TBI install progress

Discussion in 'Injection Tech' started by JayKray, Aug 11, 2016.


  1. JayKray

    JayKray Farmall Cub

    Joined:
    Mar 30, 2004
    Messages:
    88
    Likes Received:
    9
    Trophy Points:
    8
    Location:
    Coventry, CT
    ok, I cranked the FPR up as far as it would go. Better, but still on the lean side. So what's next? Can I get a stiffer spring in there?
     

    Attached Files:

  2. Bill USN-1

    Bill USN-1 Moderator Staff Member Moderator

    Joined:
    Dec 25, 2002
    Messages:
    17,068
    Likes Received:
    257
    Trophy Points:
    83
    Location:
    Whidbey Island, WA
    I can adjust the tune the rest of the way but if you really have 5.7 injectors with the number 5235206 on them, and the regulator spring is not broken and adjusted to the top of the slot when installed, then that setup would be really rich on the engine.
    Or you have a 392 not a 345.
    Have you verified the injector numbers?
    Have you removed the regulator canister and verified the spring is good?
    Have you looked at the number stamped into the passengers side of the block just above the motor mount ?
    Try to take pics of the above and post up.
    I have no problem adjusting the tune but I don't want to adjust the tune for a mechanical problem that will come back later.
     
  3. JayKray

    JayKray Farmall Cub

    Joined:
    Mar 30, 2004
    Messages:
    88
    Likes Received:
    9
    Trophy Points:
    8
    Location:
    Coventry, CT
    Yes, I was wondering if the injectors were original to the 5.7 that the TBI came out of. I'll take a look for the numbers tonight. The tops of the injectors are a bit rusty, I hope I can make them out.
    I rebuilt the tbi on saturday including a new regulator diaphragm and the spring was intact and looked healthy.
    Yes, my block is stamped 345.
    My buddy who was very familiar with the GM TBI system said that my injector spray pattern looked great. He mentioned that when you open the throttle with a bad injector the pattern will get narrow, while mine actually got a bit wider which is good.
     
  4. Bill USN-1

    Bill USN-1 Moderator Staff Member Moderator

    Joined:
    Dec 25, 2002
    Messages:
    17,068
    Likes Received:
    257
    Trophy Points:
    83
    Location:
    Whidbey Island, WA
    I use a little metal acid brush with the bristles cut shorter or one of the brass wire tooth brushes to scrub the tops.
    The narrowing spray pattern can also be a drop in pressure as the flow requirements increases.
     
  5. JayKray

    JayKray Farmall Cub

    Joined:
    Mar 30, 2004
    Messages:
    88
    Likes Received:
    9
    Trophy Points:
    8
    Location:
    Coventry, CT
    OK, so I got the drivers injector cleaned up enough to confirm that it is a GM5235206, however I couldn't get the passenger side clean enough to read.
    It just so happens that I have a o2 sensor installed in each downpipe, but the TBI system is currently only running off of the passenger side. I am going to swap the system to read off the driver's side sensor and see how the BLMs compare. If there is negligible difference, can I assume that the unreadable injector is also a 5206, or is there too much mixing in the intake to know? drivers injector.jpg injectors.jpg
     
  6. Bill USN-1

    Bill USN-1 Moderator Staff Member Moderator

    Joined:
    Dec 25, 2002
    Messages:
    17,068
    Likes Received:
    257
    Trophy Points:
    83
    Location:
    Whidbey Island, WA
    Unless the O2 sensor is bad, or there is a vacuum leak, there won't really be any difference from side to side. If you look at the intake there are 2 cyl runners from each injector that feed each side.
    So you are sampling both on each side.
     
  7. JayKray

    JayKray Farmall Cub

    Joined:
    Mar 30, 2004
    Messages:
    88
    Likes Received:
    9
    Trophy Points:
    8
    Location:
    Coventry, CT
    OK, I swapped to the drivers side o2 sensor an as Bill predicted, there was very little change. My BLM still had a bunch of 135-141 numbers. I went around the intake and TBI with an unlit propane torch and didn't notice any change in idle, so I think I am pretty decent as far as vacuum leaks go. Attached are some pictures of the block and head stampings. I believe these all prove that it is a 345 and not a 392. So, I guess I am ready for a new chip, unless there is anything else I should check.

    block number.jpg head number.jpg
     
  8. JayKray

    JayKray Farmall Cub

    Joined:
    Mar 30, 2004
    Messages:
    88
    Likes Received:
    9
    Trophy Points:
    8
    Location:
    Coventry, CT
    OK, I got a new chip from Bill over the weekend and installed it last night. Thanks Bill!
    As I was installing the new chip, it occurred to me what might be my intake "leak". I have a fuel vapor canister and I'm not sure it's appropriate for this setup.

    So, I attached two BLMs and Logs of some quick runs after the chip install. The first set is with the canister hooked up as it has been, the second is with the TBI port to the canister plugged. It does look slightly richer with the port plugged, but not significant enough to bring it to where Bill estimated where it should be as compared to other 345 engines with his original starter chip.

    I have also attached pictures of my vapor canister connections and TBI connections. The canister has three connections. I have the "carb" one plugged, the tank to the tank, and the purge to the passenger side port at the front of the TB. The center front port on the TB is connected to the PCV and the drivers is plugged.
     

    Attached Files:

  9. JayKray

    JayKray Farmall Cub

    Joined:
    Mar 30, 2004
    Messages:
    88
    Likes Received:
    9
    Trophy Points:
    8
    Location:
    Coventry, CT
    Here are the BLM and Log from the drive to work this morning. This is with the new chip and the vapor canister connected as it has been from the beginning.
     

    Attached Files:

  10. Bill USN-1

    Bill USN-1 Moderator Staff Member Moderator

    Joined:
    Dec 25, 2002
    Messages:
    17,068
    Likes Received:
    257
    Trophy Points:
    83
    Location:
    Whidbey Island, WA
    We have discussed this many times here.
    There should be no vacuum connections other then the brake booster, PCV valve and map sensor.
    If you have anything else connected.....disconnect and plug.
    Brake booster should connect to the back of the manifold, normally where the PCV is connected.
    PCV should connect to the large port on the front of the TBI. Run the hose under the manifold.
    Map connects to the back of the TBI.
    NO EGR, NO VAPOR CANISTER.
    The valve cover flame arrester should connect to the air cleaner.

    The BLM's are about as close as you can get on a tune with the vacuum leak you have with the canister connected.
    The system can't have vacuum or exhaust leaks.
     
    Last edited: Oct 18, 2016
  11. Bill USN-1

    Bill USN-1 Moderator Staff Member Moderator

    Joined:
    Dec 25, 2002
    Messages:
    17,068
    Likes Received:
    257
    Trophy Points:
    83
    Location:
    Whidbey Island, WA
    Back in the beginning we discussed connections.
     
  12. JayKray

    JayKray Farmall Cub

    Joined:
    Mar 30, 2004
    Messages:
    88
    Likes Received:
    9
    Trophy Points:
    8
    Location:
    Coventry, CT
    OK, I properly plugged the two small ports at the front of the TBI.
    I had already replaced the line from the MAP to the back of the TBI with fresh rubber.
    I rerouted the line between the PCV and the large center port at the front of the TBI. This is a nice touch as it further cleans up the engine compartment.
    I have hydroboost, so I don't have a line to the brake booster.
    The flame arrestor was already plumbed to the air cleaner.
    I removed my vapor recovery tank, plugged all the extra holes at the tank, and ordered a new vented fuel cap. I'm not super excited about not using the charcoal canister, but we will see if it affects the smell of my garage.

    I still need to reset my idle and IAC and then it might be until next week before I get to log some more data.
     
  13. JayKray

    JayKray Farmall Cub

    Joined:
    Mar 30, 2004
    Messages:
    88
    Likes Received:
    9
    Trophy Points:
    8
    Location:
    Coventry, CT
    OK, so I reset everything and drove it a few times. I watched the BLMs and tweaked the fuel pressure regulator a few times until I ended up where it is in the attached files which seems pretty close to the magic 128. I noticed a few knock counts at the end of the run, so I might want to back off the initial timing timing a tad.
     

    Attached Files:

  14. Bill USN-1

    Bill USN-1 Moderator Staff Member Moderator

    Joined:
    Dec 25, 2002
    Messages:
    17,068
    Likes Received:
    257
    Trophy Points:
    83
    Location:
    Whidbey Island, WA
    As mentioned in the tuning threads, I normally shoot for a little rich around 126.
    I don't see any ping only engine noise false knock.
    That's the problem with having too much information.
    It can be misread.
    Like having an AFR gauge in the dash.
     
    hunch98 likes this.
  15. JayKray

    JayKray Farmall Cub

    Joined:
    Mar 30, 2004
    Messages:
    88
    Likes Received:
    9
    Trophy Points:
    8
    Location:
    Coventry, CT
    Just a little update.
    I was improving my fuel line connections last night, went to Aeroquip lines and AN fittings which came out pretty clean. While I was doing that, I verified fuel pressure. I got a solid 14psi on the feed all the way to full throttle and Zero on the return. I'm pretty sure that is all good.
    I still have not found any vacuum leaks and am a little weirded out by how special my tune needs to be.
    I still am also getting knock at heavy throttle while climbing a hill. I have brought the initial timing to ~6 degrees ATDC and that is as far as I can go unless I remount my ignition control module.

    Two thoughts:
    1. The welch plug under my EGR on my intake manifold is leaking? I have pointed an unlit propane torch under there and haven't noticed it, I can't hear a whistle or anything weird at idle, but I do have small amounts of coolant that ends up on my valley pan from time to time, so I have reason to believe that the plugs that cover the air passages might also be compromised. I'm not excited about pulling the manifold, but that might be next.

    2. My mechanical cam timing might be off? Couldn't this be causing me to both pull more air that expected and result in a compression ratio that would cause premature ignition (knock)? Is there an easy way to check this? I guess a compression test would be the easiest, but is there a way to check when a certain valve starts to lift vs crank position?

    Thanks,
    Jay
     
  16. Bill USN-1

    Bill USN-1 Moderator Staff Member Moderator

    Joined:
    Dec 25, 2002
    Messages:
    17,068
    Likes Received:
    257
    Trophy Points:
    83
    Location:
    Whidbey Island, WA
    I'm not understanding your comments on timing.
    Timing is BTDC not ATDC.
    What do you mean by initial timing.
    Base timing/distributor is set to 0* above 400rpm the ECM takes control and uses the timing table.

    For the cam, you can do a compression check, you can also remove the rocker shaft and use a dial indicator on the tip of the push rod to measure lift as you rotate the crank.
    You will need a degree wheel and a pointer and the cam specs.
    Lots of write up and videos on haw to degree a cam.
     
  17. JayKray

    JayKray Farmall Cub

    Joined:
    Mar 30, 2004
    Messages:
    88
    Likes Received:
    9
    Trophy Points:
    8
    Location:
    Coventry, CT
    Bill, maybe I misunderstood, but I thought you asked me to back off the timing 5 degrees. I'm on my phone now, but I'm referring to something you stated in this thread.
     
  18. Bill USN-1

    Bill USN-1 Moderator Staff Member Moderator

    Joined:
    Dec 25, 2002
    Messages:
    17,068
    Likes Received:
    257
    Trophy Points:
    83
    Location:
    Whidbey Island, WA
    I didn't go back a reread the thread.
    Last post was 2016.
    If you do not have the correct timing table and just trying to run off a JY factory chip, then you may need to retard it.
    But normally the lean burn GM tune requires you to add timing.
    So if your actually pinging, why?
     
  19. JayKray

    JayKray Farmall Cub

    Joined:
    Mar 30, 2004
    Messages:
    88
    Likes Received:
    9
    Trophy Points:
    8
    Location:
    Coventry, CT
    Exactly, why am I pinging? I'll do compression test early next week. I have the last chip that you burned for me Bill, not stock GM, not the first one you have me. It only pings under heavy throttle up a hill. If I downshift, it sounds fine. It's definitely ping, I've seen this in the logs to back up my ear.

    Sent from my SM-G930V using Tapatalk
     
  20. Bill USN-1

    Bill USN-1 Moderator Staff Member Moderator

    Joined:
    Dec 25, 2002
    Messages:
    17,068
    Likes Received:
    257
    Trophy Points:
    83
    Location:
    Whidbey Island, WA
    So did retarding the timing stop the pinging?
     

Share This Page