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Engine Prob w/ Video

Discussion in 'The Garage' started by PeteH, Jun 20, 2006.

  1. PeteH

    PeteH 1/2 ton status

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    so i just put an engine and tpi in my truck and now it just doesnt have uummph(overrevvs when i try to go, but it will cruise around 15-20) it could be so many factors... heres a video..
    click on the photo to see video.[​IMG][/IMG]



    heres are my specs:
    (2004) 350 crate motor(it drove/performed well in another truck right before i took it out and put it in my truck.)
    tpi parts here and there mainly 86-87
    90-92 camaro harness with computer reprogrammed
    th350
    torque converter summit #g2700 i think has 1800 stall (tech guy said it would be fine)

    theres are no trouble codes before or after driving it around the block(15+ min.running).
    i know i have an exhaust leak.
    i think i have it idling a little too high
    not sure if there is the sound of a nonfiring cylinder
    it sounds like the iac is always open so that could be it right there.
    I couldnt see/hear any vacuum leaks on my lines.
    i then replaced the modulator, still wierd
    then replaced the vacuum lines coming off steel mod lines with even more robust fuel lines(same i.d. but bigger o.d.)and still wierd
    I originally had it hooked up so that the modulator vacuum was tied into the throttle body(underneath) but that didnt work, so i tied it into the brake booster line as a last resort.

    my torq. cnvtr is in right(had to pull it forward to meet up with flex plate) and put fluid in it before hand.
    i have the right amount of fluids in everything..tranny motor and transfercase(except for coolant.. theres still an air bubble in the system i have to address)
    i dont think it's the tranny. my truck rode fine before the swap. I'm still pointing to vacuum leak.
    i guess i should check for compression(would a broken piston ring make it have no power?)
    tps is set
    timing is set
    fuel pressure is set
    i have more than half a tank.
    i'm still new to engine swaps in general(this was my first:pimp: ) so any info would help.
     
  2. beastofablaze

    beastofablaze 1/2 ton status

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    sounded fine to me... your symptoms sound alot like your computer getting used to the coolant temp sensor. It needs time to work alot of the little problems out... my rig wouldn't even start with the new motor but after a week or so it would fire up like clockwork just needs more time running.

    If it was a vacuum leak it would be surging or revving up and down by itself. From what I heard I don't think a vacuum leak is your problem. Could even be you throttle cable or tps.
     
  3. PeteH

    PeteH 1/2 ton status

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    the reason i was thinking it was a vacuum leak was beacuse of the shifting probs. hey where in cali do you live?
     
  4. Russell

    Russell LB7 Tahoe Status Premium Member GMOTM Winner

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    Is your transmission slipping off idle? My 89's TBI engine ran great (less some knocking, but that is besides the point!) but the transmission slipped really bad all the time.

    Your engine seems to run pretty good -- better than mine does, thats for sure! Try and rev mine up, and you get a nice backfire (retarded timing, knock sensor is no good and retarding my timing big time :( )
     
  5. hack500

    hack500 1/2 ton status

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    what happens at higher speeds? and what rpm is 'overrevving'?

    is the kickdown cable adjusted correctly?
     
  6. PeteH

    PeteH 1/2 ton status

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    i didnt really think about letting the comp learn..didnt know itd take a week to learn out bugs.hmmm.. it does start up everytime, but i guess i should be letting it learn like you said. it makes sense.

    and the thing about the vac surging makes sense too.


    it only gets up to about 20 but thats it reving up around 4k(tach is broken right now so i'm guestimating)

    as for the kickdown cable: its about or a little less then a guitar string tight. but when the butterflies are closed it kind of loose. its a lokar cable.
     
  7. SUPER'BURB

    SUPER'BURB 1/2 ton status

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    If the motor is starting, revvvvvving and sounds good I would start looking at the tranny.

    Good luck.
     
  8. PeteH

    PeteH 1/2 ton status

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    i need all the luck i can get.:D
     
  9. SUPER'BURB

    SUPER'BURB 1/2 ton status

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    Off topic but where in S.J. are you?

    I spend alot of time in south S.J. down by Bernal.
     
  10. 96RAM85CHEVY

    96RAM85CHEVY Registered Member

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    your IAC valve might be sticky,or getting unwanted pulses from the ECM. throw a voltmeter on it ,and check it while at idle and revving,and while driving if you can,see if the volts go up smooth and steady with no flucuations or huge gaps[this is on the TPS} BTW,are you running speed density,or maf?

    also which ECM are you running? 870/165/730?

    870 being 85 only
    165 being 86-89
    730 being 90-92

    have datalogging software? and an ALDL port hookedup? email me transam406sbc@yahoo.com and ill send ya the software i use for my transam.
     
  11. PeteH

    PeteH 1/2 ton status

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    wait a miniute...do you work at speed merchant?!

    i'm in campbell/saratoga area, kinda where ryanb lives
     
  12. PeteH

    PeteH 1/2 ton status

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    tps voltage is smooth, comp is a 730. and that being said its speed density. i dont have a scanner or anyway of scanning it with my laptop. i should check though exactly how to do it with the lap top. i know theres free programs floating around like winaldl or something. as for the iac sticking i'll check again.
     
  13. SUPER'BURB

    SUPER'BURB 1/2 ton status

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    No I work up in San Leandro managing a sheet metal shop.

    I used to go to the car show in campbell at that burger place on the corner of Bascom and Union. I think it's called Happy Days
     
  14. PeteH

    PeteH 1/2 ton status

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    dont know if its still there but i know where your talking about.:D
     
  15. PeteH

    PeteH 1/2 ton status

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    so my timing was kinda off. the engine sounds even better and catches better. if you watch the video you can see that the engine was sluggish and when i opened up the throttle it took a while to kick in.

    my timing marks seem to be off on my balancer and cover. i need to find exact top dead center(instead of just checking the marks and seeing the rockers both loose)by checking the actual piston.
    I did time it with the light before, but i redid it without the light and timing marks. again it seems as though the marks are off but does indead run better.

    i feel more power to the ground, so tomr i will give her a check and fine tune it. hope the luck is still around.
     
  16. Russell

    Russell LB7 Tahoe Status Premium Member GMOTM Winner

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    Sounds more like a prom type thing, or maybe even a bad knock sensor like myself. Chances are your timing indicator is just fine... By tricking the ECM by adding extra initial timing it doesn't know about is typically considered a no-no with it being so easy to change the timing in the prom. It could cause detonation issues in Power Enrichment mode, and possibly induce the bad gas protocol, which basically hugely retards your timing until you restart the engine.

    And yes, I did notice that your throttle response was pretty sluggish. Mine snaps up to 5000 rpm in an instant, even with it backfiring & having no knock sensor hooked up. I think your best bet is to get an ALDL cable, laptop with a serial port, and TunerPro RT to do some datalogging, and see exactly what the ECM is seeing. You can then adjust everything on the engine such as the IAC adjustment, TPS, etc properly.

    I went to adjust my prom, and it appears my AT29C256 EPROM chip has failed :( I can read it, but can neither erase, or program it :(

    Sucks, I soldered the thing in, and now I've got to find some way to get it out without ruining my memcal :(
     
  17. PeteH

    PeteH 1/2 ton status

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    interesting...thinking that tomr i'll see if i can scrounge up enough pennies and manage to read from the aldl.

    sucks bout you the prom chip. as for the solder you could always get one of those suction things.... its just a little marker sized device that has a spring on it and you push down a button. heat up the solder till it pools and undo the button on the device acts as a vacuum.the solder sucks up right away. sorry i suck at explaining..but anyways..theyre cheap and really cool if you mess up soldering on a motherboard.(i'm a nerd)
     
  18. PeteH

    PeteH 1/2 ton status

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    sc..i think your right about me tricking the comp. i started to drive my truck and either it was compensating for what i did or i just have no gas. but once i get some more gas i'll try the whole aldl laptop thing.
     
  19. PeteH

    PeteH 1/2 ton status

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    ok i need some more help with the aldl cable. i've seen a couple of wiring diagrams but i just dont know what will work best with my truck. does it even matter? tpi 90-92 '730 comp speed density
     
  20. Russell

    Russell LB7 Tahoe Status Premium Member GMOTM Winner

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    I tried making one but it didn't work at all. I wound up buying a cable off ebay for 20 bucks, and calling it a day :)

    However, whatever you buy, make sure that you can install the cable without it putting any resistance into the diagnostic (white / black wire) wire. Unlike a `165 ECM, the `7730 doesn't need any resistance to start sending data. It just forces the ECM to idle at 1000 rpm, and changes a few other things, giving you an innacurate look at what all is going on.
     

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