Where does that hose go?

[deedledoo]

Hey guys,

my sierra was a longer time in the workshop, cause one day it wasnt starting anymore. they replaced the fuel pump and fuel filter apperantly and it started once again.. kinda.. but, whenever i hit the pedal, the car is stuttering and after some km, im unable to drive anymore and i have to shut it down for few min, and then it drives with less stuttering again, and it doesnt go over 80 kmh, cant even drive uphill. so i checked at some point the MAP sensor, which showed me a reading of 2.5V, despite throttling. I got a new one yesterday and it didnt change anything, now im going soon to test the Volt and see if it was the sensors fault too. Maybe someone can help me out there, but my question for now is, i noticed that plug, which had a really worn rubber hose left like 0.3cm's, but i cant find anything, to where it comes or goes to..

i havent touched the sierra before the workshop, since it wasnt my car, but when i started to overhaul and clean the engine, i noticed that.

whenever i put my finger on it, the engine runs quieter, (like it should with good idle), but revs up in idle to 1300ish!?

im more or less of a amateur, so dont wonder, if that is a real basic thing ^^

i cant afford to get it back into the workshop, so i gotta fix that myself.

i'd really appreciate if someone could give me advice.

BR,

doodledee no wait.. deedledoo 😄

[deedledoo]

So with the new MAP sensor its the same, 2,5v. No change, if throttling or not. does that mean its a faulty control unit?

[Paulkp]

That is not the vacuum to the fuel pressure regulator, is it ?

[Fishysw2]

I had this on mine and exhaust smells came into the cabin so it may be something with the fuel lines

[TomsFocus]

Is there a charcoal cannister on that age Sierra? 

Whatever it was for, I wouldn't leave it open as that'll be causing problems in itself.  I'd block it off with a short piece of pipe and a screw for now.

[Paulkp]

I have scoured my Haynes 4cyl Sierra '82 -'93 Manual, and cannot find anything useful. It does state, if it has a Cat, then it should have a Canister etc

[Paulkp]

Only other sugestion is post on XROC

http://www.xrstyle.co.uk/forums/index.php

[deedledoo]

On 11/1/2021 at 10:24 PM, Paulkp said:

That is not the vacuum to the fuel pressure regulator, is it ?

There are to openings, one is connected with the fuel p reg and the other one is or was connected somewhere apperantly, since there was that tiny brittle rubberhose left. when i block it, the engine goes to good idle while leaving it open it stays higher.

4 hours ago, Fishysw2 said:

I had this on mine and exhaust smells came into the cabin so it may be something with the fuel lines

I dont have any exhaust smells, although i wasnt really paying attention. i guess i would have noticed.

4 hours ago, TomsFocus said:

Is there a charcoal cannister on that age Sierra? 

Whatever it was for, I wouldn't leave it open as that'll be causing problems in itself.  I'd block it off with a short piece of pipe and a screw for now.

Yes there is and blocking it off didnt change anything, it still runs poorly if i accelerate

1 hour ago, Paulkp said:

Only other sugestion is post on XROC

http://www.xrstyle.co.uk/forums/index.php

ok i will try to find help there too

 

can anyone let me know, if the signal voltage should change when testing?

or is it some kind of rare special thing version were it doenst apply... :/

because if it should change, as i believe, this might be the problem from there going on

if its constantly giving 2.5v signal and doesnt change according to the throttle level, theres a problem with the fuel/air ratio..no?!

if there was a fuel pressure problem or something like that, the sensor should still change...

im so confused ;/

i envy anyone having a friend or family with deeper knowhow 

Thanks for the replies so far. :)