Need a vacuum hose diagram for an 88 chevy stepside w/ 350 5.7 liter throttle body injected engine

In the link

https://www.google.com/search?q=5.7+liter+engine+chevy+1995+chevy+350+tbi+vacuum+line+diagram

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Vacuum Diagrams - AutoZone

www.autozone.com/repairinfo/.../repairGuideContent.jsp?page...

AutoZoneGM Chevy Mid-Size Cars 1964-1988 Repair Guide ... Fig. Fig. 4: 1971 V8 enginevacuum hoses ... Fig. Fig. 12: 1976 350 V8 engine-4bbl with EFE and AIR injection systems .... Fig. Fig. 52: 1980 5.7L V8 engine-automatic transmission federal. images for 1988 Chevy V8 5.7L 350 4bbl vacuum ...

The 1995 350 is a "Vortec 5.7" motor if I remember correctly.You will have to get a throttle body and intake manifold for an older 5.7 liter(early 90's?).The Vortec engines are a sequential multiport injection setup(totally different).

If you're near a large Library most libraries have auto repair manuals specific to wiring and specific to vacuum diagrams that would be the first place to check

Sorry I don't have the diagram, but I do have a diagram of the engine and component locations. Your vacuum system is fairly simple. You have a MAP sensor attached to the air cleaner. I have pasted a picture below. It has one electrical connector and one vacuum hose that goes to the intake manifold or the throttle body.
Behind the right headlight is your evap canister. This will have a hose or line running to the fuel tank. Then it will have another hose going to the purge valve. The purge valve should be close by and it has a connector plus another hose that goes to the intake manifold.
Then you have the PCV hose that goes from the PCV valve in the valve cover to the air cleaner or intake manifold. I think yours just has a hose from the air cleaner and the rest is internal.
There is one more vacuum hose, and that is the bog one that goes from the intake manifold (or throttle body--looks to me like there are a couple of vacuum ports on the back side of the throttle body, and there may be a "T" on one of the hoses) to the brake booster. It this one was off, the engine would not run, as the vacuum draw is large. Please let me know if you cannot figure it out from these instructions and provide a picture, if you can.

MAP sensor:


purge valve:

There is usually only one vacuum connection on a turbo 350. It connects to the modulator valve on the side of the transmission. This valve uses engine vacuum to determine transmission shift points. The other end usually connects to a direct engine vacuum source. A "direct source" is a hose connection on the throttle body that has a vacuum signal available at idle. If it doesn't, then it's considered a "ported source".I have had some experience with the chevy blazer/gmc jimmy series, both the early large body models and the small body versions. The stalling when put into gear complaint is most likely caused by a bad intake gasket which is common on the older versions with the small block V8 motors. The newer versions with the vortek motors also had allot of trouble with throttle body gaskets. If these problems have not already been addressed, then there's a good chance that it will take care of the problem. Other possible sources of vacuum leaks are the pcv hose that is hard and brittle. Check the hose out carefully, especially the side that normally faces the engine. Check the throttle body bolts (carburetor bolts) for tightness. I hope that this information is helpful to you. Thank you for using Fixya.com.

Check ALL vacuum hoses as your truck is getting older and rubber components may be breaking down.ALL sensors need good connections,electrical and where needed,vacuum to send correct data to the computer.
Has the throttle body been cleaned lately?
Don't overlook regular maintenance,plugs,wires etc.

it may not be a vacumn leak from a line,check the throttle shaft for movement,for example,i had a 89 1 ton 350 and my throttle shaft was moving around a lot and in order to keep it from idling high,i had to kick the throttle pedal.But also check the idle air control valve,which is the round sensor on the side of the throttle body.

any body parts from 1988-1998 will interchange.(except box parts stepside vs fleetside Grilles and head light/front signal lights differ from year to year but an newer grille can be put on an older truck as long as both trucks have the same headlights) As for the complete engine you can use any throttle body engine from another truck But you are best to keep the computer or at least the chip with the corresponding engine. the computer can be found behind the glove box. I believe the ones that will work with your 94 are 1988-1995
Hope this helps!

is the check engine light on ? if it idling high chances are you have a vacuum leak take a can of carb cleaner and spray the egr valve and if the engine rpm changes replace egr valve the throttle body may also be plugged pull the vacuum line off the map sensor start vehicle and see if you have vacuum if not remove throttl body and clean vacuum passage hope this helps