Announcement

Collapse
No announcement yet.

M20 No Start, Cranks All Day

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • eskimo810
    replied
    Originally posted by efficient View Post
    Damn that sucks. My car was doimg the same bit I found out I had my cps connected to the wrong connector as soon as I put it in its correct connector it fired up but doesnt rev up or idle correctly. Hope you find out what's wromg with ur car
    Thanks. We'll see how it goes :neutral:

    Leave a comment:


  • efficient
    replied
    Damn that sucks. My car was doimg the same bit I found out I had my cps connected to the wrong connector as soon as I put it in its correct connector it fired up but doesnt rev up or idle correctly. Hope you find out what's wromg with ur car

    Leave a comment:


  • eskimo810
    replied
    Anybody? Haven't been able to make any headway on this.

    Leave a comment:


  • eskimo810
    replied
    Bump!

    Leave a comment:


  • eskimo810
    replied
    Back with updates!

    This is the first start after installing the fuel pressure gauge on the intake to the fuel rail.



    I noticed that the only other time it's actually jumped to life like this was when I first tried starting the car after getting everything hooked up, [and this might just be correlative] the fuel system wasn't pressurized at all.


    This is the second attempt, which was filmed approximately 3 minutes after the first.



    The fuel pressure seems to be correct to me, but I'm not sure that I'm doing this test right. Should I be testing the return line from the FPR? Also, I guess it's worth noting that it's been two days since these tests, and the fuel pressure has dropped to around 8 PSI. I know that some pressure is supposed to be retained in the system when the car is off, is there an specific value that it should "rest" at?

    As always, any tips are appreciated!

    Leave a comment:


  • jlevie
    replied
    If this is an 88 or later, C191 (underneath the intake manifold) could be bad. An 87 engine harness doesn't have that connector. In either case the engine harness could be bad or the the injector control section of the DME could be bad. Any of those will prevent the injectors from firing (check with a noid light).

    Leave a comment:


  • eskimo810
    replied
    Originally posted by jlevie View Post
    If there is spark at the coil lead when cranking, you can ignore the apparent continuity test error. That means that the DME is running and that the CPS and coil are good. Which also means that the fuel pump(s) are running. The next diagnostic is to measure fuel rail pressure as the pump(s) or the FPR could be bad. If the rail pressure is correct use a noid light to check for injector firing.
    Alright, thanks for the additional information. I haven't gotten a chance to work on the car at all for more than a week between shitty weather and how much I've been working, but I'll be sure to update when I get a chance.

    If the fuel pressure is good, and the injectors simply aren't firing, what would that be? Would it be the injector wiring harness connector, or could it be something else? Just curious. Regardless, my next step will be to test the fuel pressure.

    Leave a comment:


  • jlevie
    replied
    If there is spark at the coil lead when cranking, you can ignore the apparent continuity test error. That means that the DME is running and that the CPS and coil are good. Which also means that the fuel pump(s) are running. The next diagnostic is to measure fuel rail pressure as the pump(s) or the FPR could be bad. If the rail pressure is correct use a noid light to check for injector firing.

    Leave a comment:


  • Kozworth
    replied
    Well, I would much rather test fuel pressure then trace an open from Pin 36 to the main relay. A failed continuity test basically means there is an open in the circuit, so this could be literally anywhere from the stretch of the pcm connector to the relay box.

    My friend picked up an e36 which drove perfect, then he said one day it just died. Thats why he was selling it, I looked into it and the fuel pump was beat. It wouldnt even move with 12v to it. With a continuity test, it was open. I threw in a new pump and its been my daily. So pumps don't always give warning with a "whine" or long cranking, but thats the more typical way they go. I just wanted to share a personal experience with a kamikazi fuel pump.

    Leave a comment:


  • eskimo810
    replied
    morning bump.

    Leave a comment:


  • eskimo810
    replied
    Originally posted by Kozworth View Post
    Test with a fuel pressure gauge. How could you tell if the pump puts out 10psi, or 40psi? Both will shoot out quite a bit.

    If you have correct pressure, Take a bulb (I use an old bulb with harness, so its power/ground) and remove the injector harness off an injector. Connect to the harness your concoction of a zener diode. If the light flashes with the crank, then you have the pcm grounding it. Try on injector 1 & 2. Pcm grounds 1/3/5 at once and 2/4/6 at once. If there is no flash, check for 12v before the c191. If there is, cut the c191 out, resplice the connecter with male/female connectors and enjoy.
    I'll look into sourcing a fuel pressure gauge. I live in a small town and don't have transportation out of here at the moment ( :(), but I am friendly with a local shop that might be able to help me out. Is there something else I can do at the moment? I'd still like to know what the failed continuity test from DME 36 to main relay 85 means.

    Do I have any reason to doubt the fuel pump other than knocking it off my list of possible problems? The car was running like a champ before I did this swap, is there a reasonable chance that the fuel pump could falter as the car sits?

    Leave a comment:


  • Kozworth
    replied
    Originally posted by eskimo810 View Post
    I should have said this earlier, but the fuel pump is good. Sends a nice healthy flow of fuel out of the line leading to the fuel rail. A good blue spark is also present.
    Test with a fuel pressure gauge. How could you tell if the pump puts out 10psi, or 40psi? Both will shoot out quite a bit.

    If you have correct pressure, Take a bulb (I use an old bulb with harness, so its power/ground) and remove the injector harness off an injector. Connect to the harness your concoction of a zener diode. If the light flashes with the crank, then you have the pcm grounding it. Try on injector 1 & 2. Pcm grounds 1/3/5 at once and 2/4/6 at once. If there is no flash, check for 12v before the c191. If there is, cut the c191 out, resplice the connecter with male/female connectors and enjoy.

    Leave a comment:


  • bddog
    replied
    Make sure the number one spark plug is firing when the number one cylinder is at top dead center.

    Leave a comment:


  • eskimo810
    replied
    I'm fairly lost at this point. Just tried cranking it in the dark and I can see the distributor flashing where the timing belt cover meets the head, though I'm not sure what that means.
    Last edited by eskimo810; 06-23-2013, 11:37 AM.

    Leave a comment:


  • eskimo810
    replied
    I continued with the troubleshooting guide and was productive with coming up with problems, though I don't know what it all means exactly.

    "3) Check for continuity from DME 36 to main relay 85 and from DME 3 to fuel
    pump relay 85."

    Continuity to the fuel pump relay was good, but the test failed for the main relay. Subsequent instructions provided me with further discrepancies, so I'd like to imagine that the problem is a result of the lack of continuity from DME 36 to the main relay.

    Thanks for the help and suggestions so far!

    Leave a comment:

Working...
X