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Car not running after header install

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    Car not running after header install

    Replaced stock headers with SS headers and high flow cats. After install, test drive of about 10 miles - car ran well. Noticed a whistling sound at startup that ceased after 45-60 seconds and an exhaust leak during test drive. Traced whistling to secondary air pump hose that had come off and exhaust leak to one of the bungs. Started car, sounded good and parked for the night.

    Next day test drive, car lost power 1/2 mile from house. It would crank and run for 20-30 seconds before shutting off.
    Ordered scanner, had two codes, one was related to power supply, tested battery at 11.8 volts so swapped battery. Had read that low battery could affect fuel pump.

    New battery, car cranks and ran briefly then shuts off. Tried a couple more times with same results but car runs shorter amounts of time. Now car does not start. Turns over but does not start.

    Tried scanner and had several new codes. See attached.

    Researching the codes but would appreciate any advice from the forum. Thanks




    #2
    Might be time for a fuel pressure test, unfortunately the valve for testing is quite small and it is very likely you will not find a kit locally for rent that has the proper fitting. Check to make sure your fuel pump fuse is OK as well.
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      #3
      Fuel pump could have died. Turn on the ignition and listen for the fuel pump priming. If you have never replaced it, probably worth replacing as preventative maintenance anyway

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        #4
        One possibility is a blown fuse for the EWS. There is a lead from the EWS that runs through the fuse box (I think Fuse 14) and goes to the ECU. If that fuse is blown, the engine will crank but won't turn over.

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          #5
          Thanks for the advice. Will look into those areas this weekend.

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            #6
            One more thing to add to the list:

            Check the voltage on the battery, even though it's brand new. If it's low, charge it, turn on the car and make sure the alternator is charging it. If it's not being charged, then that would also explain why your old battery was reading low.
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              #7
              Originally posted by tarheel View Post
              New battery, car cranks and ran briefly then shuts off. Tried a couple more times with same results but car runs shorter amounts of time. Now car does not start. Turns over but does not start.
              Make sure the ignition ground cable is bolted to the head (near the oil drain banjo pipe to the oil pan). If not this can kill the fuel pump relay.

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                #8
                Originally posted by sapote View Post
                Make sure the ignition ground cable is bolted to the head (near the oil drain banjo pipe to the oil pan). If not this can kill the fuel pump relay.
                Good to know, I noticed the ignition ground was loose after the car stalled. I have since tightened it but it may have already damaged the relay. I’ll test the relay this weekend along with the other advice above. Thanks for the tip.

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                  #9
                  Make sure battery contacts are clean and tight! Use wire brush to clean off the battery terminals.

                  We don’t get much corrosion having battery in the trunk but worth checking since many aftermarket battery terminals are undersized.

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                    #10
                    Thanks for all the advice everyone.

                    Was able to work on the car today. Tried to start the car while my son listened for the fuel pump - couldn’t hear anything so we checked fuel pump fuses - looked ok.
                    So then we pulled the fuel pump relay and tried to do a continuity test.
                    This process is new to me and I had difficulty getting a diagram to explain the PIN numbers so did not have a lot of confidence in the results - I think the continuity test reflected a bad relay but decided to jump the two wires to the fuel pump with an inline fused wire just to make sure. As soon as I made contact, the fuel pump turned on so I think the relay is bad.

                    Ordered a new relay - hopefully that solves this issue.

                    Again, thanks for all the advice.

                    I also appreciate all the diy instructions on the forum and the time members take to document the process. I read the diy’s extensively before I start work - wouldn’t know where to start sometimes without the diy’s.

                    Will update after I get the new relay.

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                      #11
                      Originally posted by tarheel View Post
                      we pulled the fuel pump relay and tried to do a continuity test.
                      This process is new to me and I had difficulty getting a diagram to explain the PIN numbers so did not have a lot of confidence in the results - I.
                      For more info about the relay and testing, search for my posts on this couple months ago; someone here damaged the relay by forget to bolt down the ignition ground cable.

                      The control signal from the DME to the relay must been routed quite close to the ignition wires, and when the ignition ground was not grounded, the high voltage arcing coupled to and traveled to the semiconductor relay and damaged it. IF this relay is an old school coil and contacts then it should survive, but the transistors in the M3 pump relay cannot survive over hundreds of volts shock. But the trade off is semiconductor relay lasts longer as no wear and tear on the point contacts.
                      Last edited by sapote; 12-04-2021, 08:47 PM.

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                        #12
                        Originally posted by sapote View Post
                        For more info about the relay and testing, search for my posts on this couple months ago; someone here damaged the relay by forget to bolt down the ignition ground cable.

                        The control signal from the DME to the relay must been routed quite close to the ignition wires, and when the ignition ground was not grounded, the high voltage arcing coupled to and traveled to the semiconductor relay and damaged it. IF this relay is an old school coil and contacts then it should survive, but the transistors in the M3 pump relay cannot survive over hundreds of volts shock. But the trade off is semiconductor relay lasts longer as no wear and tear on the point contacts.
                        Found the thread - good info. Thanks for explaining the arcing that likely happened that damaged the relay.
                        The new relay arrived today, plugged it in and the car started up and ran like normal. Was not able to take on test drive today but let it idle for 2-3 minutes so I think that solved the issue.

                        Thanks again for all the advice.

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