I am at the end of my rope, vacuum problems.

[mrbuyit]

Hello board. My 87 GN with 33k miles was runing bad. Stalling under boost, dying, etc. I originally thought that I had a bad coil pack or module. Had both checked, work perfectly. Thought I had a bad senor, had the system checked, everything was perfect. Notices that the large turbo hoses were lose, tried to tighten factory clamps, some were worn out. Replaced hoses with new cool red ones and heavy duty clamps from GBody. Well now car runs better, but after a while, when boositng, usually between 2nd and 3rd gear, I hear a pop, and it blows off several vacuum lines. I have attached pictures of the hoises that blow off. One is coming out of the wastegate solenoid to a tee, blows off at the tee. Another blows off at a circular thing on the other side of the engine. Third blows off behind the wastegate soleniod, closer to the firewall. Its a harder plastic line that leads to some sort of switch on the inner fender. i included a pick of that as well. What would cause this? Does anyone have any idea what could be wrong?

I appreciate the help.

Jeff

 

[krom415]

I was having same problems w/ some vac lines, i zipped tied everything ..no more problems

 

[87granny]

Wire tie them in place it should keep them from popping off also how high is the boost?

 

[mrbuyit]

I was having same problems w/ some vac lines, i zipped tied everything ..no more problems

I did that tonight, didnt have a chance to drive before it rained though. I was thinking that the vac line thing was a symptom of something more serious as it just started to do it.

 

[Deebar]

IMHO, zip tie ALL vacuum connections. Life will be much more enjoyable.

 

[mrbuyit]

Wire tie them in place it should keep them from popping off also how high is the boost?

not quite sure on the boost, car is basically original with the exception of a 92 octane chip, 160 thermostat, and a tinman kit. stock boost gage pegs at 15 when I hit it.

 

[BoostedEvIL]

I was having same problems w/ some vac lines, i zipped tied everything ..no more problems

+1.
I think that switch your referring to is the map sensor. Is the whole line blowing off or just the plastic line?

 

[mrbuyit]

+1.
I think that switch your referring to is the map sensor. Is the whole line blowing off or just the plastic line?

On the passenger side, the side with the hard plastic line, it blows of at the connection in the picture only, not on the passenger side firewall which it leads to.

On the driver side, that round disc, it blows off at the disc where I have it circled.

 

[krom415]

not quite sure on the boost, car is basically original with the exception of a 92 octane chip, 160 thermostat, and a tinman kit. stock boost gage pegs at 15 when I hit it.

I would not rely to much on the factory boost gauge very inaccurate .

 

[krom415]

And for the one that attaches to the map sensor you can replace it with a regular vac. line and zip tie it at both ends

 

[viper04]

Ture

IMHO, zip tie ALL vacuum connections. Life will be much more enjoyable.

That so ture.

 

[gnbooster87]

zip tie ALL vacuum hoses and make sure you get a good zip tie on the sensor on the passenger sensor(map sensor) as if the line pops off while under boost the car can go lean and its possible to blow a headgasket

 

[TR Custom Parts]

Sounds like a real boost gauge is in order quick or you may have more problems than just blowing off vacuum lines.

 

[Chuck Leeper]

"but after a while, when boositng, usually between 2nd and 3rd gear, I hear a pop, and it blows off several vacuum lines."
If the lines blowing off comes after/same time as the "pop", it sounds like the engine went lean, and backfired, and blew them off.
The lines you have circled:
Dr side is the EGR valve.
Top of pass valve cover, the boost solenoid.
The pass fender is the MAP sensor that operates the dash boost gauge.
As Mark has said.. Get the correct gauges B4 you blow it up.
IMO, these are the MINIMUM:
Scanmaster.
Boost ga.
Fuel psi gauge.
Oil psi.
Water temp.
Sounds like a complete "spring cleaning" is in order, along w/ several hours of reading.
A fuel system upgrade is a definate necessity.

 

[Just a Six??]

Before you Zip Tie them use some Hairspry on the ends & it acts like glue. Altho still easy enuf to remove when needed.
As mentioned you need a Scanmaster & boost guage at Minimum! I would Never drive a car without them.

 

[ijames]

To add to the good advice already given, in the first picture the large black disc is the EGR valve. To the left and below the EGR valve where the vacuum line connects to the metal line is a black and white plastic disc in the vacuum line. This is a check valve to keep boost out of the egr plumbing and also out of the ac/heater controls in the dash. If you are blowing off the egr hose this check valve is probably toast - pull if off and try to blow through it each way, should only get flow from the white side to the black side. There is another vacuum line close by that runs across behind the alternator and towards the fender behind the drivers headlight, that has another check valve in it that also needs to be tested. The last pic shows the boost solenoid on the front of the passenger valve cover. This is only supposed to have one hose going to it. Some cars got a little foam filter on the other fitting, some just left the fitting not connected to anything. Do not cap off this fitting or the boost will drop a lot.

 

[TurboDave]

not quite sure on the boost, car is basically original with the exception of a 92 octane chip, 160 thermostat, and a tinman kit. stock boost gage pegs at 15 when I hit it.

Part of your problem could be that you're seriously OVER boosting and don't know it. The stock boost gauge is notoriously inacurate.

Your first priority before getting into boost anymore!!!!!! Is to get a good boost gauge!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!