Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Is my alternator going bad? could my timing be off?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by BayouBlazer88, Sep 24, 2003.

  1. BayouBlazer88

    BayouBlazer88 1/2 ton status

    Joined:
    Jul 31, 2002
    Posts:
    353
    Likes Received:
    0
    Location:
    Lafayette, LA
    I just got my 88 blazer out of the shop because my stock computer chip wasn't working well with the new vortec heads. The guy put in a hypertec thermomaster chip and said that it was much better. Well, I drive home and everything is fine and dandy. Then when I try to start it up again after sitting for about an hour, it dies after about 5 secs. I keep restarting it until finally it runs. Then I put it in reverse and the minute I let off the gas to switch back into drive, it dies again. After a while it finally stays. One thing I noticed while it was running was that the voltmeter needle kept swaying between 13 volts and 17 volts and never stayed constant. Also, I have the timing advanced about 4 degrees for the vortec heads. Also, I've got a 180 thermostat in there right now and hypertec recommends a 160. So could a bad alternator make a tbi motor run bad? or is it the timing or the thermostat? I'll run to autozone and pick up a 160 thermostat and bring the alternator in to have it tested. Thanks for the help.
     
  2. big d

    big d 1/2 ton status

    Joined:
    Oct 24, 2001
    Posts:
    1,236
    Likes Received:
    0
    Location:
    illinois
    i dont believe yur mods has anything to do with the volts. i think its yur alternator or a battery electrical problem. id also check yur battery cables for damage and proper grounding. good luck. /forums/images/graemlins/thumb.gif /forums/images/graemlins/k5.gif /forums/images/graemlins/usaflag.gif
     
  3. BayouBlazer88

    BayouBlazer88 1/2 ton status

    Joined:
    Jul 31, 2002
    Posts:
    353
    Likes Received:
    0
    Location:
    Lafayette, LA
    Forgot to mention, this is an 88' blazer converted to serpentine belt from a 91' suburban. The alternator is from the burban as well so I don't know how old or abused it is. One thing I noticed on the autozone website was that the 89-91 alternators are 105 amp while the 88's are like 85. Could the increased current hurt the computer in any way? Also, when I was trying to start it sometimes I would hear a whine coming from behind the glovebox.
     
  4. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,975
    Likes Received:
    189
    Location:
    Roy WA
    Check that your gauge is reading correctly before replacing an alternator. It probably IS correct, but when someones been messing with the truck, the chances of wiring connections getting disturbed is very possible.

    I don't know much about the "thermomaster" chips, but if it's anything like their other chips, they are piles of garbage that advance the timing so much you end up running premium gas, and thats about it. Vortec heads don't NEED that additional timing, at least not the same as a TBI headed truck would.

    I certainly hope he didn't install the chip for your truck with the original motor.
     
  5. BayouBlazer88

    BayouBlazer88 1/2 ton status

    Joined:
    Jul 31, 2002
    Posts:
    353
    Likes Received:
    0
    Location:
    Lafayette, LA
    The guy at the shop said they had someone working for them who had like an 87 truck and did the vortec head swap like me and that when they installed the new chip, it ran fine. So he recommended I do the same and so I did. Now correct me if I'm wrong, but when an alternator is going bad, isnt the volt meter supposed to show a low reading rather than one that keeps swaying between 13 and 17 volts? And once again, can a bad alternator make the truck run bad since it's fuel injection?
     
  6. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,975
    Likes Received:
    189
    Location:
    Roy WA
    Well first off, I can't imagine a shop telling you they don't know what they are doing. I can't say for sure what that hypertech chip is doing, but I'll bet you haven't hooked a scanner up to it and checked how much knock is being detected. Am I correct? Ask anyone you like that builds engines what correct timing is for all RPM ranges, and at least part of the answer will be "every engine combination will be different".

    To think that a mass produced chip designed for multiple applications can even be close to optimal is incorrect. Don't take this as a personal flame, but do some research on this. Tuning an injected vehicle can take hundreds of PROM's to get right, and thats for ONE particualr vehicle/engine combo.

    Enough of that. You've already spent the money, not much to do about it.

    Never driven an injected vehicle that I knew had an alternator problem. I would assume varying voltage would be a likely cause of all sorts of problems. The alternator can fail in a few ways, and overcharging (or random output) is one of them.

    Like I said, hook up a voltmeter to the thing before replacing the alternator, but don't wait. The excess output isn't doing you any good, if that is what is actually happening.
     
  7. BayouBlazer88

    BayouBlazer88 1/2 ton status

    Joined:
    Jul 31, 2002
    Posts:
    353
    Likes Received:
    0
    Location:
    Lafayette, LA
    well in that case I'll try and get my money back for the chip. I read the instructions on the chip and in big bold letters it says "REQUIRES 93 OCTANE OR HIGHER GAS TO RUN CORRECTLY". and the mechanic didn't even mention anything about gas grade. I still have the old 87octane in the tank from the old engine so that could be part of the problem.
    Anyway, do you have any recommendations for custom burned chips? I hear turbocity makes them.
    If that doesn't work, then I'm letting this thing roll of a bridge and collecting the insurance. /forums/images/graemlins/eek.gif /forums/images/graemlins/eek.gif /forums/images/graemlins/eek.gif
     
  8. BowtieBlazer

    BowtieBlazer 1/2 ton status

    Joined:
    Jul 15, 2001
    Posts:
    2,462
    Likes Received:
    0
    Location:
    Baton Rouge, Louisiana
    when you decide to lay the keys down bring it to me, i'll take it...
     
  9. KRAZIE87K5

    KRAZIE87K5 1/2 ton status

    Joined:
    Feb 23, 2001
    Posts:
    3,369
    Likes Received:
    0
    Location:
    Chicago, IL
    Where to start... AH YES...

    [ QUOTE ]
    I still have the old 87octane in the tank from the old engine so that could be part of the problem

    [/ QUOTE ]

    Heh... last time I checked, 87 octane running in a motor that claims to need 93 because of a chip swap will not make your voltage jump around between 13-17v! /forums/images/graemlins/grin.gif Of course I've been known to be wrong now and then...

    But seriously. EVEN IF the chip wanted 93 due to timing advances, the knock sensor will drop the timing right back where it belongs since it drops timing incrementally until pinging (detonation) ceases.

    Figure out what is happening with that excessive output... or else you will fry your ECM in very short order.

    Where does it (the chip MFG) suggest to have base timing set? I'd guess its not a stock setting... and even 4* probably isn't correct.

    Second... are you getting any SES lights? What codes is it throwing? Slap a paper clip in that ALDL, and see what the SES tells you. (if you need help with this feel free to PM me)

    FINALLY, (phew!) I'd suggest telling that "mechanic" to take his chip back and give you a full refund. I run vortec heads on my 89 Burb... and I run a STOCK CHIP and ECM. Base timing is set at 8* just in case you are wondering... /forums/images/graemlins/thumb.gif

    -Dan
     
  10. BayouBlazer88

    BayouBlazer88 1/2 ton status

    Joined:
    Jul 31, 2002
    Posts:
    353
    Likes Received:
    0
    Location:
    Lafayette, LA
    Ok, well I fixed the voltmeter problem, just a corroded connection and when I cleaned it off real good and started it up again, it read fine (about 14 volts).
    Now as far as the timing goes, I had it set at 4* BTDC when the mechanic put everything in but I set it back to 0 thinking that the chip was not intended to run at 4* but when I changed the timing, it changed nothing. And I looked on the chip instructions and they say nothing about timing so I'm assuming they want it to be at 0.
    The SES light hasn't come on yet but I have a tool to stick in there and I'll check to see if any codes are coming out.
    Now with your burban, did you use the GMPP vortec-style intake for tbi? because that's what I've got on mine. does it run well? what grade gas do you use? I'll try putting the stock chip back in and setting the timing to 8* BTDC and see what happens. Thanks for the help.
     
  11. KRAZIE87K5

    KRAZIE87K5 1/2 ton status

    Joined:
    Feb 23, 2001
    Posts:
    3,369
    Likes Received:
    0
    Location:
    Chicago, IL
    [ QUOTE ]
    Now with your burban, did you use the GMPP vortec-style intake for tbi? because that's what I've got on mine. does it run well? what grade gas do you use? I'll try putting the stock chip back in and setting the timing to 8* BTDC and see what happens. Thanks for the help.

    [/ QUOTE ]

    On my Burb I run the Edelbrock Performer intake... that GMPP intake was too rich for my blood! Does it run well? Um... YES. I love it. It does good enuf towing (despite the corvette L98 roller cam) and for a 6500-7000# 3/4 truck, it sure skoots on the street too! And oh yea, I run 87 everywhere I go... even towing.

    When you set your timing, be sure not to forget the barrel plug w/the brown wire. If you don't unplug that... its going to give you all sorts of grief.

    Drop the stock chip back in the ECM, and set the timing. If its still dying... check vacuum.

    Let us know how it goes! /forums/images/graemlins/thumb.gif

    -Dan
     
  12. BayouBlazer88

    BayouBlazer88 1/2 ton status

    Joined:
    Jul 31, 2002
    Posts:
    353
    Likes Received:
    0
    Location:
    Lafayette, LA
    Since when does edelbrock make a vortec intake for tbi? Are you still running the tbi? because the GMPP intake was the only one I could find that accepted tbi and vortec heads. and yes I always unplug the little tan wire before I mess with the timing.
     
  13. KRAZIE87K5

    KRAZIE87K5 1/2 ton status

    Joined:
    Feb 23, 2001
    Posts:
    3,369
    Likes Received:
    0
    Location:
    Chicago, IL
    Yes, edelbrock makes a Vortec intake for the TBI. I can't find it on their site right now... but you CAN find one perched between those vortec heads under my hood...

    BTW, no provision for EGR either... /forums/images/graemlins/tongue.gif

    -Dan
     
  14. BayouBlazer88

    BayouBlazer88 1/2 ton status

    Joined:
    Jul 31, 2002
    Posts:
    353
    Likes Received:
    0
    Location:
    Lafayette, LA
    ok I just finished replacing the original chip and I'm about to start it up and adjust the timing to 8* BTDC. I don't know if this makes a difference but this block has been bored out .03" and it has been decked, hence the compression will be higher than just replacing heads. anyway, I'll go start her up and let you know what happens.


    -Update, she's running as we speak but running like crap. Idle is still really loopy and if you rev it up, as soon as you let off the gas, she almost dies. So does this sound like a vacuum leak? It runs the same as it did with the new chip so at least I can return the chip and get some money back.
     
  15. KRAZIE87K5

    KRAZIE87K5 1/2 ton status

    Joined:
    Feb 23, 2001
    Posts:
    3,369
    Likes Received:
    0
    Location:
    Chicago, IL
    That slight change in CR should have very little effect...
     
  16. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,975
    Likes Received:
    189
    Location:
    Roy WA
    What's the calculated compression ratio on your rig now?

    I don't know what the stock TBI heads were, but it appears that with the Vortecs 64CC heads, most engines with 72CC heads are put into the 9:1+ range. That's not too much with the Vortecs, but with the block being bored, and shaving, plus I'm guessing head gasket change (what thickness? Not that .015" one right?) you *might* be running a bit more than you think.

    Doubt it's causing your problems of course, but if she's idling bad, it's more than likely some kind of ignition or vacuum problem. Could always be the IAC, or something along those lines, but vacuum leaks and such just seem to be a more common culprit with poor running.
     
  17. KRAZIE87K5

    KRAZIE87K5 1/2 ton status

    Joined:
    Feb 23, 2001
    Posts:
    3,369
    Likes Received:
    0
    Location:
    Chicago, IL
    Um... silly question... but *I've heard* /forums/images/graemlins/ignore.gif that if you install the wrong plugs in the Vortec heads, the motor will run like junk and die all the time. Just a hunch. If you have the right plugs, you would remember paying like $5.99 ea for the correct AC Delco plugs... its a longer design for the Vortec heads than the std. TBI plugs.

    Just a thought... /forums/images/graemlins/blush.gif /forums/images/graemlins/thumb.gif

    -Dan
     
  18. hardcore71

    hardcore71 Registered Member

    Joined:
    Nov 21, 2002
    Posts:
    86
    Likes Received:
    0
    Location:
    Weare NH
    A quick comment on plugs for vortec heads. I can't remember the part # right now but plugs for a cadillac sedan deville with a 4.5 liter are the same as original vortec plugs just not platinum.
     
  19. KRAZIE87K5

    KRAZIE87K5 1/2 ton status

    Joined:
    Feb 23, 2001
    Posts:
    3,369
    Likes Received:
    0
    Location:
    Chicago, IL
    [ QUOTE ]
    A quick comment on plugs for vortec heads. I can't remember the part # right now but plugs for a cadillac sedan deville with a 4.5 liter are the same as original vortec plugs just not platinum.

    [/ QUOTE ]

    Yea... I bought the Bosch equivilent to the ACDelco part from AZ for like $3ea.!

    -Dan
     
  20. BayouBlazer88

    BayouBlazer88 1/2 ton status

    Joined:
    Jul 31, 2002
    Posts:
    353
    Likes Received:
    0
    Location:
    Lafayette, LA
    I never thought of that. I thought the vortecs used the same plugs so I just got some AC Delco plugs for an 88' blazer for like $1.50 a peice. Now when I go to Autozone what vehicle do I put into the computer to get the correct plugs? 96'-up vortec trucks with a 350? that would be my guess. Now what's the big difference between the 2 plugs? And a plug that's too short really cause this much pain and suffering? Anyway, thanks for the reply. Now I have one more thing to tell my stumped mechanic.
     

Share This Page