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I installed a 10 gauge wire to the fuel pump today started it up and my idle pressure was at 62 like before but this is cold.
At 35 F, I maintained under 13.2 in the 4-5k rpm range that was lean before. It's perfect everywhere else. This is with the same rrfpr setting.
When I got home, my fuel pressure was 76psi with vac connected and 88psi with vac disconnected! Crazy how the car felt perfectly fine but my pressures are so high. The fuel pump rewire definitely had an effect on the car.
Edit* - this morning the car is reading 10psi fuel pressure with car turned off and cold. Is this normal or is my gauge defective?
I found out the gauge I installed broke. It is showing 12 psi when I took it off the car so the high pressures showing last week was not accurate. Is it pretty common for these gauges to be defective? What brand should I buy?
Today I installed the stock exhaust back on and it made the car a bit richer. Still struggling in that 4-5k rpm range though.
S2000Junky I've been reading a ton of old threads on the basic ctsc kit and sos and you are in most of them lol.
So today I found out that my vtec is perfectly normal at 6200rpm with belt disconnected and fvm disconnected.
I then connected the fvm with no but and saw that vtec is still at 6200rpm and no hiccup.
I did not back my fuel pressure any. This means the fvm module somehow senses boost and only lowers vtec when there is boost. And this hiccup happens.
I don't know if it's normal or not maybe people don't even notice the hiccup since it's kind of subtle. It can be clearly seen with a vtec indicator light though.
S2000Junky I've been reading a ton of old threads on the basic ctsc kit and sos and you are in most of them lol.
So today I found out that my vtec is perfectly normal at 6200rpm with belt disconnected and fvm disconnected.
I then connected the fvm with no but and saw that vtec is still at 6200rpm and no hiccup.
I did not back my fuel pressure any. This means the fvm module somehow senses boost and only lowers vtec when there is boost. And this hiccup happens.
I don't know if it's normal or not maybe people don't even notice the hiccup since it's kind of subtle. It can be clearly seen with a vtec indicator light though.
Yes ive been around a wile lol Ive had my fair share of problems to figure out too.
-Normal isn't 6200rpm, its 5900rpm. You may have an OEM issue there.
Doesn't make sense to me that the FVM would only alter vtec if it "senses boost", possible it may have been programmed that way, but it seems like added processing/programming that isn't required. 4200rpm was the engagement point of the FVM from what ive gathered through others running this system. Unfortunately I don't have first hand experience on that one to confirm for you. I would contact the guy who manufactures these FVM units for SOS/CT-Engineering and talk to him about what your experiencing, and ask him to verify some of these tuning parameters in the unit to see if you can get to the bottom of it, since SOS or CT isn't much help here.
**Make sure your spark plug gap is somewhere between 0.25-0.30 to remove spark blow out as the cause of your hiccup symptom.
**** Also the FVM could be totally fine, but the MAP clamp feature voltage isn't set right, and may be freaking out the ecu momentarily when you start to make positive pressure, before the unit is able to compensate for that. If your running a smaller then stock pulley, I wonder if your boost is coming on before the unit was calibrated for. This could be a simple reprogramming/adjustment. Just another question to ask/consider. 2.85v is where the MAP should be clamped I do believe. It may be beneficial to go lower like 2.80-2.75v even without detriment. I had to do this on my E manage ultimate to get proper performance.
Last edited by s2000Junky; 01-23-2017 at 10:03 AM.
Yes ive been around a wile lol Ive had my fair share of problems to figure out too.
-Normal isn't 6200rpm, its 5900rpm. You may have an OEM issue there.
Doesn't make sense to me that the FVM would only alter vtec if it "senses boost", possible it may have been programmed that way, but it seems like added processing/programming that isn't required. 4200rpm was the engagement point of the FVM from what ive gathered through others running this system. Unfortunately I don't have first hand experience on that one to confirm for you. I would contact the guy who manufactures these FVM units for SOS/CT-Engineering and talk to him about what your experiencing, and ask him to verify some of these tuning parameters in the unit to see if you can get to the bottom of it, since SOS or CT isn't much help here.
**Make sure your spark plug gap is somewhere between 0.25-0.30 to remove spark blow out as the cause of your hiccup symptom.
**** Also the FVM could be totally fine, but the MAP clamp feature voltage isn't set right, and may be freaking out the ecu momentarily when you start to make positive pressure, before the unit is able to compensate for that. If your running a smaller then stock pulley, I wonder if your boost is coming on before the unit was calibrated for. This could be a simple reprogramming/adjustment. Just another question to ask/consider. 2.85v is where the MAP should be clamped I do believe. It may be beneficial to go lower like 2.80-2.75v even without detriment. I had to do this on my E manage ultimate to get proper performance.
I emailed SOS and they confirmed that the FVM will only engage in boost and VTEC should be at 4800 rpm. But ive read a thread on here that claims the vtec is affected by altitude too so that may explain my late VTEC. (Im at 1 mile altitude).
Also they brought up that it may be a low pressure issue. Since the oil pressure is lower at lower rpms, there may not be enough pressure to activate vtec at the lowered rpms. I will inspect the vtec screens and solenoid as you've suggested but it wont be till a while because i need a second hand to get that supercharger off! I wonder if my vtec oil pressure switch is bad as well.
The gap and plugs I am using is recommended based on the SOS website because I assume my car is below 375 bhp where they would switch over to the no. 8 heat range. I will take down the gap to .030" to see if it helps.
I don't think it is the pulley because i had this issue with the stock pulley a well. Ive also read the thread with the guy who makes the FVM so i may contact him to see if he could help out. Thanks yall!
The whole 5800 VTEC (stock) and u saying 6200....If ur looking at ur rpm gauge it is not always the most accurate. I have read them to be as much as 500 off. U have to verify what ever is on the ECU or what ever is altering the signal.
Higher altitude will effect vtec engagement point, not the first ive heard of this from other members. Didn't know the OP was at 1 mile elevation. I'm at sea level myself.
Higher altitude will effect vtec engagement point, not the first ive heard of this from other members. Didn't know the OP was at 1 mile elevation. I'm at sea level myself.
Do you happen to have the contact info for the guy who supplies Acm and fvm modules? I saw it in a thread somewhere but couldn't find it again.
Well I changed the gap to .030 but still getting the vtec hiccup.
I spoke with shad from driving ambitions and he's a real nice guy. He said it was like 5 years ago since he supplied fvm to sos so they probably changed the tune since then. He does not think it's an oil pressure issue but maybe since the fvm was tested in Arizona it may not work correctly at 1 mile high. One challenge he had with the fvm was u can't lower the vtec too low or it will throw a CEL. Since he can not download the map from the fvm, it would be difficult to change anything on the without being on location. The fvm can actually be tuned on a 100 rpm resolution. Other forum members have gotten custom tunes in the past but SOS will no longer offer anything other than their original map from my experience.
I'll just live with the vtec hiccup. Before I installed the light I thought it was boost kicking in lol. Its not too bad because it's not a hesitation, but more of like small bursts of power before vtec finally locks on.
My af ratios are pretty good at 62psi fuel pressure (vac connected). I jump to 13.2 for a bit during 4-5k but the car only has ~1psi at this area. Shad told me I shouldnt be worried since it's such low boost.
Thank you for all the help guys. I will go for ems when my clutch dies out and I upgrade clutch but for now I'm happy with the performance I've gotten. Hopefully this thread will be useful info for those who are looking at buying the SOS stage 1.
01-14-2017, 06:17 PM
