divadgagnon

That would make a lot of sense. Does anyone happen to know what's the inside diameter of the fuel hose connected to the regulator? I'll try to swing by the hardware store and pickup a few fittings and a pressure gauge before the weekend I think it would be cheaper than buying a kit off of amazon. As for the fuel pump, I did remove the sending unit in february to siphon out the old gas that was in there for over a year and put fresh gas in. Maybe I did something wrong when installing it back in. Or maybe just the fact that I took it out unlodged some crap and clogged the filter. Might try to take it out again to double check everything. It would suck that my fuel pump is going out... I had a AEM high flow pump that I never installed and just sold it a few weeks ago...

The TGV's are gutted, welded shut and ground where the shaft was for the valve plates. The injectors are the same I had on the car before replacing the engine (I kept my original intake) I don't believe they were ever used with E85. It did smell like fuel the first time I ran the engine (before my orignal post) when it was misfiring badly but this time it didn't seem to smell. I'll find a way to look at fuel pressure next time I get to work the car. In the log we can see some misfiring on cylinders 1,3 and 4 at about 395 seconds can this be caused by low fuel pressure? Also is there a reason (other than randomness / luck) why cylinder 2 would be the only cylinder not misfiring? I also have the injectors from the used engine I bought I might try to swap them and see if that makes any difference. Thanks for your inputs guys!

Finally got to work on the car yesterday. I tried to smoke test it but it didn't actually work like I thought it would. I got some smoke in there, but the machine isn't meant to put out any pressure so it filled the hose it was connected to but then started leaking out of the actual body of the machine. Anyway decided to skip this and see what the vaccum gauge would read when running. So I replaced spark plugs, replaced the broken coil wire connector on #3, installed a vaccuum gauge, cleaned the maf and setup the AP to log some data. The car started fine and Idled fine for several minutes, I did not get a CEL this time, yay no misfires! (or so I thought). I remembered the car started to run poorly the first time when I was backing out of the garage so I gave it a couple quick taps on the throttle to see if it would start misfiring. It sounded it bit rough at times and had a bit of a hesitation but overall much better than the previous times. The AFR started to progressively lean out until it reached 18 at which point I shut the car off as it was obviously not able to correct the issue. I was a bit confused with the sensor names on the AP, I was expecting to see fuel trims but instead found A/F correction 1 / 3 / learning 1 etc. I assumed 1 and 3 refered to the front and rear 02 sensors and "correction" would probably be short term trims and "learning" long term trims? I'm still not completly sure about this but the data seemed to make sense. I attached the log to this post, I'm hoping I logged enough valuable info and the correct sensors. If anyone with a bit a knowledge could take a look at it and interpret what is going on I would be very grateful. From the very little I understand, the mixture started to lean out and the short trims start to rise to try and enrich the AFR back to stocheometric but the AFR didn't seem to respond. The values just diverge until the fuel trim is saturated at +25%. The fact that the fuel correction seems to not have any effect on the AFR is wierd to me. Could it be that the 02 sensor reading is wrong and the ECU is trying to correct for a bad reading? Or it is physically not able to send more fuel in the engine? Altought this seems less likely since I can get the engine to rev which would require more fuel than correcting mixture at idle. I could also be very wrong 2020-06-27 - Datalog.csv

You guys are awesome, I'm sort of getting an idea on how to start attacking the problem now. As Awfulwaffle suggested I started doing research on fuel trims and different sensor data and how to interpret them. I looked at a few hours worth of content on youtube by a channel called GoTech, pretty awesome stuff. Their videos are in depth, concrete examples and case studies on different cars and problems worth a good watch if someone reading this is in a similar situation. I'm pretty sure I have a small party smoke machine from when I was in high school, it's probably been 15 years since I've seen the thing but it must be laying around somewhere I guess I found a new purpose for it. So based on everything suggested here, here's my new plan : - Replace spark plugs (I got new ones, old ones were full of carbon and gap was at 0.060") might not be the problem but definitely won't hurt either. - Recheck coil pack connectors (I checked them last time, the clip on #3 is broken, I'll replace the tie rap holding it with a working connector from the spare harness) - Clean maf - Check for sensor values on coolant temp, intake ambient temp, as well as front 02 sensor I'm assuming I can check these values with the key "on" without the engine running? (02 I'm not sure about since it is meant to work when hot?) - Smoke test it to check for vaccuum leaks - Give it a start and data log the fuel trims, AFR, Target AFR, temps etc. Long term will be at 0 since I removed the battery but if the short term is still off more then 10% either positive or negative then something is still wrong. Depending on the results I'll probably have a better understanding of where to at. Here's where I'd love for someone with a bit more knowledge than me to shime in. The examples I've looked at on youtube are all for N/A cars. I understand a n/a car will always have a manifold pressure below atmosphere which means a vac or intake leak will make it run lean. I am right to assume at idle my car will behave the same since it is obviously not making boost? For a turbo car if I was to have a leak in the intake system (after turbo) my understanding is it would be running lean at idle and rich under boost since the system would be under positive relative pressure? And if it is a vac leak or intake leak before the turbo then it would be running lean regardless as it would on any n/a car? Also, how much time does it usually take for a car to start running clsoed loop? During open loop operation, it is my understanding that the 02 sensors are not taken in consideration. If so what data is used to adjust the trims during open loop, is it only running based off of maf, temps, rpms and fueling tables? If so then it basically doesn't have a clue of what is actually happening in the engine without the feedback from the 02 sensors so it can't be compensating for a problem occuring after the maf? Could it be I can't even reach closed loop operation, and if so are fuel trims in open loop even relevant? I know this is a crap ton of questions, I'm soaking up as much info as I can and trying to make sense of all of this. Once again thanks for shiming in, I'm enjoying the learning process.

I have not done any tests for vac leaks yet. I'm waiting on a vacuum gauge I ordered last week. As for ECU resets, I remove the battery between my visits to put it on a trickle charger since I get to go work on the car only once every other week. So what you're saying is I should worry about a mechanical issue since I get the problem even when starting cold and with the ECU freshly resetted? What kind of mechanical issue could cause this bad of a misfire? Timing? Although if timing was off it would'nt have run correctly the time I started it. I'm feeling kind of silly not to have tought about this earlier but what about bad fuel? With this covid thing I could not work on the car for a while and the fuel in there must be around 3-4 months old... I'll surely give the unplugged maf a try and clean it aswell.

+1 On the seized caliper. Happened to me also and the symptoms were very similar to what you are experiencing. If it ever happens again stop and check if you can feel heat radiating from one side in particular. There will most likely be heat emenating from all calipers but if one is seized it'll be obvious as it'll be quite hotter then the rest. The smell will also give it away.

Thanks for your input Redwagon. Actually it did run great until warm the first time I started it. Since then I can't get it to run for more than about 30 seconds, it'll run rough for a few seconds (maybe 10-15 seconds) then it gets worse and worse until it basically is only running on 1 cylinder and dies. I'll make sure de take a look at all of these. TGV's are deleted on my car if that is even relevant.

awfulwaffle thank you so much, I'll look into how to use the AP to get this data and post the results here. This is the kind of stuff I know I should learn, I guess this is a good opportunity. So if I understand correctly, I'll look at the AFR to make sure it's not way out of wack. If it is, then I look at the fuel trims to see if the ECU is maxing out it's ability to adjust the qty of fuel injected. Now say the short term trims are far from 0 I would guess it's because either it's getting a wrong read on the measured AFR thus trying to compensate for false data or it's physically not able to add or pull fuel in the cylinders which would indicate a problem with the fuel system? Am I understanding this correctly?

Thanks for your reply, I have a cobb AP to read codes and so far I got P0302 P0303 P0304 as well as PFFFF. I took the plugs out of cylinder 1 and 3 before I left last week and they were both wet with fuel so my guess is they all seem to misfire. I'll put new plugs in there anyway since the ones I pulled are covered in carbon residue. The car started to heavily smell like fuel when it started to misfire also...

Here's my story, I have been a silent reader of this forum for a few years now, it has always been very useful and filled with very knowledgeable people so thanks for all the help from the active members of this community. I would describe myself as a somewhat skilled parts changer. I've replaced engines, head gaskets, timing belts, done suspension work, brakes, fuel pumps etc. I feel confident in my wrenching skills, where I lack is with diagnostics. I've owned a 2006 LGT for two years, a year after I bought it I decided to do a leak down test on it since I felt it had a pretty bad piston slap. The numbers were horrible so I decided to look for a new (used) engine. I did check if I could simply rebuild it but the bores were already oversized and the machine shop told me they would not be able to get rid of the damage. Got a used engine from a reputable performance shop, leak down numbers on it were good so I went with it. Fast forward a few months the engine is now installed, I nervously turned the key and to my highest excitement and relief it fired right up and sounded waaayyy smoother than my previous engine. I let it run for 5 minutes or so to get it to temperature and burp the coolant system. Everything is still fine so I decide to take it for a short test drive, while backing out of the garage it starts to sputter a bit, than a bit more, until it basically sounds like it's running on only one cylinder and stalls. Now I can't get it to idle more than 20 or 30 seconds, same thing happens everytime. The car is in my father's garage, which is a two hour drive from my place so I try to make my trips worthwhile. Too many times I got there only to find out I'm missing a 2$ part and all the shops are closed because I can only get there on the weekends. I'm trying to make a plan of all the things I should be looking at to try and identify the issue. Here's what I'm thinking : 1. Check the spark plugs / Coils / Wires 2. Replace the 02 sensor with the spare one from the previous engine 3. Compression test all cylinders to make sure the engine is healthy 3. Clean Maf sensor? From here I'm kind of clueless... To be honest I don't really know where to start looking, I don't want to blindly throw parts at the problem I'm looking to sell the car soon I just want to make sure it is in good working condition. I would love to hear your theories on this and what you guys would recommend I look for. My guess is it's probably not mechanical since it ran just fine for a while. Maybe the plugs or coils but why would all of them start to fail at the very same time, seems pretty unlikely. At first I thought it might be related to the 02 sensor since it started to misfire only when the car got up to temp but I've tried starting the car up again when cold a week later and it ran like crap instantly and stalled after a few seconds. Anyway any input would be greatly appreciated, sorry for the long post, cheers from Canada!