Jump to content

Fuel Injection Prob I Think.

tino12321

Recommended Posts

tino12321 New Member

tino12321

Posted
Posted

I have a 87 chevy with tbi 5.7 and 700r4. the truck idle fine but when you fether the throttle it starts missing and or dying until you push the rpms up to 1400 or so but it runs fine down the highway i have replaced the plus,wires,cap,fuel filters and still cannot stop the prob. Anybody have any input on how i can fix this prob.

95Sierra2500 Senior Enthusiast

95Sierra2500

Posted
Posted

I'd suggest the vacuum leak as well. There is also the possibility that your timing chain has stretched (presuming it's never been replaced) and is throwing off the timing at low speeds. This SHOULD cause a problem at all speeds, but that isn't necessarily the case.

 

I don't know that it's a fuel injection problem. Have you popped the air cleaner off and watched it spray? If you see nice solid cones of fuel spraying from both injectors, then those are fine.

  • 2 weeks later...
Zembonez Senior Enthusiast

Zembonez

Posted
Posted
Check the TBI base gasket for a leak, common problem with TBI's.

TBI (bionic carburetors) can get pretty crusty. While you are checking that gasket, might want to remove / flip the injector plate and see how dirty it looks.

Zembonez Senior Enthusiast

Zembonez

Posted
Posted
Check the TBI base gasket for a leak, common problem with TBI's.

TBI (bionic carburetors) can get pretty crusty. While you are checking that gasket, might want to remove / flip the injector plate and see how dirty it looks.

pennzoil29 Senior Enthusiast

pennzoil29

Posted
Posted
Check the TBI base gasket for a leak, common problem with TBI's.

TBI (bionic carburetors) can get pretty crusty. While you are checking that gasket, might want to remove / flip the injector plate and see how dirty it looks.

 

 

I guess +2 is in order here. :thumbs:

Squirrely Enthusiast

Squirrely

Posted
Posted

You can always spray a little carb cleaner around the base of the gasket. If there is a leak the engine will surge. This little trick works well with some of the vacuum hoses, etc.

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Latest Articles

  • Posts

    • newdude
      Transmission Temperature Hitting 220s

      By newdude · Posted

      It is working as designed.  NHT and non NHT trucks have the same exact transmission cooling setup.  NHT just gets a larger radiator.     The transmission cooler loop on these is as follows.     -Transmission out goes into an oil to water heat exchanger (item #1 in the first illustration below).  This exchanger has engine coolant opposite the transmission fluid and uses engine coolant to warm and then regulate the transmission fluid temperature when its in the operating window.   - From the cooler it goes to a thermal bypass valve (item #11 in the 2nd illustration below).  If the ATF has not reached the temp to open the bypass (194F), it loops back.   - When it reaches 194F, the thermostat opens and ATF then flows out to the oil to air auxiliary cooler (item #17 in the 2nd illustration) at the front of the truck.  From there it goes back to the transmission.     Your only fix would be to swap for the PPE thermal bypass delete block which will open the loop to the aux cooler all the time.  It will STILL run warm, probably 170-200F, but that's as low as you'll get it as its still flowing through the oil to water exchanger.      
    • Grumpy Bear
      Slate Electric Truck

      By Grumpy Bear · Posted

      Most say the oil temperature needs to above the boiling point of water to rid it of moisture and long enough to dry it. Many think that is about a hour at 212 F or more. Those people have never line dried cloths in a Midwest winter. Leave a pan of water sitting on the counter and eventually it all evaporates. So heat drives the time it takes. Water in oil under 175 F, the Nitration initiation temperature, is a minimum then for temperature and samples I've done that use Karl Fisher method say about a hour (in a healthy well tuned motor) over 175 F will dry it to under 800 ppm. Low enough to not be much of a factor. Motors with weak rings will take longer and the colder the air temperature the longer it takes.   On a cold motor there is also the condensation temperature. Blowby gases that contain moisture are subject to that cold cylinder wall, like sweat on a glass of ice tea. But also subject to the Law of Partial Pressures. Wear studies by GM and the DOD  indicate wear is a real issue below 85 F and a concern to 140 F but doesn't become a minimal factor until about 160 F. You know this intuitively when you see water vapor exit the exhaust pipe until the system gets above the dew point. It isn't magic, it's physics and it fascinates me. I know you didn't ask but....I over share sometimes. 😉    You keep the Camaro's high and tight.  
    • asilverblazer
      Slate Electric Truck

      By asilverblazer · Posted

      Move further away.   Benefit of living out - none of our cars get short cycled, plenty of warm up time.   Curious how much time/temperature it takes to drive moisture/condensation out of the engine?
    • diyer2
      Transmission Temperature Hitting 220s

      By diyer2 · Posted

      Switch a a 100% synthetic trans fluid, Amsoil works for me.
    • DustMcGrath
      Transmission Temperature Hitting 220s

      By DustMcGrath · Posted

      First of all sorry, I know there are a ton of transmission temperature threads...   My truck is a 2025 LZ0 High (10l89 10-speed) High Country with NHT max trailering package. The NHT package is supposed to have "enhanced cooling."   Normally the trans temp sits around 200. It seems like with any real stress it quickly jumps into the 220s (for example climbing a grade unloaded at lower speeds). I haven't towed much with this truck, but I'm concerned if it gets this hot unloaded.    I've tried a few different things to keep the temps down (tow/haul mode, sport mode, low range when that makes sense) and nothing seems to affect it.    I'm curious if others are the same behavior or if anyone has found techniques to keep the temps down. It seems like it just can't handle reduced airflow at lower speeds, even with relatively light loading.    Thanks!      

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...