Car keeps killing!!!!!

[VTEC8YA]

So this is the second time that this has happened. Im cruising down 52 last night and decided it looked like a good time to mash it to the floor. I ran it to the end of 5th gear, pushed the clutch in to coast and *puke*, the damn thing just kills. Ive noticed it doing this when im on the highway and I hammer on it. If i just put it in neutral and coast the rpms seem to drop very low... probably like 200 or so... then just start bounching around between 200 to 600 rpm, rather violently too. It doesnt do this when im just driving in the city. Only right after I go WOT on the highway and then put the clutch in to coast. Its not like this happens fast enough that I dont have time to put it in the next gear. Its very strange. Now I know I can just put it in 6th and I wont have that problem... but its just the fact that I know this happens if I dont. Driving me crazy. Any ideas? Thanks for any help.

 

[dmention7]

mods?

Also, why do you put the car in neutral to coast on the freeway?

 

[dmention7]

As a side note, the title of this thread had me picturing something far more interesting.... =/

 

[VTEC8YA]

Wow! Nice. Why would I? Well the first time it happend I was just creeping up on a slow moving car after WOT and so I threw it in neutral and the thing killed. Then last night I recalled asking Tom if he ever experienced anything like it, so I tried it on the way home and it happened again. Pissing me off.

Mods: Cobb SRI, Forge BPV, CoBB Ap Stage 1+sf 91

 

[VTEC8YA]

What is that picture from?

 

[dmention7]

Heh, the pic is from the movie Christine... based on a Stephen King book about a car that kills people


Also, I was just curious why you'd pop the car in neutral on the freeway... never really heard of anyone doing that apart from hypermilers.

Does it do it anytime other than after a highway pull? If you WOT rev it in neutral then let off, does it return to normal idle, or does it die then too?

 

[VTEC8YA]

Only WOT. City streets too. Say if I were to go stop light to stoplight and be on it, if I put it in neutral as im coasting to a stop, it will do it. I know its not normal driving habit, but its just I experienced it that one time so it bothers me.

 

[dmention7]

Any pops or backfires between shifts? What you're describing is exactly what happens when people run VTA instead of recirculating without proper tuning... the engine goes pig rich after a shift and often bogs out and dies.

 

[VTEC8YA]

nope.. never a pop or bacfire. I am running the Forge bpv so obviously recirc.

 

[dmention7]

I'd run some datalogs on your AP then, and see if anything there clues you in... AFRs going rich instead of lean when you get off the gas, fuel pressure dropping like crazy...

 

[VTEC8YA]

Roger that. i will do that this evening and post.

 

[DrWebster]

Only thing I can think of is that your rev limiter is being a little bitch.

Jay asked a good question; if the car is in neutral already and you open it up to WOT then let off, does it stall? What about car in neutral with the clutch out, you go WOT then get on the clutch? I'm curious if the problem is related to the car being in gear or in motion vs. it being something just related to engaging the clutch at WOT.

 

[VTEC8YA]

I mean even if im in 5th and I put it to the floor, then say get on an off ramp and dump it in neutral, it will almost stall. RPMs will just dance all over. I dont have to run it to red line, just get some boost built up.

 

[dmention7]

Well, my guess is that it's an issue with fuel metering when the BPV opens up under boost.

 

[VTEC8YA]

So like its not delievering the fuel it should be? Im not gonna lie... I dont know JACK about turbo's. In my past life I was a honda fan boi.

 

[dmention7]

Fuck, I had a long post written out, but the forum ate it...

Anyways, I don't mean that it's a problem with fuel being delivered, it's a problem with the car deciding how much fuel to be delivered based on readings from the MAFS.

 

[VTEC8YA]

Alright, heres a log. You can see around 26 seconds where things start to get a little hairy with the rpms. Not sure if this is normal or not, Also saw some detonation at high rpm, 3.85!!

Never mind, that didnt work, Any idea how to get a .csv file to upload here?

 

[VTEC8YA]

K, heres a log. Look at around 26 seconds. Thats when I let off and put it in neutral and coasted.