 12 range at wide open throttle, this is flat footed in second gear starting from around 1500 or so rpm. Will make sure about the afr readings tomorrow after another drive. The car idles kinda lumpy but I am using old spark plugs that are a variety of heat ranges, types and one or two of them came from the cylinders that were not firing. They were black with soot and got could smell the fuel on them, but I gave them a good clean up before putting them back and made sure they were giving spark. I am buying a new set today and change them out to see if that helps with the bumpy idle.

Issues I am having if you can call it that are: 1)The car stalled when decelerating with my foot on the clutch. 2)When starting the car up it idles really crappy, I have to give it a rev to clear it up and that seems to get everything cleared and flowing. The idles is a bit bumpy but great considering it is the stock ecu and the upgrades I have.

What if any explanation can you guys give me? I am suspecting that the injectors are not high flowed 650's rather just a set of stock injectors. They are red with a single hole for fuel delivery. That would explain why I am not running rich. The other burning question is how can the stock ecu start and run fine with z32 installed. Abit long winded, but just wanted to give as much info as possible.

[Lukas 33]

Hey Guys,

I am really puzzled as some weird issues are going on with my ride (Check my other post to get up to speed, http://www.skylinesaustralia.com/forums/We...No-t316378.html.)

Quick version:

---------------

Car was missing on cylinder 3 so I did all the test I could think of with no luck. After test concluded, another cylinder now was missing.

For testing purposes I removed the pfc and tried the stock ecu. To my amazement the car started, all cylinders were firing and the afr's were in the high 16's to mid 17's.

I let it idle for awhile nothing seemed wrong so I took the car on a cruise while watching the afr's, and they were pretty normal.

Light to mid load the afr's were behaving normally, trying to stay within the 14.7 range. On deceleration the car popped, gurgled and will get a small backfire from time to time, but no black smoke and afr's seemed normal.

Now here is the messed up part!

The car has a q45, z32, supposed high flowed injectors, a 35r, aftermarket plenum and exhaust manifold.

How the hell is this possible? How can the stock ecu start the car with the z32 and bigger injectors much less run smoothly? I even gave it a bit of a boot in second gear to see where boost started to build and to check out the afr's.

Positive pressure began at 3000rpm which was to be expected and to my surprise afr's were in the 11's to 12 range at WOT, this is flat footed in second gear starting from around 1500 or so rpm.

Will make sure about the afr readings tomorrow after another drive.

The car idles kinda lumpy but I am using old spark plugs that are a variety of heat ranges, types and one or two of them came from the cylinders that were not firing. They were black with soot and got could smell the fuel on them, but I gave them a good clean up before putting them back and made sure they were giving spark. I am buying a new set today and will change them out to see if that helps with the bumpy idle.

The issues I am having (if you can call it that) are:

-----------------------------------------------------------

1)The car stalled when decelerating with my foot on the clutch.

2)When starting the car up, it idles really crappy, I have to give it a rev to clear it up and that seems to get everything cleared and flowing. The idles is a bit bumpy but great considering it is the stock ecu and the upgrades I have.

What if any explanation can you guys give me?

I am suspecting that the injectors are not high flowed 650's rather just a set of stock injectors. They are red with a single hole for fuel delivery. That would explain why I am not running rich. The other burning question is how can the stock ecu start and run fine with z32 installed. Abit long winded, but just wanted to give as much info as possible.

Cheers,

Guythatcantformat

Edited April 13, 2010 by Lukas 33

[TiTAN]

nice work on the reformat.

you may have just lucked out with the combination of your injector size and Z32. the Z32 with standard injectors will make it run lean, the injectors with standard AFM will make it run rich.

[PM-R33]

Hahaha Lukas you must have been bored

[thrtytwo]

WALL OF TEXT

[Lukas 33]

Yeh I was a little bored Trying to put off doing uni work.

PLUS that big wall of text made me angry and I knew if that dude wanted help, he wasn't going to get it if no one could be bothered to read it

[Thelen]

All I can say is take it to a tuner. You should NEVER perform such mods and not take it to a tuner unless you can tune it yourself. From reading other threads, changing injectors shouldn't make any difference per se, as long as you adjust them to a less duty cycle, but certainly a different AFM would make a huge difference even if you adjust it (they are fiddly).

[Lukas 33]

All I can say is take it to a tuner. You should NEVER perform such mods and not take it to a tuner unless you can tune it yourself. From reading other threads, changing injectors shouldn't make any difference per se, as long as you adjust them to a less duty cycle, but certainly a different AFM would make a huge difference even if you adjust it (they are fiddly).

Changing injectors will make it run very rich. It will be injector fuel as a percentage thinking the injectors are 380cc :S

I find it VERY hard to believe you struck it lucky with the z32 and injector sizing, but I don't disagree that its possible.

Man on the PFC you can easily tell the ecu that u have a z32 and calibrate your injectors, so chuck the PFC back in, get some new plugs and try again.

I dont see how the hell the car runs better on a stock ecu, especially with a damn 35r!

[Thelen]

Yea, so basically you need the PFC and a tune to make it work The main reason the injectors probably work stock is a degrade in the line/power cables so that the larger injectors are actually running close to stock. But again impossible to tell really, so tune it

[Daboss]

Ok thanks for the advice guys and thank you lukas 33. Honestly I probably would have never formatted it that way. Do you possibly think the injectors are just standard ones? I am going to put the pfc back in with the 555's it was calibrated for and hopefully the miss stays away this time. I can't get it tuned cause there are no real tuners were I live.

I know the pfc is the better ecu its just that with it installed the cylinders missed and I didnt want to reinstall it and have it all fudged up again. I got the new o-ring for the 555 injector that was missing its own and a new set of spark plugs Will be replacing the ecu, injectors and spark plugs in a few and see how it works out. I hope all goes well.

My thoughts exactly lukas how the hell is it working so well with stock ecu? Anways I am going to replace everything I switched and see how it works out. Will keep you guys posted.

Thanks once again for your help.

Edited April 13, 2010 by Daboss

[lachlanw]

its to do with the % increase in injector size and % de crease in what what your maf reads . if you made your injectors 50% bigger and the maf had 50% lower resolution itll run ..

used to happen with sr20 . put in 555cc injectors and a z32 and it was able to run quite well

[DVS JEZ]

so why start a new topic and leave the other one?

all this writing and you have the same ending as the last topic, your gonna change back to the original injectors with a new o ring and put in some new spark plugs.

[VB-]

change in both maf and injectors means its running ok.

for anyone thats thinking it, no you cant match a z32 with bigger injectors to get good A:F ratio's, the curve of the MAF is different to stock

[JonnoHR31]

so the pfc was set up for 555s, you put in 650s without changing any settings then wonder why it runs like shit? if you have a wideband then put the pfc back in and set it up properly