Moparts
5.7 hemi swap won't start?
Posted By: xpsyclonex2002
5.7 hemi swap won't start? - 12/17/11 12:05 AM
I've been working on my swap for some time now. I have the motor swapped in and everything hooked up. Every time I try to start it, it turns over but won't fire up. I can spray starting fluid into it and it will run for a few seconds but then when the starting fluid runs out it shuts off. I called the dealership and they told me that the anti-theft kills both fuel and ignition so I don't think that's the problem. The injectors aren't getting anything. Anyone got any ideas?
FYI - the fuel injection is being done with a Walbro GSS 255 in tank pump running into a 99 corvette fuel filter that has a built in regulator.
Posted By: stumpy
Re: 5.7 hemi swap won't start? - 12/17/11 12:33 AM
Is the pump getting power?
Posted By: OzHemi
Re: 5.7 hemi swap won't start? - 12/17/11 12:52 AM
Do you have fuel pressure at the rails ?
Posted By: 69rrconvert
Re: 5.7 hemi swap won't start? - 12/17/11 01:01 AM
I had the same issue with my 5.7 swap. It turned out to be the fuel injectors were gummed up from sitting. My 5.7 came out of a salvage yard and had sat for awhile before I tried to get it running. I pulled the injectors and placed them in a bowl filled with paint reducer and let it sit overnite. The next morning the reducer was brown in color. Reinstalled the injectors and fired right up
Posted By: JDMopar
Re: 5.7 hemi swap won't start? - 12/17/11 01:14 AM
Quote:
I had the same issue with my 5.7 swap. It turned out to be the fuel injectors were gummed up from sitting. My 5.7 came out of a salvage yard and had sat for awhile before I tried to get it running. I pulled the injectors and placed them in a bowl filled with paint reducer and let it sit overnite. The next morning the reducer was brown in color. Reinstalled the injectors and fired right up
I'll remember that! I've got a 2006 5.7 Hemi with 6000 miles on it, that's been sitting since 2006. I roll it over with a breaker bar, but it will be a year or 2 before it runs again in my 70 Duster. Original poster...please let us know what you find that's keeping it from running if this isn't it. 
Posted By: xpsyclonex2002
Re: 5.7 hemi swap won't start? - 12/17/11 02:42 AM
Quote:
I had the same issue with my 5.7 swap. It turned out to be the fuel injectors were gummed up from sitting. My 5.7 came out of a salvage yard and had sat for awhile before I tried to get it running. I pulled the injectors and placed them in a bowl filled with paint reducer and let it sit overnite. The next morning the reducer was brown in color. Reinstalled the injectors and fired right up
Interesting. I never thought of that.
Posted By: xpsyclonex2002
Re: 5.7 hemi swap won't start? - 12/22/11 06:28 AM
Ok. Soaked the injectors in acetone. Still no joy. Anyone else got any ideas?
Posted By: MR_P_BODY
Re: 5.7 hemi swap won't start? - 12/22/11 06:34 AM
Quote:
Ok. Soaked the injectors in acetone. Still no joy. Anyone else got any ideas?
Like was asked... do you have fuel pressure at the rail
Posted By: 1_WILD_RT
Re: 5.7 hemi swap won't start? - 12/22/11 06:49 AM
As far as cleaning injectors...
http://oldfuelinjection.com/?p=82Beyond that as mentioned do you have pressure in the rail... 12 volts to the injectors, pulsed ground signal. Do you have a noid light to test the signal?
Posted By: BEINGmeISaCRIME
Re: 5.7 hemi swap won't start? - 12/22/11 05:46 PM
Definitely get a fuel pressure gauge and put on it. Could be possible it isn't getting enough pressure, which would cause problems. Easy way to see if injectors are working is using a probe rod stethoscope on the injectors, you should be able to hear them clicking.
Posted By: OzHemi
Re: 5.7 hemi swap won't start? - 12/22/11 05:57 PM
Quote:
Quote:
Ok. Soaked the injectors in acetone. Still no joy. Anyone else got any ideas?
Like was asked... do you have fuel pressure at the rail
That is why I had asked...when I did my LS1 swap, I checked for fuel pressure before even trying to fire it. (I have a gauge right on the aeromotive regulator though so makes it easy)
Once you verify you have proper fuel pressure then start working your way from there with injectors getting a signal and working, etc.
Posted By: xpsyclonex2002
Re: 5.7 hemi swap won't start? - 12/24/11 09:58 PM
OK Guys, I have had some time to work on this. Putting a NOID test on it shows that I have no signal going to any of the injectors. I put a fuel gauge at the rail. I can't get it to run so I am only able to read it with the key turned. I can hear the fuel pump running for a second or two at most then it stops. The reading I get is at around 10PSI! I cut the wire coming of the starter relay and hard wired it directly to the battery. That gives me nearly 60 psi at the rail! I know I'm supposed to have about 55psi to run the motor. Why am I not getting it unless I come directly off the battery?
Posted By: 540challenger
Re: 5.7 hemi swap won't start? - 12/24/11 11:22 PM
What computer are you using to run your Hemi?? Must aftermarket systems require you to run directly to the battery, otherwise everything else will interfere with what the computer is seeing. Also the battery must be 100% fully charged and no bad cells.
Posted By: xpsyclonex2002
Re: 5.7 hemi swap won't start? - 12/25/11 12:14 AM
I'm running the 2005 computer that came with the motor. I'm not sure what you mean by "require you to run directly to the battery"? I am using a harness from Street and Performance that was made just for this swap.
Posted By: xpsyclonex2002
Re: 5.7 hemi swap won't start? - 12/25/11 05:56 PM
Quote:
I'm running the 2005 computer that came with the motor. I'm not sure what you mean by "require you to run directly to the battery"? I am using a harness from Street and Performance that was made just for this swap.
bump
Posted By: MR_P_BODY
Re: 5.7 hemi swap won't start? - 12/25/11 06:11 PM
Quote:
OK Guys, I have had some time to work on this. Putting a NOID test on it shows that I have no signal going to any of the injectors. I put a fuel gauge at the rail. I can't get it to run so I am only able to read it with the key turned. I can hear the fuel pump running for a second or two at most then it stops. The reading I get is at around 10PSI! I cut the wire coming of the starter relay and hard wired it directly to the battery. That gives me nearly 60 psi at the rail! I know I'm supposed to have about 55psi to run the motor. Why am I not getting it unless I come directly off the battery?
When you turn the key to the on position you get a
3 second pump run time... you only get 3 key on pump
runs then the engine has to turn over so it sees that
the engine is tuning(thinks its running)... as to
no power to the injectors... that can be multiple
things
Posted By: OzHemi
Re: 5.7 hemi swap won't start? - 12/25/11 06:12 PM
The pump running just for a second and shutting off when you turn the key to on sounds normal (that is how most cars seem to be) should just prime the system them when you turn the key to start it should and then running it will run the pump as normal. If you only have 10 psi it does sound like there is an issue ?
How does your fuel pump get power normally, is it through the loom getting a trigger from the PCM ?
I've never done a Hemi, but with the LSx setups and using factory PCMs you have to make sure you have them burned to remove the anti-theft stuff that turns stuff off after cranking from memory.
Posted By: NITROUSN
Re: 5.7 hemi swap won't start? - 12/25/11 09:09 PM
That still is an OBDll system so do a system test and pull the codes. That may show something.
Posted By: xpsyclonex2002
Re: 5.7 hemi swap won't start? - 12/25/11 10:58 PM
Quote:
Quote:
OK Guys, I have had some time to work on this. Putting a NOID test on it shows that I have no signal going to any of the injectors. I put a fuel gauge at the rail. I can't get it to run so I am only able to read it with the key turned. I can hear the fuel pump running for a second or two at most then it stops. The reading I get is at around 10PSI! I cut the wire coming of the starter relay and hard wired it directly to the battery. That gives me nearly 60 psi at the rail! I know I'm supposed to have about 55psi to run the motor. Why am I not getting it unless I come directly off the battery?
When you turn the key to the on position you get a
3 second pump run time... you only get 3 key on pump
runs then the engine has to turn over so it sees that
the engine is tuning(thinks its running)... as to
no power to the injectors... that can be multiple
things
Can you guys give me a quick rundown of the most common causes of the injectors not getting power and how to test for them? I am no mechanic, just a guy who is crazy enough to tackle a project like this with no help except the forums. 
Posted By: MR_P_BODY
Re: 5.7 hemi swap won't start? - 12/25/11 11:17 PM
Can you guys give me a quick rundown of the most common causes of the injectors not getting power and how to test for them? I am no mechanic, just a guy who is crazy enough to tackle a project like this with no help except the forums.
Well, the computer drives the injectors with inputs
from the different sensors... cam, crank, temp and
throttle position sensors... basically the computer
closes the circuit to ground to fire them and based
upon the rpm and load tells them how long(duty cycle)
to hold them open.... from just what I've read here
your crank sensor is working(I believe) so my first
plan of attack would be to get a DRB on it for the
codes and yours should be a DRB2... without running
the codes from the DRB2 your guessing and just
throwing money at it... most any parts stores have
them... you might be able to rent theirs to take it
home to use... if you could drive it there its usually
free.... BUT as a guess... it could be the cam sensor
but thats guessing
Posted By: JDMopar
Re: 5.7 hemi swap won't start? - 12/26/11 12:13 AM
When you bought the harness from Street & Performance, did you send your computer that came with your motor to get it reflashed? Just from what I have read on their website,that needs to be done...and they will need the VIN number of the vehicle the motor came out of in order to disable the antitheft dealie in the ECM.
Posted By: xpsyclonex2002
Re: 5.7 hemi swap won't start? - 12/26/11 07:05 AM
They told me when I bought the harness that the computer didn't need to be flashed because of the year. They said that 2004 and 2005 didn't have the anti-theft. I have since learned that some do. Called the dealership and gave them the VIN and they couldn't tell me if it had anti-theft but based on the fact that the motor would run for short periods of time ( 1-10 seconds) on starting fluid, the anti theft can't be there because the coils are firing.
Posted By: NITROUSN
Re: 5.7 hemi swap won't start? - 12/26/11 05:05 PM
What are the codes??????????????????
Posted By: JDMopar
Re: 5.7 hemi swap won't start? - 12/27/11 12:40 AM
Ok...if it's not that, do you have a connector on the harness to hook up a scan tool like NitrousN suggested?
Posted By: xpsyclonex2002
Re: 5.7 hemi swap won't start? - 12/27/11 01:49 AM
Yeah. It comes with an OBDII connector on it. I have scanned it before. No codes that should give me troubles like this. I'll try to borrow a scanner and get the codes again.
Posted By: OzHemi
Re: 5.7 hemi swap won't start? - 12/27/11 01:54 AM
Just to double check to see if your injectors are getting power and narrow down that is not a fuel supply issue, you can also unplug the injector wiring plug off of it, and take a 194 bulb, straighten out the the little wires for the contacts and plug it into the injector harness plug. Then try and start the engine. The bulb should pulse with light if you are getting power there. If you are not getting any power and you have no codes at all (which seem odd?) I would go back to S & P and see if they have a tech person to try and trouble shoot it and verify the computer is not an issue and that there are no issues with the loom itself.
(For what they charge for thier stuff, they sure should have a good tech department I would think)
Posted By: JDMopar
Re: 5.7 hemi swap won't start? - 12/27/11 04:37 AM
"(For what they charge for thier stuff, they sure should have a good tech department I would think)"
I'm having to part out a 71 Hemi Cuda conv. to be able to put a 5.7 Hemi in a 70 /6 Duster body!
Posted By: OzHemi
Re: 5.7 hemi swap won't start? - 12/27/11 04:51 AM
Posted By: xpsyclonex2002
Re: 5.7 hemi swap won't start? - 12/28/11 06:01 AM
sounds.......complicated.
I sent the computer off today to have it flashed and make sure that there were no anti theft issues. I have never gotten a clear answer on that. I read through some forums on the swap and it appears that on starting fluid the engine can "diesel" for a few seconds even with anti theft. It was something I planned to do anyway to have them change it some.
Posted By: xpsyclonex2002
Re: 5.7 hemi swap won't start? - 01/12/12 05:02 AM
OK> I have run the OBDII on the motor and come up with the following codes, P0101, P0108, P0104, P0102, and P0110. I have sent the computer off and had it flashed to removed anti theft and reinstalled it. The motor didn't behave any different. It would crank but not turn over. I checked the fuel pressure and it was down around 10psi. I ran a wire straight off the battery to the fuel pump and it jumps the pressure up to 58 psi. I confirmed the voltage drop to the computer when the key is in the START position. I took the same wire that I ran directly off the battery to feed the pump and also fed 12V straight to the computer. Now the motor turns over and runs for a second at very high RPM then tries to stall out but before stalling out revs back up again for a second then dies.
Posted By: xpsyclonex2002
Re: 5.7 hemi swap won't start? - 01/12/12 06:43 PM
bump
Posted By: wldtm
Re: 5.7 hemi swap won't start? - 01/12/12 11:43 PM
For an 05 Truck only one of those codes come up? What is the p# of the PCM???
It sounds like you have a wiring issue if supplying battery power to the fuel pump increases fuel psi from 10 to 55psi.
I would double the wiring connections you had to make. BTW A street and performance harness is most likely not built by s&p. You might want to try hotwireauto. The Squires most likely built the harness.
Just my
If you want PM me your cell, and I will trouble shoot over the phone.
Justin
Posted By: xpsyclonex2002
Re: 5.7 hemi swap won't start? - 01/12/12 11:58 PM
I thought the same thing about Squire building the harnesses for S&P. I called Squire directly about the issues and found out that they stopped supplying S&P with Harnesses about 3 years ago. They were still helpful but couldn't solve my problems.
Posted By: wldtm
Re: 5.7 hemi swap won't start? - 01/13/12 01:14 AM
that dropped my confidence a little bit now.
part#???
Posted By: xpsyclonex2002
Re: 5.7 hemi swap won't start? - 01/13/12 05:54 AM
I think I may be on track for a solution. I went back and read the "hemi in your ole mopar" thread and found that they had the same problems I am having. Looks like I need a relay from my ignition to the computer to keep the 12v supplied and there is likely a pair of wires wired wrong in my harness at the starter relay. Film at 11..........
Posted By: JDMopar
Re: 5.7 hemi swap won't start? - 01/14/12 04:03 PM
Posted By: xpsyclonex2002
Re: 5.7 hemi swap won't start? - 02/27/12 01:21 AM
I was right. There voltage drop when the key was turned to START to the computer was the problem. We fixed it with a pair of relays. The motor started fine. Then we spun a bearing......FML.
Posted By: 808CUDA
Re: 5.7 hemi swap won't start? - 02/27/12 01:42 AM
Too bad I just saw this post now. Ran into the same situation with my Cuda years ago before it became popular.
You need to have a constant 12v at the ECM "WHILE CRANKING" which in a typical older car the ignition switch kills voltage output except for the starter solenoid.
Glad you finally fixed it. Squier failed to put that in their wiring instructions and surprised they didn't supply it by now.
Posted By: xpsyclonex2002
Re: 5.7 hemi swap won't start? - 02/29/12 05:38 AM
It's funny that you posted that. It was your thread that I used to diagnose the problem! Well that is the least of my problems now. It appears that I spun a bearing.
Posted By: 808CUDA
Re: 5.7 hemi swap won't start? - 02/29/12 05:45 AM
Glad the thread helped
Sorry about your bearing tho
