lt1formula2000

iTrader: (10)

I've been driving my car with the MS4 in it for about 2 weeks now. I had my PCM mail order tuned by TSP and the car has been fine since the first up except the last few days it has been having some idle issues everything from a hanging idle while rolling to bouncing from 500 to 1500 at a stop with the AC on only a little more stable with it off. Also in the last few days sometimes when I get on it and grab second hard if it spins up to the limiter/or close the SERVICE VEHICLE light will come on. Once you kill the car it doesn't come back until I run the car real hard again. The SES does not come on during any of this. Today it drove to work 100% when I went to go to lunch I hit the key it immedialty started up but died in 2 secs(no struggle just straight died) so I started it again and this time it idled at 2100 and stayed for 45-60 secs then idled down like normal but it wouldn't hold a idle hardly at all with the AC on. So I took it home on the way it had some part throttle stumble(never heard any distinct misses, no SES light) ran it up to 5000 in 1st and 2nd(80-90% throttle) a time or two and it's fine but it does feel it has lost a good bit of power smoothness(as compared to last week) at low RPM low throttle. I was thinking maybe it the TPS, I ruled out IAC since the it seems to have trouble not only at idle. But no codes have set the SES light off. I have no idea what sensors the SERVICE VEHICLE light is hooked up to. I've never seen that light before. I also just recently put a 160 thermostat so I guess tonight I'll switch that back and clean the IAC and check the TPS voltage.

Sorry for the long post just trying describe whats happening. I would appreciate any help.

Anybody know what might activate the service vehicle light.

jmm98LS1

iTrader: (28)

A flashing SES light could possibly be a misfire, so the threshold might need changed. Without scanning/logging capabilities it's hard to tell what's happening. IMO the MS4 is too big of a cam to expect to run well on a mail order tune. Every car, even with similar mods, is different and will behave differently especially while idling. I would look for someone in your area with tuning software that can touch up the driveability on your TSP tune, or possibly look into purchasing your own software. It's not hard to do if you're willing to read and learn.

lt1formula2000

iTrader: (10)

No flashing SES(random misfire) it doesn't seem to be missfiring, I wonder will a O2 switching problem set the SES off. I think I'm going to get some Bosch 13111's I ordered HP tuners, when I said it runs ruff, irractic idle and a lack in low end power I mean realative to the cam. In the last few days it has started running drastically different then it did for the first week or so that I drove it with the cam in it. Basically I was just wondering about the serevice vehicle light I don't know what sensors would set it off. My car is a TCS car but I have a 3 channel axle in, so it can't be sensing the rear wheel speed sensor to tell wheelspin. I ignore the light for now, I'm just wonder what it could be on for. I thinking maybe the 160 is keeping it cool enough that the PCM is keeping the motor a little rich. And the car actually runs much better then I ever expected it to on a mail order tune.

WhiteRhino

iTrader: (6)

There is no way to guess. There's to many reasons that the light could be on for. Somehow try to get it scanned.

The biggest problem with that cam, is you mail order tuned it. Imho it will never be right, no matter what your butt-o-meter says. If you have no access to tuning/scanning software you could post up in the regional section for your area and see if anyone would help you out. I know alot of people have no reasonable access to tuning their cars and might have to travel. I would never touch my car without having some sort of abililty to get it tuned properly. I don't think it will ever idle right without some hands on tuning.

Best of luck!

lt1formula2000

iTrader: (10)

rino did you see post #3?

I ordered HP tuners, and actually you would be surprised at how well the car ran with the TSP tune. When I took it to the paint shop they couldn't believe it ran like it did with that size cam. My tach is also starting to act up and it does it at the same time the motor starts running bad I guess the crank position sencsor or cam sensor which ever one the the PCM monitors for motor RPM. After work my friend is bringing his scanner over so that we can check.

As far as tuning I plan to tune it fully, but until now it had been running so good it only needed a few tweeks to elminate so surge at low RPM, And check the A:FR maybe a little change there we pulled the plugs and they all looked good, tad bit richer then ideal I guess by the look of them.

WhiteRhino

iTrader: (6)

Somehow I missed it.

Since you do have Hp tuners coming, just try to stick it out untill you have it. Or untill you can get it scanned. It is very hard to guess at what sensors are giving you a hard time. Check for loose wires as well. A loose ground could give a problem as well.

A long time ago my ses would come on during wot. It was a maf code. One of my zip ties broke and the o2 wire touched the header, shorting it out. When I went wot I guess it was enough to raise the header to come in contact with the hanging wire.

Anywho, good luck and I hope you get it figured out!

2000badbird

iTrader: (5)

a flashing ses lamp means that damage is bein done to the cat converter or the pcm thinks that is whats happening even if u dont have them. knock sensors measure the amout of vibration of the engine and determine if it is missing. the amount of vibration of a large cam can cause the knock sensors to read a miss even if its not

LS1IMPULSE

iTrader: (42)

Hey any update on your car? Ive got a Trex in mine and I am having some of the same problems as you are. Mine will start and idle fine (the guy i bought i from said he tuned it for cruising with HPtuners, which the car came with) and it will run ok up to around 3500-4K RPM's (not utned for WOT so i havnt got above) but around 2500 it will misfire and throw the p0300 code, and it does misfire becuase it bucks pretty violently and also about 3500 it i start to get on it it will do it agian (maybe because of not bei ng tuned) but now the low oil light pops on momentarily when i misfires along with the SES light?