Porsche 911 LS1 Swap need Help!!
09-26-2009, 05:21 PM
#1
Porsche 911 LS1 Swap need Help!! My LS1 911 conversion is getting very close to being finished but I have a problems with the timing or PCM programming.Car starts up and idles around 800rpm's, I am unable to rev past 1500rpm and gas fumes smell extremely rich. Below is some history and what I have done so far
BTW, Have used the scanner and get the following codes:
P0121 TPS/Pedal Position
P0336 Crankshaft Position (this is where I think the problem is but I changed the sensor and still same problem
P0481 Cooling Fan 2 control ( I have output wire to relay)
Here is the history:
- Techrod standalone harness
- 99 Camaro Engine
- PCM programmed with VAT's and rear O2's removed
- Returnless fuel rail with 50 PSI of fuel
- Coil packs from 2008 vette
- Typhoon Intake
- 85mm SLP Mass Flow Sensor
- 85mm throttle body
- Changed plugs
- drained gas and filled with fresh tank
- Replaced Crankshaft Sensor
Appreciate anyones help from this forums, I am new to the LS1 world but learning quick
Thanks
BTW, Have used the scanner and get the following codes:
P0121 TPS/Pedal Position
P0336 Crankshaft Position (this is where I think the problem is but I changed the sensor and still same problem
P0481 Cooling Fan 2 control ( I have output wire to relay)
Here is the history:
- Techrod standalone harness
- 99 Camaro Engine
- PCM programmed with VAT's and rear O2's removed
- Returnless fuel rail with 50 PSI of fuel
- Coil packs from 2008 vette
- Typhoon Intake
- 85mm SLP Mass Flow Sensor
- 85mm throttle body
- Changed plugs
- drained gas and filled with fresh tank
- Replaced Crankshaft Sensor
Appreciate anyones help from this forums, I am new to the LS1 world but learning quick
Thanks
09-26-2009, 08:03 PM
#3
On The Tree
iTrader: (1)
Join Date: Mar 2006
Location: Phoenix, AZ
Posts: 174
Likes: 0
Received 0 Likes
on
0 Posts
This is a bit of a long shot, but I seem to remember that you can reverse two of the sensor connectors on an LS1. There was a guy putting one in a 240SX recently on this forum that did just that. You might want to resurrect his post.
I don't like scratch built harnesses because I never know if they were correctly done. It might be time to dig out a schematic and a volt meter and check the harness pin to pin on each connector and make sure it tracks to the connector on the PCM. Trace each of the grounds and make sure they are good. Is the engine grounded to the chassis with a cable? Check all your power supplies and make sure you're getting 12V to all of them.
You might also find someone local with a known good PCM and see if it works on your car.
You didn't change the injectors did you? If you did, were they the same flow rate?
When I first fired my LS1 it ran like crap and I traced it to the injectors. Took them out and had them ultrasoniclly cleaned and flowed and the car ran perfect. How long had your injectors sat before you tried to start the car?
Phil
I don't like scratch built harnesses because I never know if they were correctly done. It might be time to dig out a schematic and a volt meter and check the harness pin to pin on each connector and make sure it tracks to the connector on the PCM. Trace each of the grounds and make sure they are good. Is the engine grounded to the chassis with a cable? Check all your power supplies and make sure you're getting 12V to all of them.
You might also find someone local with a known good PCM and see if it works on your car.
You didn't change the injectors did you? If you did, were they the same flow rate?
When I first fired my LS1 it ran like crap and I traced it to the injectors. Took them out and had them ultrasoniclly cleaned and flowed and the car ran perfect. How long had your injectors sat before you tried to start the car?
Phil
09-26-2009, 10:53 PM
#5
P0336 - A new crank sensor needs CASE relearn. Some scen tools can do this procedure.
Don't think this would keep it from revving over 1500 rpm, though.
I see the LS1 in the engine compartment, but I'm still having a hard time believing it. You are very brave. Nice job.
Don't think this would keep it from revving over 1500 rpm, though.
I see the LS1 in the engine compartment, but I'm still having a hard time believing it. You are very brave. Nice job.
09-27-2009, 03:50 AM
#6
8 Second Club
iTrader: (1)
Join Date: Nov 2001
Location: the not so stock tribe
Posts: 3,697
Likes: 0
Received 0 Likes
on
0 Posts
did you check if the TPS is reading correctly ?
and the two sensors that can be mixed up are the cam and map sensors if i remember correctly.
what tranny are you using?
and the two sensors that can be mixed up are the cam and map sensors if i remember correctly.
what tranny are you using?
09-28-2009, 08:04 AM
#7
Thanks for everyone's feedback and I have been spending more time on LS1Tech this past weekend and finding tons of information. Now that my car is V8 my Porsche forums are usless.Not to mention the purest on that site do not have the respect of conversions and some consider the car a bastard child now. Let them think that when I am flying by them and can change my plugs and oil under 30min
So to answer some questions:
-- Injectors were on the motor when I purchased and could be a problem. I am going to run some Seafoam injector and cleaner thru them to see if this helps or improves the problems.
-- Car is DBW
-- TPS sensor is showing a reading with my scanner
I did check yesterday all the grounds and found that my right side coil packs were not grounded and showed open load when I Ohm'd to ground. So I made some ground wires from the valve covers to coil pack bracket and then from the heads to the ground so everything now is reading less than .4 to direct ground.
Restarted car and idle is still crappy but less fumes. I suspect I burned out another pair of plugs and will replace again.
So to answer some questions:
-- Injectors were on the motor when I purchased and could be a problem. I am going to run some Seafoam injector and cleaner thru them to see if this helps or improves the problems.
-- Car is DBW
-- TPS sensor is showing a reading with my scanner
I did check yesterday all the grounds and found that my right side coil packs were not grounded and showed open load when I Ohm'd to ground. So I made some ground wires from the valve covers to coil pack bracket and then from the heads to the ground so everything now is reading less than .4 to direct ground.
Restarted car and idle is still crappy but less fumes. I suspect I burned out another pair of plugs and will replace again.
Trending Topics
09-28-2009, 02:59 PM
#8
Here is a reading from my scanner:
ST FTRM1 (%) 14
LT FTRM1 (%) 24
ST FTRM2 (%) 6.2
LT FTRM2 (%) 24.2
MAP (in.hg) 18.9
Engine (RPM) 800
VEH Speed 0
ING ADV (Deg) 21~24 "keeps moving"
IAT (F) 120
MAF (lb/min) 2.2
ABSLT TPS (%) 0
Second Air "Error"
O2S11 .7v 10.9%
O2S12 .4v N/A
O2S21 .8v 8.5%
O2S22 .4v N/A
ST FTRM1 (%) 14
LT FTRM1 (%) 24
ST FTRM2 (%) 6.2
LT FTRM2 (%) 24.2
MAP (in.hg) 18.9
Engine (RPM) 800
VEH Speed 0
ING ADV (Deg) 21~24 "keeps moving"
IAT (F) 120
MAF (lb/min) 2.2
ABSLT TPS (%) 0
Second Air "Error"
O2S11 .7v 10.9%
O2S12 .4v N/A
O2S21 .8v 8.5%
O2S22 .4v N/A
09-29-2009, 02:19 PM
#9
Day # 3 of troubleshooting and I have traced an issue with the spark. I used a timing light on each of the spark plug wires to see if I was getting a spark to each of the plugs and found that cylinder #4 and cylinder #7 are dead.
I swapped coil packs with know good ones and the problem still stays at #4 and #7
Not sure what to check next but think it may be in the PCM.
Any advice?
I swapped coil packs with know good ones and the problem still stays at #4 and #7
Not sure what to check next but think it may be in the PCM.
Any advice?
09-29-2009, 02:23 PM
#10
On The Tree
iTrader: (12)
Join Date: Jul 2008
Location: St.Charles, Illinois
Posts: 155
Likes: 0
Received 0 Likes
on
0 Posts
Does this thing have cats?? grab a noid light and make sure all the injectors are lighting up. I can give you a flow chart on the codes if you would like.
mike
mike
09-29-2009, 02:58 PM
#11
50 psi is too low. LS1 factory psi at the rail is 58-61 psi
Also take this advice to make your life easier. Add grounds... All over the place you cant have too many and if you do a neat job it doesnt look bad or detract from anything but will keep you running smooth for many miles. I added about 6 to my swap. Ran them all to one common grounding block as well. 3 years, runs like a factory built car no gremlins or issues whatsoever
Also take this advice to make your life easier. Add grounds... All over the place you cant have too many and if you do a neat job it doesnt look bad or detract from anything but will keep you running smooth for many miles. I added about 6 to my swap. Ran them all to one common grounding block as well. 3 years, runs like a factory built car no gremlins or issues whatsoever
10-04-2009, 10:00 AM
#18
TECH Resident
Join Date: Dec 2001
Location: Lexington Park, MD
Posts: 922
Likes: 0
Received 0 Likes
on
0 Posts
edit: missed the part about your coil packs being dead. Is this still the case?
Don't give up. You'll find it.
Don't give up. You'll find it.
Last edited by 98blackSS; 10-04-2009 at 10:07 AM.
02-16-2010, 11:21 PM
#20
car still has same problem. Starts up every time but smells real rich and will not Rev past 2K. No spark at #4 and #7 and I have replaced the injectors, intake and TB.
Problem now is I am back in China and can not work on the car till April.
Plan on contacting local turner Jeremy Formato when I return as I convinced the problem has to do with the PCM.
Really hope to get this beast running soon..
Problem now is I am back in China and can not work on the car till April.
Plan on contacting local turner Jeremy Formato when I return as I convinced the problem has to do with the PCM.
Really hope to get this beast running soon..