No Injector pulse

Discussion in '1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-' started by hpcobra_347, Mar 28, 2007.


  1. hpcobra_347

    hpcobra_347 New Member

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    Greetings guys I have a major problem!! I bought a doner running, working 1995 wrecked Mustang GT and a 1996 V6 mustang planning a complete swap the whole 95 to the 96. I removed the motor tranny the whole nine yards. I swapped the whole dash board together with the harness. The ECM and ECM harness was also replaced together with the injector harness and tranny harness. The engine was rebuilt to a 347 stroker with 505hp at the fly wheel. Now for the problem: With the swap I have no injector pulse and the fuel pump is not turning on with the key forward. The engine turns over but no Injector pulse. I figured it was a ground, rechecked all connections on the harness but turned out ok. Replaced the ECM computer and the CCM with new ones but same problem no pulse and no fule pump turning on. Last night we changed the relay box harness because it was stock V6 but turned out worse now, the CCM is making a loud buzzing sound and engine wont turn over with key. WTF :bang: I have been working on this project for 2 months with no luck. There is electrical pulse coming out fron the MSD distributor and the MSD ignition coil running to the spark plugs therefore excluding the fact that it would be the TPI or TFI sensor. The fuel pump works with a just putting a direct 12v plug to it's wire excluding the probability it could be a faulty pump. I tried to tweeck the T4MO ECM computer with the tweecker, changed the injector slopes high and low from 19-26 to 42-51 with no luck same thing. The pulse from the distributor runs all the way to the ECM but comes out just as a constant weak power no pulse. We need a constant positive and negative for a pulse but noid light on injector harness is real weak. This is a 96 V6 and did not come out with a chip on the key so can't be a thing with the alarm either :bang: Don't know what else to try or do guys :shrug: Any help would be eternally appreciated guys. :SNSign: has always answered my questions just by reading but not this time thanks in advance guys :hail2: ..........
     
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  2. The Green GT

    The Green GT No 13 year olds are safe around me.

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    So you DO have fire?

    Im not sure what it is then. I know if there is no fire and no inj pulsing then its 95% the PIP.
     
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  3. HISSIN50

    HISSIN50 "How long does it take to get help in here?
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    If you have spark, your PIP is ok.

    FWIW, IIRC the V6 CCRM's are a different part number than the V8 modules.

    In such a case, I'd look at the injector side of things. Some theory: The injectors get constant Key-on power and the computer excites the injectors via a ground pulse. If your TPS signal return is reading ~3.7 volts or higher, the injectors shut off.

    How is the noid light signal weak? Those LED's tend to come on full bore or not at all.

    I'd want to ensure the 12 volt feed to your injectors is solid.

    I'd start with getting the CCRM issue resolved. You will want to run down the output voltages for all 5 relays (or the fuel pump and EEC relay at a minimum) to ensure you have proper function. Check the TPS return. Go from there.

    Good luck.
     
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  4. hpcobra_347

    hpcobra_347 New Member

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    Injector Pulse



    Ok guys yes we have fire or spark which the PIP sensor is OK. As for the CCRM it's the same from the V8 it was a complete swap and was working with the V8. We found out by accident that the TPS was at full blast at 6.18 volts which was placed at full throttle by mistake and corrected at 2.14 volts the correct position. We went to autozone, could not find the correct TPS for the 75mm Accufab so we ended up using one from some another vehicle , don't know which one and won't go lower than that. DOES ANYONE KNOW THE CORRECT TPS FOR THE 75MM ACCUFAB ON A 1995 MUSTANG ??? STOCK ONE WON'T FIT...

    I will check the 12 volt power to see if it's solid, have not checked for sure what voltage they have.

    Excuse me for being ignorant but what are the FWIW, IIRC ?

    Technially speaking the noid light is very weak, we have to shut all lights off to see how weak it really is. We checked my buddies 96 4.6 and that one really was at full blast !!

    How can I run down the voltages for all 5 relays? What 5 relays you mean the CCRM, Ignition module etc..
    THANKS FOR YOUR HELP IN ADVANCE GUYS !!!
     
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  5. HISSIN50

    HISSIN50 "How long does it take to get help in here?
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    FWIW = For What It's Worth.
    IIRC = If I Remember (or Recall) Correctly.

    The TPS stuff is strange. Your range should be 0-5 volts, +/- 10%. A baselined TPS reading in the 2 volt range would throw major computer codes as it ratchets.
    I can't help with the sensor and TB issue however. Others probably can.

    Good plan with checking the injector 12 volt feed. If it lights up a test light brightly but your noid light is dim, I'd have to wonder if there is an issue with the injector wiring (on the control/ground pathway).
     
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  6. hpcobra_347

    hpcobra_347 New Member

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    Injector pulse

    Found out today that Accufab never offered a throttle body for 1994-95 mustang! That's why the TPS would not fit and could not find one that would except for that high voltage one. Will try today with the stock throttle body see what happens. Do you think it's possible that the harness would get screwed up with the swap? Going to check the wiring and the power from and to the injectors. Any more ideas?? :nice:
     
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  7. hpcobra_347

    hpcobra_347 New Member

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    Update

    Well guys at last after 3years and 3moths in the planning and swapping we finally got the car to start. The thing with the injector pulse was a deal with the wiring. Since I swapped a 1995 GT engine to a 98v6 body the fuse box wiring is a bit diffrent than a 95 . Two ground wires were in empty slots in the plug connector which one went to the computer and the other to the fuel injector harness. Also the power or ignition for the fuel pump was in a dead slot. The schematics from Autozone really helped me out and your suggestions guys thanks alot. It's a 347 sounds beautiful put in about $8,000 just to the engine. Been working on the tunning thou and am running a little bit rich going to replace the MAF with a
    90mm and adjust the the A/F mixture see what happens. Anybody with a suggestion on a book or a good tutorial with FORMULAS and examples for the Tweeker ??:lol: No getting started but real FORMULAS !!!:nice:
     
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  8. mo_dingo

    mo_dingo Well-Known Member

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    Go to the tuning section. They have a lot of good info to get you up and tweecing. The best thing I have ever invested in was the innovative wideband O2 sensor. It just makes tuning so much more accurate; I stopped pulling my hair out!!!
    Scott
     
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