Your little helper: A simple diagram that may help you to solve malfunctions in your TBI vacuum system.
applies to |
|
|---|---|
Brand |
Chevrolet |
Model |
L03 (5.0L) and L05 (5.7L) TBI engines |
Year |
1987-1993 |
Maybe you know the problem: I've hundreds of pages of wiring diagrams, but only one incomplete vacuum diagram in bad printing quality. If you search the internet or look at your repair manual, you'll find stuff like this:
The image only shows the vacuum lines that belong to the emission control system. Next problem, if you have no idea how an EGR Solenoid or MAP Sensor look like, you might have trouble finding the parts at your car.
This might help better:
The vent port of the EGR Solenoid is the short and smooth terminal. Do not attach any vacuum or pressure line to that port. Keep it open.
The EVAP Canister (Vapor Canister) in this diagram has the purge valve attached (left side, two lines attached) to the canister. Many cars have the purge valve seperated.
15 comments
Comment from: Dan Visitor
Comment from: Garth Visitor
The Red colored Vac lines are a rigid plastic type that will not collapse when under a high vacuum. They also become very brittle over time and heat cycles and crack.
Anyone know where to find these types of plastic lines to replace them?
Comment from: Aaron Visitor
I have a 1995 350 the driver side valve cover a hose going to a hole dont know name of part that goes in the hole. there is oil sparing all over under hood. Can you please help me?
Comment from: christopher mathus/russell Visitor
thank you this was what i was needing to see you earned a 10 out of 10 with me
Comment from: Luke Visitor
You’re an absolute legend, thank you!
Comment from: John Visitor
What does it mean with that green line to tank? Thanks
Comment from: zapp Member
@Aaron:
You have a TBI? The hose should go from the valve cover to the TBI (to the spacer between TBI body and aircleaner). If it’s messed up with oil at this location, you should check if your PCV is clogged.
@John:
The green line is the vent line that goes to the tank. You have three lines attached to the tank: fuel line, fuel return line and ventilation. The vent line is missing on cars with ventilated gas tank caps.
Comment from: bubs Member
Due to a cam change I am short on Vacuum at idle.Is there a way to add a vac pump in the system to solve this problem. I turned the idle up and it runs great. But I have rpm on cold start faster than I like.Any advice would be much appreciated! Thanks for looking.
Comment from: George Elliott Visitor
Why hasn’t my question posted?
Comment from: Frankee Visitor
Thank you so much! This is my 5.7 tbi diagram! 1st correct diagram for my vandura!
Comment from: zapp Member
@ George Elliott
I’m sorry, I’m a bit lazy reviewing the comments and sort out the “buy viagra", “buy addidas", “Trump is the best president ever” comments…
I promise, I’ll check the comments more often.
Comment from: Alan Grafnitz Visitor
87 tbi I’m building up pressure in my gas tanks and gas is coming up to the fuel evaporative canister and flowing out the air vent on the canister, was reading a thing that told me I could plug the purge line and the tank line to bypass the canister, but that makes the gas flow out the gas fill caps,,,,when you open the caps ,,, can you help me please
Comment from: Steve Visitor
This is the only site to give enough clear information and pictures to know I was installing this sytem back correctly. Thank you for the details.
Comment from: NotUsedToAmericanTrucks Visitor
This is the only chart I’ve found in 4 days that helps. I didn’t even know the name of what I broke before. Thank you.
Comment from: m198gnnr Member
@Garth, I gave up trying to find the plastic ones in good condition. I ended up with copper ones that a refrigeration buddy of mine made. He swaged it to a different size on one end to make it fit right.
If nobody has ever told you…..
Great job!!!
Awesome idea Very helpful.