Engine is Cutting Out

[waterloo88chev]

On my 5.7 carb Jimmy, I'm having a recurring problem that is rendering it not drivable. A few weeks ago I tried driving it for the first time at decent speeds and I found that I couldn't. The engine would would start popping and stop outputting power after just a small amount of acceleration. If I could manage to slowly get up to speed to change gears (automatic) it would, but it would do it again in the next gear. I got it home and found a disconnected vacuum hose, which I was sure was the culprit. Sure enough, it ran just fine after I reconnected it. A few days later the same problem came up, so I looked for a new vacuum hose problem. Sure enough I found another one that had vibrated loose, so I reconnected it. Problem is, it didn't fix it this time. I sputtered home and just went and tightened all of the vacuum line connections hoping to blindly fix the problem. Well the next time I drove it the engine could get to higher RPMs and everything just fine. But now it's idling like **** (only when in gear though). So AGAIN I look to the vacuum lines. I didn't find anything but I again retightened all the connections and put tape over any possible cracks. After that it's idling problem is fixed but is back to the same thing where the engine can't reach high enough RPMs.


Anyone have any ideas? I'm thinking about just replacing every single vacuum line on the engine. We had a few very very cold days here and I'm wondering if the cold didn't cause a few cracks that I'm simply not seeing in lines. Thanks in advance for any help.

[silverhairdeere]

hoses can have small pin holes in them the naked eye could never find , my advice replace all the lines including the brake booster one

shd

[03chevy]

like shd said replace all the lines. have you ever replaced them and how long ago?

[stumpuller454]

I would check your throttle body gasket aswell, could have dried up and cracked.

[leolkfrm]

sounds like some good advice for a starting point, you have determined the vac leaks cause the problems. Also if you have an EGR check it for vac leak and proper seating. line is cheap so lets us know if it's the solution

[waterloo88chev]

Well, I've replaced most of the vacuum lines. The ones that are hard plastic I didn't, but other than that I replaced everything. The problem is still there. I can rev it up as high as I want to in park or nuetral, but once it's in gear the throttle just gives and it's almost like a fast, repetitive back-fire with virtually no power to the wheels.

I see that post about the throttle body gasket, but I don't know what that is. Help?

[silverhairdeere]

try this , go to www.autozone.com put in your truck , go to trouble shooting and look up power loss , it will give you things to look at . it won't copy for me . let me know

shd

[waterloo88chev]

I'm afraid that link just throws an error...

[silverhairdeere]

still can't get it to work

shd

[gmctrucks]

How about www.rockauto.com or buy a can of starting fluid and spray it around your intake if you noticed if the idle changes look in the area where you applied the spray.