Chevy86 IROC-Z

iTrader: (17)

Fellow TPI owners, I need some help. Can anyone help me with the routing of a few hoses and vacuum lines? Please. You see, my uncle has worked on engines his whole life and I asked him if he was familiar with the TPI engine. Of course he said yes because of the money I offered for his help. Well after the overhaul, he seems to be completely confused of the routing of the hoses and lines. There are 8 areas of interest.

1. PCV Valve
2. Little pipe (male) on intake manifold
3. upper male outlet on throttle body
4. lower male outlet on throttle body
5. male outlet tube on driverside rear of intake plenum
6. vacuum line from fuel pressure regulator
7. vavuum line from EGR Valve
8. Little tiny male tube that sticks out under throttle body

Thanks, any help would go a long ways.
Andrew B. 86 IROC-Z

Chevy86 IROC-Z

iTrader: (17)

and the last picture is here.

89RESTO

iTrader: (5)

If memory serves me well, I believe #1 connects to # 2 via rubber fuel line.
#3 connects to pass. side pcv valve.
#4 connects to the vapor cannister.
#5 connects to brake booster.
I will have to look for the others when I have more time.
Hope this helps.

Chevy86 IROC-Z

iTrader: (17)

89RESTO Thanks for the help bro. Im looking forward to hearing from you agian. Ill be waiting. can anyone else help me out?

Nater2491

iTrader: (1)

6. vacuum line from fuel pressure regulator
i blocked this line
8. Little tiny male tube that sticks out under throttle body
goes to the evap canister, but im pretty sure its a t connection under it so it also goes somewhere else,

from looking at your pictures i wouldnt doubt if it went to 7 also

Chevy86 IROC-Z

iTrader: (17)

Nater2491, . One Question, Why did you block off this fuel pressure regulator line? Just thought Id ask.

IROCThe5.7L

89RESTO is right on.

#6 goes from the FPR to the intake on the passenger side:




#7 EGR goes into this guy:



#8 You should have a little skinny vacuum line coming from your evap canister, that goes under you're intake, which then splits. One half goes into that little TB male end, and the other goes into one of the male end in the picture above.



I hope I did ok, it's late and I'm getting sleepy.

Chevy86 IROC-Z

iTrader: (17)

.

89RESTO

iTrader: (5)

chevy86 IROC-Z ,did you get all your questions answered or do you still need some help?

Kodfish

iTrader: (1)

I know the routes are different on some years, but I just tore mine down, 90 SD setup, and EVAP hose routes to #4, PCV routes to #3, and EGR routes to #8. On the EGR solenoid these was a two hose elbow and the other hose off the elbow routed to the EGR valve.

Chevy86 IROC-Z

iTrader: (17)

To everybody that has helped me on this issue, I so much. Now I can go on with the rest of my overhaul. Thanks agian fellas.

Chevy86 IROC-Z

iTrader: (17)

Hey guys, look what I found. I found it here in our very own ThirdGen.org. My 86 IROC-Z is very slightly different but thanks to 89RESTO's very own pictures, it made my day so much easier. Thanks for the labeling 89RESTO . Well here are two different vacuum diagrams that Im posting so that anybody can refer to.

Chevy86 IROC-Z

iTrader: (17)

Hey fellaz, I got a new question for you, this hose here at the passenger side rear plenum goes into the HVAC right? So where is the HVAC vacuum line or nipple located at?

Chevy86 IROC-Z

iTrader: (17)

Anybody know where the HVAC hose goes?

vetteoz

iTrader: (13)

If the F-body is same as Vette then the HVAC line is part of the main wiring harness that runs across the firewall.small plastic tube sticks out maybe 2' from harness behind dist.

Vac line runs from port on plenum to one way check valve and splits. Rear port of valve to HVAC ; side port goes to vac ball and supplies vac to cruise control on the way (if fitted )

Chevy86 IROC-Z

iTrader: (17)

Here is a picture of what I believe is the Vac Ball. I couldnt find a tube running out of the wiring harness. none the less, the check valve with the splitter. Man this gets me pissed. I cant believe that my uncle is arrogant. That guy is such a drunk that he can smell the difference between a Bud Light and a Budwieser in the middle of a sewage plant. Thats why I needed help with the 2 loose wires, thanks to my uncle.. Well let me know if its the vac ball. Thanxz vetteoz.

89RESTO

iTrader: (5)

I'm not sure what year vehicle that picture is from, but the vac. ball on all camaro's i've ever owned is located under the drivers front corner kinda under the headlights. My est is a little further down behind the strut mount.

Chevy86 IROC-Z

iTrader: (17)

The pic. is from my 86 IROC-Z.

vetteoz

iTrader: (13)

Same on a Vette
Looks like this.
http://cgi.ebay.com/ebaymotors/1985-...%3A1|72%3A1171

The missing check valve you can buy generic from NAPA or similar and just run a rubber hose to the vac ball.

Chevy86 IROC-Z

iTrader: (17)

well I dont think Ill need the check valve because my camaro isnt equipt with cruise control. So I still could run a vacuum line to the ball right? Does the vac ball control the HVAC components aswell?

Chevy86 IROC-Z

iTrader: (17)

when I get a chance too, Ill go to my car and look for the vac line from the harness. Can it be possible that the HVAC line is somewhere else? For example a male fitting on the firewall perhaps?

Mr Froman

Wow, I've never had anything connected to #4 since I've had my car and it does not look anything was ever connected either...what happens if I leave it open like that?

hrspwr

iTrader: (3)

Ok here it goes, upper pass side of tb is air charge that goes to the valve train
lower pass side of tb is a vaccuum line that goes to the purge canister
then on the tb you have the coolant on the front and one on the pass side.
there is a little one on the lower side of the tb that goes to the egr solonoid. from the solonoid it goes to the egr.
pass side of the plenum, there are two. the front one is the fuel pressure regulator, the back one is blocked I believe.
driver side of the plenum on the back goes to the brake booster
the vaccuum beside where your cold start injector is, is your pcv valve.
Hope that helps, pretty sure that is all the plumbing on the intake.

Chevy86 IROC-Z

iTrader: (17)

hrspwr is correct on all his connections. but before my engine overhaul, it was connected. I had it labeled with tape but my drunk a** uncle took off all the vac hoses. Now im stuck on that last little male fitting at the rear plenum on the passenger side. I really need all the lines connected properly to pass CA smog. Here in CA, its very strict. If I dont get my IROC-Z running by October, my registration will go up agian. Currently the fee is at $330 after 6 years of being parked with no Non Op registration. So is there any pictures out there showing exactly where this HVAC vac hose go?

vetteoz

iTrader: (13)

The engine pulls a vacuum under most conditions, but not all. So the HVAC vacuum system has a small plastic reservoir in the passenger front fender to "store" vacuum. The check valve prevents the reservoir from losing vacuum when engine vacuum is low ( WOT). Without the check valve, when you accel, you will lose the vac to the HVAC controllers and they will change to the off position.If you have cruise , it will drop out also.
If you don't have the check valve you don't need the vac ball because there will be no vac to store; you will only have what vac the engine is pulling which is FA with the throttle open.

vetteoz

iTrader: (13)

The missing line to the vac ball and HVAC has no effect on emissions equip.
Handy to have so your A/c works properly but should not affect passing smog.

vetteoz

iTrader: (13)

You need to find a similar car and see where line enters firewall.The plastic line is thin and brittle with age so it may have broken off flush with the harness where you can't see it.

Found this online;yours could be similar.
91 z28 camaro , There are two hard vacuum lines coming out of a harness at the engine (passenger) side of the firewall

vetteoz

iTrader: (13)

You have a vac leak.

Chevy86 IROC-Z

iTrader: (17)

Good deal. On your second to the last post, was there suppose to be a pic? You know, I did consider seeing a identical IROC-Z 1986 that is. I met this guy at a speed shop. He is a correctional officer. The problem is that he lives about 25 miles away from me and he is the only other 1986 IROC-Z that I have seen in 6 years here in the Valley I live in. The only other IROC-Z around is my Bro N law, He gots a 1987 IROC-Z but he has since completely redone his "power plant." He dropped in a vortec engine with the Holley Stealth Ram so pretty much everything looks different than the way it was before the new block. Well Im going to have to visit the C.O. Thanks for the help Vettoz.

Chevy86 IROC-Z

iTrader: (17)

Vettoz is right. You may have a leak at the canister. Even worst, you may be introducing unfiltered air into your plenum. Remember, Connection #4 has vacuum so its pulling in the air in the engine bay, which is unfiltered. If connected properly, It pulls in the fumes I believe that is collected from the fuel tank. I would consider you reviewing this thread because I have posted 2 vacuum diagrams for our f bodies. Good luck Mr. Froman.

Chevy86 IROC-Z

iTrader: (17)

Hey guys, I looked around my firewall and found a little vacuum line coming out of the wiring harness. So I followed it and it lead to the canister that is above my brake booster. To verify if it is indeed my "Vac Ball", and sure enough, there is no vac ball under the front driverside or passenger side. So i connected the rear male port of the plenum directly to the canister deal and BOOOOM. My vac lines are all hooked up now. thanks for the help guys. If your curious about the little canister above the brake booster, check out the post above that has the time stamp of (07-26-2009, 10:55 AM). Click the pic to see what Im talking about.

DBLTKE

iTrader: (1)

Why is this thread not a sticky? There's some very good information in here.

Chevy86 IROC-Z

iTrader: (17)

How do I make it a sticky? I agree. Every once in a while, a topic on vacuum lines comes up.

lopezisgod

iTrader: (4)

Got a 91 z28 originally 5.0 now has a 88 tpi SD I have no vac lines connaected I found where everything goes except that I have this one issue. On the pass side in the rear of the plenum I have the 2 vac ports one is hooked up to the fuel pressure reg and the other to the map sensor... Car runs great but no hvac controls or cruise I have the vac lines al ready to be hooked up so I have it all working BUT I don't know where it ok to tee into for vacuum I know I can't use the map one but what about the fuel pressure reg can I tee in there??? Or do I have to get the vacuum off the port on the bottom of the throttle body??? Help would be awsome it's winter and heat is not there I could hook up the heater core so it hot all the time but I would rather hookit up the right way..

Thx for all the help I've been searching and got almost everything fixed except where to hook in for vacuum

Chevy86 IROC-Z

iTrader: (17)

for my 86 IROC, the 2 little male ends on the back of my plenum are used for FPR and the little male end under the TB, there is a T under the TB that splits off into the Vapor canistor. You can "T" off at the FPR because there will always be high vacuum at Closed Throttle than at Wide Open Throttle. Make sense?

Chevy86 IROC-Z

iTrader: (17)

Ohh one more thing. The "T" split connects directly into the wiring harness on the firewall (there is a small little vacuum line that sticks out). That should always be connected to the vac.line system. You mentioned "Help would be awsome it's winter and heat is not there I could hook up the heater core so it hot all the time but I would rather hookit up the right way.. " To eliminate the heat from having the heater core hook up, you will need a heater diverter valve which will stop the flow of hot radiator fluid from flowing into the heater core.

lopezisgod

iTrader: (4)

I know about the diverted valve I have it hooked up I have no vacuum to the valve since the hvac not hooked up that's y I need to get the vacuum from the right places and not mess up my sensors readings I have my egr disabled so I can just use the port from my throttle body then ..

Chevy86 IROC-Z

iTrader: (17)

Yes sir. you got it. One of the two that are on the back or the plenum are used for under the throttlebody and for the vapor canistor (in my 86). So since you got the map sensor hooked up to one of the plenum fittings, then you can diffenately T off on the TB-Vapor canistor because they are not sensors. So go for it bro. Let us know if you need more help.

dansm

Great post i had my vacuum hose's broken on my 88 iroc not knowing were they go i left them that way untill i came a cross this post they go to the egr sol.funny thing is now my heater works.before this all i got was cold air .thank you great job...

Chevy86 IROC-Z

iTrader: (17)

Anytime bro.

Mr Froman

Mine does not have this split. It goes straight from the TB to the solenoid...My canister hooks up to an outlet on the side of my TB...

megtom2

That is how the later models are setup. My 89 350 is that way.

DiabloWS6

iTrader: (8)

i have a similar problem on vacuum hoses but i figured it out for my 1986 305 TPI but wen i try to figure the 1989 350 TPI its hard and confusing for me i have put sum pics sorry dont got editing image to highlight what im trying to tell u so ill be as specific as possible hope fully anyone who knows this can help

remember this is on the 1989 350 TPI
Fisrdt pic is of the right side of the plenum the fiting or niple that doesnt have a hose where does that go to?

the second pic is the same as the first just at adifferent angle now the hose that is closest to the runner where does that hose go to cause its cut?

the third pic is the little black thing dont know what its called but the hose thats connected i think goes to the EGR and the other hole should travel to the bottom of the trotle body and spit to the canister but to the left of the little black thing there is a niple where does that go to?

if u guys have pics of 1989 350 TPI and can send me multiple angles, pics of the hoses i just mention for easier reference that would be appreciated send pics to Diablo1986WS6@hotmail.com

TTOP350

iTrader: (8)

That isnt a 89 Plenum. its a SD 90-92 and the black thing is your map sensor.In the 3rd pic your looking at you EGR sol

Chevy86 IROC-Z

iTrader: (17)

Black Bandit. Sorry. Id like to help you but Im mostly familiar to MAF, not MAP

DiabloWS6

iTrader: (8)

oh ok thanks for the help yeah i was wrong on the year i looked it up on the engine id and the head and its a 1990 sorry bout that but i fugred it out on the lines took me a while

DiabloWS6

iTrader: (8)

thanks for the reply chevy86iroc-z

Chevy86 IROC-Z

iTrader: (17)

yup.

dansm

on my iroc 350 the hose from the plenum there is a hose that comes and then there is a spliter that one side goes to the vacuum ball and the other goes to a small hose in to the firewall on passinger side.i found a 89transam at pick and pull with same set up and took all hose's and that spliter.good luck

pousaan

I could really use some help if anyone can offer. Of the two diagrams above, which one is for the 88 Iroc Z 350 TPI?