kmetiuk
10+ Year Contributor
- 521
- 125
- Mar 10, 2010
-
Edmonton,
AB_Canada
I am stumped here. One night fine, next morning not. Zero changes to the car. It did drop from +8C to -10C overnight tho so I'm feeling like the temp change broke something or somethings not happy now.
Anyways, I went out to start my car and after warming up it started to very slowly go lean. The night before I was driving it and my AFR's are all bang on across the whole range. Idle-crusie-wot. All fine and bang on target.
After it was warmed it up and while I was looking at my log from the night before; the the car starts going lean.... very very slowly. Over about 2-5 minutes it went from combinedFT of ~0% to pegging it at +17-20% at which it stopped trimming and the AFR went very lean (16-17) and you could could here it running funny so I shut it down and upped the VE table (which I knew already was weird). I restarted and the AFR went back to normal and the combinedFT was down closer to 2-3%. But my VE cell at idle was 81% which I know is fuuucked. So I started diagnosing is going on.
Back story: Freshly built motor with ~800km's on it. Still on break in mode. New everything: from guides to pan it got all the HD bits. Running a bit more boost since 500km's but no knock and my EGT's are in the 800-850C range. Not burning oil nor coolant. Rebuilt the Holset about a week ago or more. Tested out fine and running normal. Haven't done a comp test as the valves all got recut and I am waiting until ~2000km mark as I have read it takes quite a while for valves to fully seat in their new homes. All the fun bits and properly cleaned up and regasketed all around. Freshly rebuilt 1G NA TB about 8 months ago. I only have a few couplers on my intake as I welded where I could and put couplers where it made sense.
Sooooooo its running fine one night and the next morning not. AFR's were all bang on before and now its lean across the whole range. Literally looks shifted up by say 2-3 "AFR's".
So far:
- Fuel pressure? Since its shifted up along the whole range. Bang on. Clicked it on with DSMLink and checked. Still a rock solid 43psi right where I left it. Turn engine on drops down to low 39-38 right where it usually likes to site at idle. Give it arev up to launch limit and get a few lbs of boost and I can see my gauge rising about 1:1. Dunno for sure as I should log it but it looks right. Nope.
- Vac line popped off? Did a BLT to 35 psi. Holds it fine. Found one little spot where it was very slightly doing that foam thing at highAF pressures so I fixed that. Tested every connection, hose, BOV, WGS solenoid, TB, IM, and anything else seeing boost/vac signal. Notta. All sealed still. Nope.
- Fuel Leak? Checked all connections from tank to rail and back again. No leaks. Not on the injectors themselves nor on any AN connection. All fine. Nope.
- Plugged fuel filter? Pressures suggest its fine but I pulled it out anyways. Aeromotive rebuildable one. Pulled it apart and its pristine inside. Nope.
- Bad injector? Need to test more as all I did was shut off each one individually in Link and listened for a change in idle and I can confirm that change. They seem fine. Plus it seems weird that this issue pops up only after its warmed up and progresses slowly until its out of fuel trim.
- Bad O2 sensor? Well when it hit 16-17 at idle it sounded knockie. Knock sensor doesn't pick it up b/c its disabled below whatever the defaults are in DSMLink. It sounded like marbles in a tin can....like very lightly which I believe it what knock actually sounds like. Hence why I shut it off. Also I went for a careful cruise around the block and the AFR's are going lean and NOW it knocks at even light throttle and its got no power and the EGT's are high from the ECU pulling timing from the knocking so I feel like the AFR's are actually lean and the O2 is fine.
- Some kind of leak? Posible given the 20* temp change overnight. BLT showed nothing tho and I mean I checked from brake booster to BOV. Nothing. Holds a solid 35 psi with no leaks.
- On the leak thing....so it would be lean at idle and rich under boost but I am seeing lean across the whole range...boost or vac same lean condition.
Here's the weird part: If I turn down my fuel calibrated fuel trim from -73.8% to -67% (so that it injects more fuel than it should with a bigger pulsewidth then the AFR's line. I went for a crusie like that and it FINALLY builds boost and pulls hard. But again if I leave it like this then it slowly starts going lean and I have to change the global fuel again. To be clear I am just changing the global fuel to diagnose the problem...its not a fix and had already been reverted. Just need to see if it was in injector which by upping fuel I can see its not. I think it it was an injector then it would have stayed lean no matter how wide the pulse width but I didn't see that.
So this ALL leads me to either pump or AFPR. I haven't ruled out anything yet but this is where I feel the issue must be. It feels like a fuel delivery issue.
I saw a post about issues with an AFPR where there was damage inside from a little ball or something. Can't find the post now but if you know of it could you link me plz? I am gonna pull it apart now to verify its okay anyways.
I don't know how to test the pump (wally 400 with less than 20K on it) past what I have done. It sounds like usual. Normal amount of cranking at start up. Base pressure unchanged and where it always is. Idle pressure fine. What looks like a 1:1 rise rate. What other test can I perform on it?
I'm pulling the pump now to check its filter sock and check inside the tank to see if I got some bad gas and it gelled up inside the tank. I have fixed and cleaned small lawnmower engines that had some weird gelled gas in them but I am reaching for straws there.
I am going to blow out the fuel lines while I have all this stuff of to verify they aren't plugged and also pull the rail and the injectors and check their filter baskets too.
If AFPR looks fine and the pump/sock filter/gas tank are fine then anyone else got any ideas? I'm struggling to find more culprits after this.
Anyways, I went out to start my car and after warming up it started to very slowly go lean. The night before I was driving it and my AFR's are all bang on across the whole range. Idle-crusie-wot. All fine and bang on target.
After it was warmed it up and while I was looking at my log from the night before; the the car starts going lean.... very very slowly. Over about 2-5 minutes it went from combinedFT of ~0% to pegging it at +17-20% at which it stopped trimming and the AFR went very lean (16-17) and you could could here it running funny so I shut it down and upped the VE table (which I knew already was weird). I restarted and the AFR went back to normal and the combinedFT was down closer to 2-3%. But my VE cell at idle was 81% which I know is fuuucked. So I started diagnosing is going on.
Back story: Freshly built motor with ~800km's on it. Still on break in mode. New everything: from guides to pan it got all the HD bits. Running a bit more boost since 500km's but no knock and my EGT's are in the 800-850C range. Not burning oil nor coolant. Rebuilt the Holset about a week ago or more. Tested out fine and running normal. Haven't done a comp test as the valves all got recut and I am waiting until ~2000km mark as I have read it takes quite a while for valves to fully seat in their new homes. All the fun bits and properly cleaned up and regasketed all around. Freshly rebuilt 1G NA TB about 8 months ago. I only have a few couplers on my intake as I welded where I could and put couplers where it made sense.
Sooooooo its running fine one night and the next morning not. AFR's were all bang on before and now its lean across the whole range. Literally looks shifted up by say 2-3 "AFR's".
So far:
- Fuel pressure? Since its shifted up along the whole range. Bang on. Clicked it on with DSMLink and checked. Still a rock solid 43psi right where I left it. Turn engine on drops down to low 39-38 right where it usually likes to site at idle. Give it arev up to launch limit and get a few lbs of boost and I can see my gauge rising about 1:1. Dunno for sure as I should log it but it looks right. Nope.
- Vac line popped off? Did a BLT to 35 psi. Holds it fine. Found one little spot where it was very slightly doing that foam thing at highAF pressures so I fixed that. Tested every connection, hose, BOV, WGS solenoid, TB, IM, and anything else seeing boost/vac signal. Notta. All sealed still. Nope.
- Fuel Leak? Checked all connections from tank to rail and back again. No leaks. Not on the injectors themselves nor on any AN connection. All fine. Nope.
- Plugged fuel filter? Pressures suggest its fine but I pulled it out anyways. Aeromotive rebuildable one. Pulled it apart and its pristine inside. Nope.
- Bad injector? Need to test more as all I did was shut off each one individually in Link and listened for a change in idle and I can confirm that change. They seem fine. Plus it seems weird that this issue pops up only after its warmed up and progresses slowly until its out of fuel trim.
- Bad O2 sensor? Well when it hit 16-17 at idle it sounded knockie. Knock sensor doesn't pick it up b/c its disabled below whatever the defaults are in DSMLink. It sounded like marbles in a tin can....like very lightly which I believe it what knock actually sounds like. Hence why I shut it off. Also I went for a careful cruise around the block and the AFR's are going lean and NOW it knocks at even light throttle and its got no power and the EGT's are high from the ECU pulling timing from the knocking so I feel like the AFR's are actually lean and the O2 is fine.
- Some kind of leak? Posible given the 20* temp change overnight. BLT showed nothing tho and I mean I checked from brake booster to BOV. Nothing. Holds a solid 35 psi with no leaks.
- On the leak thing....so it would be lean at idle and rich under boost but I am seeing lean across the whole range...boost or vac same lean condition.
Here's the weird part: If I turn down my fuel calibrated fuel trim from -73.8% to -67% (so that it injects more fuel than it should with a bigger pulsewidth then the AFR's line. I went for a crusie like that and it FINALLY builds boost and pulls hard. But again if I leave it like this then it slowly starts going lean and I have to change the global fuel again. To be clear I am just changing the global fuel to diagnose the problem...its not a fix and had already been reverted. Just need to see if it was in injector which by upping fuel I can see its not. I think it it was an injector then it would have stayed lean no matter how wide the pulse width but I didn't see that.
So this ALL leads me to either pump or AFPR. I haven't ruled out anything yet but this is where I feel the issue must be. It feels like a fuel delivery issue.
I saw a post about issues with an AFPR where there was damage inside from a little ball or something. Can't find the post now but if you know of it could you link me plz? I am gonna pull it apart now to verify its okay anyways.
I don't know how to test the pump (wally 400 with less than 20K on it) past what I have done. It sounds like usual. Normal amount of cranking at start up. Base pressure unchanged and where it always is. Idle pressure fine. What looks like a 1:1 rise rate. What other test can I perform on it?
I'm pulling the pump now to check its filter sock and check inside the tank to see if I got some bad gas and it gelled up inside the tank. I have fixed and cleaned small lawnmower engines that had some weird gelled gas in them but I am reaching for straws there.
I am going to blow out the fuel lines while I have all this stuff of to verify they aren't plugged and also pull the rail and the injectors and check their filter baskets too.
If AFPR looks fine and the pump/sock filter/gas tank are fine then anyone else got any ideas? I'm struggling to find more culprits after this.