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.

I am Stumped?? Dollar to the first person who figures it out. UPDATE!!!

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by BlazerBoy, Sep 7, 2000.

  1. BlazerBoy

    BlazerBoy 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    639
    Likes Received:
    0
    Location:
    Chicago IL.
    o.k. guys I finally got my 87' TBI 350 motor rebuilt and installed, She starts right up, but doesnt run too well. At idle, the motor kinda surges, the RPM's go up and down. I thought of a open vacumn or bad vacumn line but havent found anything. After about a min or 2 or running my check engine light comes on. I have a code scanner, which shows 2 codes that continualy come up, which are, CODE 22, Throttle position sensor(tps) signal voltage is low during engine idle. And CODE 44, Lean exhaust indication, oxygen sensor voltage stays low after one or two minutes of engine run.
    Does anyone know how to start trouble shooting these. I also put a larger Compu cam in. I was told by a friend that I would have to get an adjustable fuel pressure regulator for my TBI, but I didnt know they made one. Anyways looking for ideas. Thanks sorry so long.

    BlazerBoy
    http://generalblueballs.coloradok5.com
     
  2. delta9blazer

    delta9blazer 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    1,646
    Likes Received:
    0
    Location:
    Northern California, over by 7-11
    Re: I am Stumped?? Dollar to the first person who figures it out.

    you might have to compensate the fuel delivery for the addition of the cam.
    if it had a carb, you'd tweak it a bit after installing a new stick, so i'm thinking the same thing has to be done with the computer.
    good luck.

    <font color=purple>delta9blazer</font color=purple>
     
  3. Re: I am Stumped?? Dollar to the first person who figures it out.

    Hane you checked the tps sensor to make sure its working corectly?Also sheck the vacume going to your map sensor.What model cam did you install?If its to big you might have to use an adjustable map sensor.
    Just a few ideas good luck.


    IF IT AINT BIG IT AINT BAD!!!!!!
     
  4. Kelboski

    Kelboski 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    306
    Likes Received:
    0
    Location:
    Mcdonough,Ga
    Re: I am Stumped?? Dollar to the first person who figures it out.

    before i had my 84, i had a 90 k5 w/ a new crate 350 w/tbi......it did the same exact thing...replaced the oxygen sensor, the electronic spark control module, and it kept on doing it........finally a mechanic did a diagnostic test, and it was a bad ground wire. the gm people that installed the engine did'nt connect the ground wire back, and the computer kept getting false readings and caused it to do the exacy same thing as yours is doing. the ground wire was attached...and the problems stopped....and then it would eat the pavement off the road!...the ground was attached to the fire wall somewhere.......hope this helps...Kelboski
     
  5. Re: I am Stumped?? Dollar to the first person who figures it out.

    Hey, I forgot about that my 88 did the same thing!!!It was a
    4.3 truck and I swaped in a 350,it was doing something close to that.Thanks for reminding me Kelboski.

    IF IT AINT BIG IT AINT BAD!!!!!!
     
  6. Emmettology 101

    Emmettology 101 3/4 ton status

    Joined:
    May 9, 2000
    Posts:
    8,126
    Likes Received:
    0
    Location:
    FL
    Re: I am Stumped?? Dollar to the first person who figures it out.

    About the best thing to use to find a vaccum leak iis to use Propane......

    Mike [​IMG]
    See <font color=green>EMMETT</font color=green> -&gt; http://emmett.coloradok5.com
     
  7. BlazerBoy

    BlazerBoy 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    639
    Likes Received:
    0
    Location:
    Chicago IL.
    Re: I am Stumped?? Dollar to the first person who figures it out.

    Hey you dont know where this ground is do you?? Here is the cam I put in. [​IMG]

    BlazerBoy
    http://generalblueballs.coloradok5.com
     
  8. BlazerBoy

    BlazerBoy 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    639
    Likes Received:
    0
    Location:
    Chicago IL.
  9. blazer72

    blazer72 1/2 ton status

    Joined:
    Apr 13, 2000
    Posts:
    939
    Likes Received:
    0
    Location:
    KCMO
    Re: I am Stumped?? Dollar to the first person who figures it out.

    You put in a lot of cam and its will take some work to get it to work if it ever will! You need more fuel so the first step is the new regulator. Most TBI's run about 15 psi running you may have to go to about 19 or 20 which will harm the injectors in the long run. Bigger injectors would be a better fix but the adj, regulator is still needed. For most TBI or TPI systems useing the stock Eprom you can't go much over the OEM cam.

    The 2nd problem is going to be getting the MAP to think its got more vacume then it does theres talk of an adj. map senser I would love to see this as it would help me in a few things I'm trying to do. For the most part comp need 15 inches of vac. at 800 rpm or so. Less than this and they hunt for idle.

    If it was me I would change to a smaller cam that was ground for TBI.

    I understand the jeep thing I drive a BLAZER!!

    Ken
     
  10. BlazerBoy

    BlazerBoy 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    639
    Likes Received:
    0
    Location:
    Chicago IL.
    Re: I am Stumped?? Dollar to the first person who figures it out.

    o.k. couple questions, where can i get an adjustable fuel pressure regualtor. And Where you kidding about the propane?? lol If not how would you go about doing that??? What is the best way to look for vacumn leaks?? Thanks guys

    BlazerBoy
    http://generalblueballs.coloradok5.com
     
  11. realsquash

    realsquash 1/2 ton status

    Joined:
    Jul 12, 2000
    Posts:
    778
    Likes Received:
    0
    Location:
    SE WI
    Re: I am Stumped?? Dollar to the first person who figures it out.

    OK, first thing... Forget about all the hi-po regulator and the map adjuster, etc. Your ground might be hosed. But you prolly have a problem with your TPS sensor. The correct way to troubleshoot this is to get a hold of a digital volt-meter and measure the setting at idle on your TPS. Or get a data logging setup hooked up (GM Dealer, Diacom, etc) and that will tell you the voltage the TPS is at at idle. You adjust this by loosening the 2 screws that hold it on an rotating it. Rotating it clockwise should raise the voltage and vise-versa. Even with a new TPS, you have to set the idle voltage. This should be in your shop-manual. If you read a goofy voltage, you need a new sensor. The code 44 might go away with the fixing of the TPS. Let me/us know what happens.

    Squash
    http://www.trailrunners4x4.org/users/realsquash
     
  12. realsquash

    realsquash 1/2 ton status

    Joined:
    Jul 12, 2000
    Posts:
    778
    Likes Received:
    0
    Location:
    SE WI
    Re: I am Stumped?? Dollar to the first person who figures it out.

    The Rochester injectors have proven to be able to hold up to 60 psi continuously w/o damage. In 1995 model year some chevy TBI trucks used around 50 psi from the factory vs. 13 psi previously.

    Squash
    http://www.trailrunners4x4.org/users/realsquash
     
  13. BlazerBoy

    BlazerBoy 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    639
    Likes Received:
    0
    Location:
    Chicago IL.
    Re: I am Stumped?? Dollar to the first person who figures it out.

    O.K. guys, I was able to remove the fuel pressure regulator and modify it to make it adjustable. No need to buy the adjustable ones guys. I adjusted the pressure and it ran well but had a high idle. I tested the TPS sensor and it said it was o.k. so I cleared the code. A friend borrowed a wicked scanner from work which tested all of my sensors and stuff all came out o.k. Except for the gear position switch on the column. It thought I was in drive when I was in park. So we adjusted that and now it runs beatiful. Thanks Guys.

    BlazerBoy
    http://generalblueballs.coloradok5.com
     
  14. blazer72

    blazer72 1/2 ton status

    Joined:
    Apr 13, 2000
    Posts:
    939
    Likes Received:
    0
    Location:
    KCMO
    Re: I am Stumped?? Dollar to the first person who figures it out.

    So tell us how you modifyed the regulator??? I have 2 trucks that could use this mod this weekend

    I understand the jeep thing I drive a BLAZER!!

    Ken
     
  15. BlazerBoy

    BlazerBoy 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    639
    Likes Received:
    0
    Location:
    Chicago IL.
    Re: I am Stumped?? Dollar to the first person who figures it out.

    Its real easy, if you take the top part of the TBI unit off the regulator come with it. On the bottom side of the regulator there is a brass adjusting screw, I think GM from the factory set the screw then melted the head of it or something. Because when you look at yours it will look like a bead of weld. Which is what I thought it was so I figured I would drill it out. I started drilling and it started spinning. So what you have to do it take a die grinder or something and make your self a slot in the head of that screw and then you can adjust it yourself. I am not sure if it has the range of adjustability that the aftermarket ones do, but it had enough for me. Good luck let me know if you dont understand. or need more info...

    BlazerBoy
    http://generalblueballs.coloradok5.com
     
  16. Emmettology 101

    Emmettology 101 3/4 ton status

    Joined:
    May 9, 2000
    Posts:
    8,126
    Likes Received:
    0
    Location:
    FL
    Re: I am Stumped?? Dollar to the first person who figures it out.

    Yes, you I have heard the best thing to use to find a vaccum leak is Propane. I have used carb cleaner, but haven't got to try propane yet.

    You just spray the propane or carbcleaner around all you vac lines and gaskets. If the idle goes way up then you found a leak. With the propane, I am not sure if the idle will go up or down. Sometimes it will even bog with the carb cleaner.

    I found some intake leaks like this and a few vaccuum leaks on my Probe this way.

    Mike [​IMG]
    See <font color=green>EMMETT</font color=green> -&gt; http://emmett.coloradok5.com
     
  17. realsquash

    realsquash 1/2 ton status

    Joined:
    Jul 12, 2000
    Posts:
    778
    Likes Received:
    0
    Location:
    SE WI
    Re: I am Stumped?? Dollar to the first person who figures it out.

    Why didn't you clear the code first? The adjustable FPR didn't fix the problem. Now you'll never know which one it was.

    Squash
    http://www.trailrunners4x4.org/users/realsquash
     

Share This Page