poonpower

Hey guys, long time since the last post, because I've always been able to find answers now that these cars are fairly established. But I'm having a problem that I just cannot figure out, nor my remote tuners. So I'm here looking for second opinions, kinda like when you want a second opinion when you fall seriously ill.

Problem: Car was flashed with the suggested scaling and latency else where on this forum. Cold starts it starts right up, hovers around 2000rpm, then slowly drops to ~1200 as the temps rise, but eventually after 30+ mins of idling it'll want to stall out unless I give her throttle. It's always rich, around 10s to 12s afr, even when I blip it. Then when I blip it, it'll rev pretty freely, but on the way down it will begin to die and not catch itself. On hot starts i need to give it around 20% or more throttle to start barely, but same thing would happen as above, no matter the percentage of throttle 30-80% it would still die. None of my fuel trims work, but with it being a evo 5 ECU it'll only log STFT anyways.

Specs:
Evo 4 with Evo 5 ECU with Ceddymod,
156mm long rods
Manley long rod pistons at 9:1 CR
GSC S2 cams
FIC 1050 injectors
Walbro 255
FP Red

What's been done. The engine is completely rebuilt, zero miles on it. Timing was triple checked before any accessories even went on. Cam and crank trigger plates double checked. Cam sensor replaced. TPS replaced and set at 0.63v closed and 4.9v open. ISCV replaced and works. Tested for vac and boost leaks twice, holds very well. MAF was cleaned. Front O2 replaced. Scaling and latencies have been played with a lot by tuner, and he suggested that the FPR may be failing as its always rich, and it IS 22 years old.

My next step is to install and configure the AFPR, but I am at a total lost what else it could be. Ceddymods do not have as much features as TephraV7. But if I was going to change ECU, I might as well go ECMLink or even a Link G4. Money is definitely an issue, so I want to try to nail down the problem first.

I can provide the ROM and logs if needed.

Thanks peeps

jozy

you have already mentioned your problem - rich

if you can fix that and get your afrs in the correct figures then i think you can have less to troubleshoot

what do you mean suggested latency and scaling? do you mean for injectors?

poonpower

I'm installing an afpr to see if that solves the issue. And the scaling and latency values were attained from another thread on this site. These injectors are very well documented haha.

Does this also sound like a ISC problem as well? I tested it, but I don't know if it ACTUALLY goes in and out.

jozy

Yes I think fuel pressure at idle (no vacuum hose connected) should be 3 bar (43.5 PSI)

do you still have your original injectors? put them back as an attempt to troubleshoot and of course remember to update the injector settings (remember e4 injectors are smaller than e5)
see if it gets better then at least you know what is causing the issue.

i assume you also have a VTA BOV which will accentuate the stalling issue.

i am also vta bov running ceddymods on my evo 5 with maf. i made the reving up and letting it fall and stalling better by increasing the iscv steps.
i guess with your big injectors you get it worse.

poonpower

Update:
Installed the afpr, set at around 43psi (dial gauge, increments of 2psi). No change in idle or throttle behavior, it seemed to idle a bit leaner for the short amount of time that it idled for though. I also messed around with the ISCV, decided to remove the whole FIAV/ISCV housing from the throttle body to see whats up. Cleaned it all and made sure the ISCV plunger is actually moving in and out. It wasn't before so I cleaned it and swapped in another one that I had on hand. Buttttt the gasket to that housing has swollen up and wouldn't go back in, so I now have to wait for parts from Japan so I can install it properly. Such a pain in the ***.

I've already tried the e4 injectors with it's scaling and latency, no change in behavior.
Im not running a VTA, just the stock evox metal DV.
What did you change for the ISC parameters in Ceddy? Ceddy has very limited functions compared toe Tephra, so some of the things I read here don't apply in Ceddy.

Thanks for the help. (Also a fellow Hong Kong'er)

jozy

yes this is mostly a us based forum so mostly only ct9a information on here

i changed the tables for "iscv position - ac off neutral" and "iscv position - ac on neutral" basically increased the values for the last 2 rows which is for higher engine(coolant) temp

mostly i think stalling is because of rich condition and not managing to spark ie. iscv not giving enough air to the amount of fuel injected
that's why vta bovs (except hks ssqv) has this stalling issue too

haha you're hker in canada and i'm singaporean in hong kong

poonpower

What rom are you on?? My Ecuflash do not have those tables. I just have two tables: ISC vs coolant temp, and desired RPM and coolant temp ( I think)

I'm on the ralliart ROM with ceddymod. Mind if you send me your ROM??

400s

Post a log from dead cold to fully warm here with a pic of your injector size, injector deadtime, Desired Idle RPM and Desired ISC Initial Position tables here.

foxbat

What type of o2 sensor are you using, 2-wire or 4-wire?
It might be a bad MAF, I suggest either trying a different MAF or converting to SD & see how it goes.