2G Car won't start

Posted by Jsmo123, May 17, 2018 at 1:13 PM

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  1. Jsmo123

    Jsmo123 Probationary Member

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    Danville, Kentucky
    Heres some things to take in mind -
    1. Fuel pump is good.
    2. I have tested 2 ecus (one known to be good).
    3. Fuel pump circuit is solid. (I ground pin 8 on the 26 pin connector (fuelpump ground)) and the fuelpump will turn on
    4. Turn the key without ground and the fuel pump does not kick on/prime.
    5. Cranks fine
    6. Replaced crank pos sensor.
    7. Fuel rail has no fuel coming out.

    Cant rewire because ecu has no control on fuelpump ground.
    I hardwired fuelpump but car wouldnt stay on (got it to run good for a couple seconds)

    I am at a loss for fixes. Its a parts cannon at this point and looking for better suggestions (relay clicks fine too, also has correct ohms)
     

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    Last edited: May 17, 2018 at 1:21 PM
  2. 1990TSIAWDTALON

    1990TSIAWDTALON Moderator

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    Independence, Kansas
    Getting 12V to the pump and checked at the pump???
     
    My DSM:
    1992 Eagle Talon TSi AWD

    Street Build

    14b   automatic
    1990 Eagle Talon TSi AWD

    13.620 @ 108.460 MPH
    1990 Eagle Talon TSi AWD

    13.612 @ 107.760 MPH
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  3. Jsmo123

    Jsmo123 Probationary Member

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    Danville, Kentucky
    Can't really get 12volts at the pump unless I am grounding it myself because the ecu wont complete the circuit.
     
  4. 1990TSIAWDTALON

    1990TSIAWDTALON Moderator

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    Well, what I am getting at here is, if you have a 12v source that comes on with the key, rewire that pump, like we all do, and you are only using the 12v source as a signal wire for the RELAY that you will use to do the rewire. You will have the relay grounded already, just waiting to see 12v+ to activate it and then the pump, if good, will run. It will be getting direct 12V+ from the battery at that time. Do you get what I am trying to describe? :)
     
    My DSM:
    1992 Eagle Talon TSi AWD

    Street Build

    14b   automatic
    1990 Eagle Talon TSi AWD

    13.620 @ 108.460 MPH
    1990 Eagle Talon TSi AWD

    13.612 @ 107.760 MPH
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  5. Jsmo123

    Jsmo123 Probationary Member

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    Joined Thursday
    Danville, Kentucky
    There will never be a 12v signal because nothing happens when the key is turned on the fuel pump circuit. That 12v cant be sent without the ground. When I pin the fuel pump relay there is only 12 volts if I stick a ground in the white/red wire hole. Maybe I am missing something. I did the entire fuel pump rewire and it did not work.

    Also, correct me if I am wrong but I believe that the car should stay running when the pump is hardwired, because of the fuel return line. It wont stay on but for a second.
     
  6. 1990TSIAWDTALON

    1990TSIAWDTALON Moderator

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    You can work around that with any 12v signal that comes on with the key.
    Just to be clear, the relay will only need the positive side of the 12 volts, that is why I put 12v+ on the post. It doesn't care about ground. The pump ground is good isn't it? If so, applying 12v+ to a relay and grounding (ANYWHERE) the other pole of the relay, it will click, applying the other 2 terminals together, which would be the fuel pump 12v+ wire for its operation and the new rewire wire coming from the battery.
    Maybe I am missing something.
     
    My DSM:
    1992 Eagle Talon TSi AWD

    Street Build

    14b   automatic
    1990 Eagle Talon TSi AWD

    13.620 @ 108.460 MPH
    1990 Eagle Talon TSi AWD

    13.612 @ 107.760 MPH
    Loading...
  7. Jsmo123

    Jsmo123 Probationary Member

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    Danville, Kentucky
    Okay, lets say I wire this, why would the car not run correctly with the fuel pump hardwired? Logically if that wont work neither will a rewire. You should be able to hardwire the pump and have it still work and the car would run normally.
     
  8. dustyboner

    dustyboner Proven Member

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    abq, New Mexico
    it wont run with the fuel pump hardwired because for one reason or another either your injectors aren't squirting fuel in the cylinders or your spark plugs aren't making a spark

    how about some info on your car?
     
  9. Gandalf

    Gandalf Proven Member

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    ll, Oregon
    the cas is what the ECU uses to fire injectors. i'm not sure off the top of my head if it's cas or crank sensor which kicks on the fuel pump. check your cas.
     
    My DSM:
    1997 Eagle Talon TSi AWD

    Street Build

      manual
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  10. Jsmo123

    Jsmo123 Probationary Member

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    Danville, Kentucky
    The car ran. Sounded great. Just for not very long. Its struggling. It almost fires but wont.
    I was driving it and it sounded like a coupler fell off and hasnt started since. The VIN says that car is a 420a (engine is 4g63t), maybe a swapped dash. Huge security system wiring mess under dash; however I highly doubt thats causing the issue.
     
    Last edited: May 17, 2018 at 2:33 PM
  11. 1990TSIAWDTALON

    1990TSIAWDTALON Moderator

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    I have obviously missed something.....
     
    My DSM:
    1992 Eagle Talon TSi AWD

    Street Build

    14b   automatic
    1990 Eagle Talon TSi AWD

    13.620 @ 108.460 MPH
    1990 Eagle Talon TSi AWD

    13.612 @ 107.760 MPH
    Loading...
  12. dustyboner

    dustyboner Proven Member

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    abq, New Mexico
    if its a 420a, did you check the ASD relay or just the fuel pump relay?
     
  13. Jsmo123

    Jsmo123 Probationary Member

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    Danville, Kentucky
    Its 4g63t guys. 420a dash. Just saying it couldve been swapped from a 420a to the 4g63. Probably not

    When cranking the car it starts to start (pops from exhaust) but just doesnt quite get there. We have had it running with a hardwire to the pump. (It only ran for a couple seconds)
     
    Last edited: May 17, 2018 at 2:42 PM
  14. 1990TSIAWDTALON

    1990TSIAWDTALON Moderator

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    Independence, Kansas
    You have had it running with a hardwire to the pump......that is what I was describing in the rewire post, only turning off the hardwire positive with a relay. What part am I missing?
     
    My DSM:
    1992 Eagle Talon TSi AWD

    Street Build

    14b   automatic
    1990 Eagle Talon TSi AWD

    13.620 @ 108.460 MPH
    1990 Eagle Talon TSi AWD

    13.612 @ 107.760 MPH
    Loading...
  15. Jsmo123

    Jsmo123 Probationary Member

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    Joined Thursday
    Danville, Kentucky
    You are missing the fact that it would not stay running. It would shut off with the pump hardwired. It was not constant.
     
  16. dustyboner

    dustyboner Proven Member

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    abq, New Mexico
  17. Jsmo123

    Jsmo123 Probationary Member

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    Joined Thursday
    Danville, Kentucky
  18. 1990TSIAWDTALON

    1990TSIAWDTALON Moderator

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    Independence, Kansas
    Ahhh. Yes I thought that it WAS running with it hardwired. So its NOT a fuel delivery problem.
    Cant get fuel had me thinking no fuel.
     
    My DSM:
    1992 Eagle Talon TSi AWD

    Street Build

    14b   automatic
    1990 Eagle Talon TSi AWD

    13.620 @ 108.460 MPH
    1990 Eagle Talon TSi AWD

    13.612 @ 107.760 MPH
    Loading...
  19. Jsmo123

    Jsmo123 Probationary Member

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    Joined Thursday
    Danville, Kentucky
    So we are thinking CAS? Rather not parts cannon any more. I dont know what else would prevent startup
     
  20. Jsmo123

    Jsmo123 Probationary Member

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    Danville, Kentucky
    New CAS did not fix it. Ordered IACV to see if thatll fix it. We pulled the plug by the throttle body and it ran for a second. We have fuel now.

    If anyone has any suggestions, please, shoot them my way.
     
    Last edited: May 18, 2018 at 7:28 AM
  21. steve

    steve DSM Wiseman

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    St. Charles, Illinois
    Just a reminder, the ECU controls the fuel pump with the MPI relay or the fuel pump relay on 2G's that that the two (MPI & Fuel). Diagnosing problems with the FP start by looking at that interface.

    Without the latest version of DSMLink there isn't any fuel pump prime when you turn the ignition on. The ECU starts the pump when it sees CAS signals and keeps it on until a few seconds has passed since the last CAS signal. The ECU does that by grounding the pin to the relay. Normally the relay coil resistance protects the ECU transistor from over-current damage but it's easy to pop it if it tries to pull 12v directly to ground. So you shouldn't expect the FP to start on until you start cranking the engine. If it doesn't you need to look at the relays again and see why.

    Too much fuel is as bad as none. There's a long list of car that wouldn't start because the CTS or it's wiring had failed. If you have a scanner or logger the first step after a compression test is to scan and make sure that the sensors are giving realistic values. The IAT and CTS sensors should be reading the current outdoor temp since the car hasn't been running. The battery voltage should be 12.2v or better. The IAC/ISC steps should be around 120 while waiting to start. You should see CAS and CKS signals once you engage the starter..

    There is a no start thread you should review and work through it's checklist.
     
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  22. Jsmo123

    Jsmo123 Probationary Member

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    Joined Thursday
    Danville, Kentucky
    I've studied the no-start thread and have been diagnosing this car with a guy who has built dsms for years for about 3 weeks.

    Here's the deal. We cranked the car with the plug by the throttle body in, I pulled the plug and it started (while cranking). (struggled to stay on then shut off) this leaves us to believe it's an air problem, it must not be getting proper air flow. I am just not sure where to look, logically it should run without the MAF, so not worried about that. This leaves me looking at the IAC or possibly TPS. Any other suggestions?
     
  23. steve

    steve DSM Wiseman

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    St. Charles, Illinois
    I doubt pulling the IAC/ISC connector off is telling you what you think it is.

    Is it consistently starting now with the IAC/ISC connector off? If you manually control the throttle does it stay running?

    I haven't tried unplugging the MAF to see how well the car runs in limp mode but it won't run at all if the MAF is plugged in but the IC pipe is disconnected as a reference. I understand they are different cars with different ECUs, I'm just suggesting you might have some invalid assumptions.
     
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  24. Jsmo123

    Jsmo123 Probationary Member

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    Danville, Kentucky
    I have not unplugged the IAC. There is a plug on a hose after my throttle body, pulled that out (giving the car more air) and it started for a second or two. Are you taking the assumption that its the CTS? I am open for advice and my goal is to start the car tonight.

    I was taking the guess it won't start because it's the IAC not allowing proper air flow. It almost starts, really wants to but fails.
     
    Last edited: May 18, 2018 at 8:19 AM
  25. Vegas smith

    Vegas smith Proven Member

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    Perhaps the BISS screw on the throttle body is turned in all the way not allowing enough air? Maybe try screwing that BISS screw out a bit as an option. I know my car acted exactly like this when I had then screw in all the way.
     
    My DSM:
    1993 Eagle Talon TSi AWD

    Street Build

    16g   manual
    1992 Eagle Talon TSi AWD (sold)

    16g   manual
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