Cold engine start surge and cutoff? I have been looking for a answer for what could cause this on a completely stock engine with all scanmaster readings correct. I have heared of going with a ls1-lt1 maf and translator will fix the issue and that a modern tt chip and injectors can fix it. I am trying to keep the car all stock but not sure in which way to go to fix this and what causes this? Tried three diffrent known good stock MAF's new IAC,new TPS. Reset IAC,TPS. IAC counts at warm idle 25. TPS .42-4.50.
Cold engine start surge?
- Thread starter viokrome
- Start date
Those are all the mods done to car, all original except the mods listed and a fuel pressure gauge on the fuel rail, gaskets and seals!
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GNONYX
Well-Known Member
- Joined
- Oct 16, 2009
You still need to give the Scanmaster #'s
What's the mileage?
Did you use MAF sensor cleaner, IAC, and inside throttle?
O.K. here are the numbers! I was lucky to have a local TR guy ride along with me to check it out. The car cold started and ran fine at idle start-up for the first time I cant explain it? I took it easy at first to check the rear main seal, all good no leaks! But when I did a few WOT runs my scanmaster numbers were not good, the recall was 843 mv 5.6 kr that scared me! why so much knock when o2 shows not lean? The guy I had with me said I have the wrong vac hose on my boost line and it was making over 15lbs of boost on the stock boost guage i am including a pic of the boost line from the solenoid to the wastegate actuator. Thanks for any input! Sorry so long but this is the only way I could explain it. Car has 43861 miles, used 02 safe throttle body claner on maf,iac and throttle body.
with car off key on tps .40 wot 4.44
740 00
af 05
lb 40
bat 13.6
int 126
bl 142
nph 00
clt 181
ats 102
r 750
tps .42
iac 28
cc 1 then 9 counting up
nal oo
with car off key on tps .40 wot 4.44
740 00
af 05
lb 40
bat 13.6
int 126
bl 142
nph 00
clt 181
ats 102
r 750
tps .42
iac 28
cc 1 then 9 counting up
nal oo
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GNONYX
Well-Known Member
- Joined
- Oct 16, 2009
BLM is just a little high, I believe there is a threshold level of +/-10 of 128 which could be vacuum, exhaust leak, or fuel.
You might want to check if any metal or exhaust pipe is touching which may cause the kr.
I saw your inserted picture, it looks ok, but is that the original hose or did you replace the hose with a larger size?
Do you have a fit or adjustable wastegate actuator
Here is a photo of the wastegate hose connection.
Original wastegate actuator. The previous owner insalled the hose. I think I might have a vac leak at the throttle body to plenum will check again.Going to install a after market boost gauge. Will double check the exhaust for anything touching but I dont think so. Thanks...
After looking around I found that if i shaked the exhaust that the l/h tail pipe was hitting the gas tank with not much effort, so I adjusted it now it does not hit. Also was told to roll into third gear and check readings that shifting hard could cause false knock. I will drive it and report back what I find. Thanks again GNONYX!
I think I finally found the problem! I was told the car had a stock ecm chip but after further inspection I found a hypertech 41372 Installed.
From what I have been reading this could be what is causing all my problems, cold start surge, rough idle,over boost and detnation at wot.
Still dont know how I could have 843 mv-5.6 at WOT. Goning to order a TT chip from eric. Let me know what you guys think!
From what I have been reading this could be what is causing all my problems, cold start surge, rough idle,over boost and detnation at wot.
Still dont know how I could have 843 mv-5.6 at WOT. Goning to order a TT chip from eric. Let me know what you guys think!
GNONYX
Well-Known Member
- Joined
- Oct 16, 2009
Glad to hear you found the problem. Is the replacement chip being size with the stock injectors or are you going to get the bigger injectors if so what size were you told? You might need an adjustable fuel regulator, and a hot wire kit. You can still keep the original MAF if you don't have a problem with it. According with the Scanmaster your AF is 05, that's good
http://www.racetronix.biz/customkititems.asp?kc=RFPK-006&eq=
http://www.turbotweakstore.com/ProductDetails.asp?ProductCode=1009
I have an email in to eric waiting to hear back so I can figure out what chip injector combo to run, the lowest chip injector combo the have listed is for 42 lb. injectors. Any suggestions would be great!
Thanks.
GNONYX
Well-Known Member
- Joined
- Oct 16, 2009
That's a hard question since each member has their own personal and goal to set up the TR.
You claimed you want to keep it stock and yet there are many TR that looks stock, but running in the 10-11 sec.
You know it all depends what you want to do. When I started to learn about the TR, I didn't even know which way to go or to choice from. A few members claimed go with 60# injectors, so if you ever wanted to upgrade you'll have the fuel system cover.
I think the 42# is a good choice and it's above the stock injectors, keeping it close stock. The good part is least you can tune the engine better than using factory stock components.
This is only what i did, but you asked for opinions. I bought matching 60's and chip combo. Runs great. Maintains stock appearance until somebody runs the numbers on your injectors!! If you ever decide to up the power, you'll have the injectors to do it.
Just had the driver side header welded and pressure tested,also checked the r/h header also it was good, the stock boost guage is close checked it against a after market one and it was close. Going to install a autometer pro comp boost guage next week to be sure. From what I have read the hypertech chip is old and was discontinued becuase of some of the same problems I have.
GNONYX
Well-Known Member
- Joined
- Oct 16, 2009
I agree, I had a hypertech chip years ago, little did I known, it kept burning out the GM stock o2 sensor and I finally got rid of that put back the stock chip until I got a Full Throttle chip.
