The Project Pad

it seems like my car is going into flood clear mode when running and i hit 100% throttle. any idea what could be causing this now? i recently installed a bosch 044 fuel pump to replace the tired old one that was on there but other than that i didnt touch anything else. i attached a vemslog so you can see what its doing, sometimes it will push through but most of the time it wont and under a pull the car just shut off when WOT is applied.

Haven't looked at the log yet, but that sounds like boost cut.

your tps signal looks fubar. unless you were slamming the throttle open and closed very rapidly it looks like the signal is cutting out. when it does this, the ecu i entering decel mode and shutting off the injectors.

it seems to be getting worse as the car wont even barely start now. i have to hold it at half throttle and run it on the starter to get it to start and than hold it at 60% throttle to get it to idle and than at random it will just shut off without any warning. i wasnt mashing the throttle at all in that log, that was just simply holding it at wide open throttle and it does that.

i had the coupe GT digital dash wired into the car for the past few years but like last winter the coolant/fuel gauge side of it started acting up and wouldnt display so now im in the process of reverting the car back to its original analog cluster. this whole problem started before the cluster swap though but i though if the cluster was shorting out internally it might be pissing VEMS off. i tried to start it with no cluster in the car at all and no change. this is just my luck too, i recently earned some free dyno time at a local shop and the car goes down the shitter again when im just getting ready to tune it properly.

Trigger signal? I've had funky ass shit happen with a bad trigger signal. Like die at whatever RPM, much like a overboost fuel cut.

vwnut8392 wrote:it seems to be getting worse as the car wont even barely start now. i have to hold it at half throttle and run it on the starter to get it to start and than hold it at 60% throttle to get it to idle and than at random it will just shut off without any warning. i wasnt mashing the throttle at all in that log, that was just simply holding it at wide open throttle and it does that.

check your wiring.

its not magic. if the signal is showing 0 to 100% oscillating like that its a wiring or sensor issue. similarly if the ecu thinks your throttle goes to 100% while cranking it will enter flood clear mode and shut off the injectors.

Seems pretty cut and dry to me after Marc saw the tps problem.

i've been messing with it still all weekend and i finally got it to show random trigger errors. here's a few VEMS logs from it showing the trigger errors. the battery level is low at first because i took out the digital coupe GT cluster and switched back to an original analog cluster so you have to rev it a little to get the alternator to start charging. i went over the harness and everything seems in order so i rule out a wiring problem. i added 3 vemslogs from tonight so you guys can see what its doing now. FYI im running on all OEM crank and cam sensors now, i ditched the custom 60-2 crank setup a while back.

fix the tps.

its possible you may also have some trigger errors as well. you wont be able to use .triggerlogs to find them at high rpm. seeing as it happens mostly with launch control its probably misfire related more than actual trigger related.

Marc wrote:fix the tps.

so you think the TPS sensor is bad?

He's saying that based on the log data, the TPS *signal* looks bad. That could be due to a bad sensor, wiring, or even a problem inside the ECU (rare).

elaw wrote:He's saying that based on the log data, the TPS *signal* looks bad. That could be due to a bad sensor, wiring, or even a problem inside the ECU (rare).

well i guess i'll start with changing the TPS sensor. i wonder if there's an interchange from something else besides another AAN/3B throttle body because i only have 2 and one is the suspected bad one and the other is on my daily driver S6.

swapped TPS sensor from my S6 to the 4000 and no change plus the S6 runs fine still. check wiring with a multimeter and all checks out. one thing i did find was an engine ground that wasnt hooked up so i fixed that and it didnt make a difference either. im starting to point fingers at the crank sensors because i took a few trigger logs and there's some wonky stuff going on when i rev the engine. here's a few of the trigger logs now so you can tell me if it looks normal or not. there's a really strange dip when i rev the engine, it doesnt make sense to me.

well i swapped the crank sensor with my other car and the signal is cleaner but it still does the same thing and the S6 runs fine on the supposed bad sensors so im puzzled.

im going to take fuel pump control from the VEMS ECU and just make it simple so that it turns on with the key and turns off with the key. i feel its something in the ECU shutting the fuel pump relay down now.

vwnut8392 wrote:im going to take fuel pump control from the VEMS ECU and just make it simple so that it turns on with the key and turns off with the key. i feel its something in the ECU shutting the fuel pump relay down now.

waste of your time.

the ecu stops seeing triggers so it shuts off the pump. its a symptom of a different problem. we can see the problems in your log, work forward until the logs look perfect.

i took control of it away and the car acts perfectly normal now, not a hiccup blip or anything. i would still like to correct it and make it work properly but its definitely the ECU shutting everything down. here's a vemslog without the ECU running the fuel pump. im not sure what a perfect log is supposed to look like for the AAN.

your problems are mostly hapening at high rpm. the baud rate of the trigger log wont record properly above about 2500 rpm so this log doesn't really tell us anything.

a fuel pump relay cant possibly cause trigger error and or fluctating tps readings in your datalog.

Marc wrote:your problems are mostly hapening at high rpm. the baud rate of the trigger log wont record properly above about 2500 rpm so this log doesn't really tell us anything.

a fuel pump relay cant possibly cause trigger error and or fluctating tps readings in your datalog.

what i meant was that something is making the ECU unhappy and thats making the ECU shut down the fuel pump, injectors etc.

i did read a thread on the vems support forums where a guy had a similar problem where it evenually lead to the VEMS ECU not turning on the pump at all and he switched the output to a different pin in the ECU connector and the problem was solved. have you ever seen something like this before? i'd be willing to atleast try it because i feel my triggers are completely fine as im now running the car on the fairly new crank sensors that are only a few years old from my S6 and my S6 is running just fine on my old sensors from my 4000 that are original to the AAN from 1993. my cam sensor is only a couple years old on my 4000 too.

well i tested the TPS sensor and it comes up within spec as per the bentley manual, changed the crank sensors again, put a brand new cam sensor on it, i removed the whole entire engine harness, went over it with a multimeter and reinstalled it back into the car. only thing i found in the harness that i thought may be causing it was that a wire on the 135 tooth crank sensor was slightly broken so i repaired that. over all nothing has cured the issue. one thing i did notice is that when the car was running the N75 valve was tweaking out and pulsating which isnt normal at idle so i unplugged it and still no love. i dont know what to do with it at this point as its so random that i cant pin point anything in specific thats causing it. the car sat and idled fine for 15 minutes, would rev, could drive and than boom it just shut off. than other times it will start and i can barely rev it and it shuts back off.

Here is a link to my VEMS folder on my google drive. instead of saving to just one computer i save to my google drive so i have access to everything on any computer. this can and will update every time i mess with the car. so please dig through everything and view all the logs and tunes i have for my car and maybe just maybe you guys will see something i missed.
https://drive.google.com/folderview?id= ... sp=sharing

this is about how i feel right now.

Lol

That is messed. Dunno what to tell you, I had weird issues as well that was finally diagnosed as a missing ground to the ECU. The pin was just not there in the ECU connector so VEMS was expecting a ground in that pin but it was somewhere else. So messed up.

But I've never had random shutoffs like that. But falling flat on its face sounds like a primary trigger gap problem.

Oh. What plugs are you running and where are your coils? When I ran non-resistored plugs the car would shut down after a full throttle to redline pull. As soon as I lifted and shifted it would just die. Took me a while to realize that problem. My coils were right on top of the ECU, only separated by the thin body. Yay harmonics.

chaloux wrote:Lol

That is messed. Dunno what to tell you, I had weird issues as well that was finally diagnosed as a missing ground to the ECU. The pin was just not there in the ECU connector so VEMS was expecting a ground in that pin but it was somewhere else. So messed up.

But I've never had random shutoffs like that. But falling flat on its face sounds like a primary trigger gap problem.

Oh. What plugs are you running and where are your coils? When I ran non-resistored plugs the car would shut down after a full throttle to redline pull. As soon as I lifted and shifted it would just die. Took me a while to realize that problem. My coils were right on top of the ECU, only separated by the thin body. Yay harmonics.

Im running NGK BKR7EIX plugs and 07K coils. marc mentioned timing gap on facebook and i wonder if my timing belt is stretched or worn out enough to mess with it? but the thing is it will do it randomly at idle or at high rpm and thats what makes it so puzzling. i noticed my vacuum line to the MAP sensor was sucking shut at idle so i redid every inch of vacuum line in the whole car including everything to the diff lock controls and diff locks with parker parflex 98 durometer polyurethane tubing. its a bit over kill but it wont ever mess up or get soft like rubber line.