Wastegate Hose(s) & EGR

[87Limitedwo2]

I am in the beginning of sorting some things out on the 87 GN I bought. Has some very nice things done but I don't understand some of what was done. I have owned and built several of these cars mostly to factory spec with bolt-ons. This car has the waste-gage solenoid sitting on the intake manifold on the left side with no vacuum hose hooked to it only the factory wiring plug. The turbo and wastegate are plugged in together with the same vacuum hose.
Can someone clear this up for me: why eliminate the solenoid? and what does it accomplish by putting the hose on the wastegate and turbo? Any info here would be good.

Also, the EGR valve is there but no solenoid or vacuum hoses. I want it to look more original and plan to put the EGR stuff back on. Should I plug the vacuum lines so the EGR cannot work or is this not an issue?

Thanks in advance for any help,
Justin

 

[dank GN]

The solenoid is using the turbo pressure to open the wastegate . So all it's doing is bleeding off extra pressure to archive the set point . With the SD2 turbo tweak chip You can set the duty cycle of the solenoid .

 

[earlbrown]

All the wastegate solenoid does is raise the boost higher than the set point and aid in spoolup. What you have is commonly referred to as 'tuner style'. It's much more simplistic but offers slightly slower spool (depending on your combo).

The solenoid wired up without being plumbed is most likely one of two reasons. It might be 'turner style' from trying to diagnose a boost control problem. Bypassing that part along with the wye and two hoses can help climate problems and find issues.

The other potential reason could be because the previous owner just wanted it that way and unplugging the solenoid would throw a code. That depends on the chip.

As far as the missing EGR stuff, most chips disable the EGR so why not get rid of all that junk?

 

[87Limitedwo2]

All the wastegate solenoid does is raise the boost higher than the set point and aid in spoolup. What you have is commonly referred to as 'tuner style'. It's much more simplistic but offers slightly slower spool (depending on your combo).

The solenoid wired up without being plumbed is most likely one of two reasons. It might be 'turner style' from trying to diagnose a boost control problem. Bypassing that part along with the wye and two hoses can help climate problems and find issues.

The other potential reason could be because the previous owner just wanted it that way and unplugging the solenoid would throw a code. That depends on the chip.

As far as the missing EGR stuff, most chips disable the EGR so why not get rid of all that junk?

I have removed lots of unwanted wring: stereo, old alarm and improperly spliced stuff. I have the computer out of it now and will look at the Chip. There appears to be one wire coming from the PCM that is not in the main harness. It also has Alky on it now but I have not run the car only to put it on the trailer then in the shop. I have some plastic vacuum/boost hoses to repair and some other things to put back. No doubt I will need some good advice I will consider leaving the EGR off and putting on a block off plate. Will post what the chip is when I pull the cover.
Thanks for the reply,
Justin

 

[Chuck Leeper]

There appears to be one wire coming from the PCM that is not in the main harness. It also has Alky on it now

Is the alky system from ALKYCONTROL?? If so, that wire may be a part of that system.

 

[87Limitedwo2]

Is the alky system from ALKYCONTROL?? If so, that wire may be a part of that system.

It appears to be an Alkycontrol system. I have no experience with Alky---. I printed a PCM schematic and will ID what location and plug. I really want to keep the Alky and will need instructions so I can hook it up with proper connections. I was said to work so it may be just a wiring clean-up. Had 2 bulbs in the back of the cluster one I think is a "low fuel" for the alky. The other I am not sure.
Justin

 

[earlbrown]

If that odd wire is gray it might be to adjust the chip.

Does it run to the parking lights?

 

[87Limitedwo2]

It is gray. Funny thing is, the other end is not connected to anything (any more). 2nd funny thing is the console shift indicator is missing the feed wire. Could this be it? I have to ask: why would that wire (or would there be a wire) run to the parking lights?
It is in the large connector for the PCM and looks like D4 position which according to my schematic is supposed to be blank.
Guess Im going to learn something this time with these cars.
Justin

 

[earlbrown]

No idea then. If it was a wire to set a commander/extender chip it'd be at D11

The lamp wire for the shifter indicator is prone to get cut off by the shifter linkage. Ive been meaning to fix mine


....since 1998

 

[87Limitedwo2]

I will double check the location. I was in removal mode when looked. You wouldn't believe the butt connectors & scotch-locks.
It does have a TT Extender chip in it. Says TT Alc 60lb extender so it should be right for what I have.
Will check the PCM wire location & get back.

 

[87Limitedwo2]

The unknown gray wire is definitely at D13, not D11. According to my schematic, both locations should have been empty from the factory. The other end doesn't look like was connected to anything ever. Perhaps it was installed for future Extender use? Installed at the wrong location?
Im not sure where the wire is for the console shift light. I see the receptacle for what would have been the ashtray light. Could it have been jumped off of that from the factory? I guess that's what I will be doing to get it power----.
Justin

 

[earlbrown]

Not sure if the TT extender uses the same slot. I know Bob's extenders use D11

I'm sure Eric has the instructions on his site.

 

[87Limitedwo2]

I will put a note to Eric for instructions. What are your thoughts on Knock gauges. This car had one but I was going to remove it. Also has a ScanMaster.
Justin