1990-1995 ZR-1 Secondary Port Vacuum Diagnosis

**Rob** · 10-28-04, 06:47 AM

Originally Posted by ROUTE66

Hi Rob. Thanks for your write up. I have a problem. My ZR1 has a vacuum leak! I called the local Chev dealer to get a new vacuum hose assemble. part #10145221, They told me they are no longer avallable from GM. Do you or anyone else know where I can find a new one? Thank You. Eli.

Eli,

What does that part number go to?

**ROUTE66** · 10-28-04, 03:27 PM

Originally Posted by Rob

Eli,

What does that part number go to?

Hi Rob. Thanks for responding. It's called a Secondary port vacuum hose assembly. I got that part # from your post on[Secondary port throttle vacuum leak diagnosis] In one of your pictures it shows a set of vacuum lines & down below the picture is that part#. Im the original owner of a low milage 93. The other day when I went to start it it backfired & blew off a vacuum line at the MAP sensor. I put it back on IT runs ok except sometimes it has a slite hickup when giveing it gas after up shifting. I also found a small amount of oil in the vacuum connection at the MAP sensor. So I thought I would replace the vacuum lines. Any help would be very much appreciated. Thanks.

**bpouls2009** · 12-21-09, 06:26 PM

Thank you for the great info Rob! Like the picture of the Visitors!

**abbezr1** · 07-19-10, 01:26 PM

Rob, great write up!! I'm a new member to the CAC and also a new member to the Corvette world. Being new I have been going through old post and really any info I can absorb to better understand the zr1. My z runs great and the previuos owner had the plenum off when he repaced the starter and checked for any vaccum leaks when he put everything back together. He said eveything underneath looked new, he said the dealer he bought the car from had just did a full tune up. I doubt they did. The wires and the plugs look original to me. My question is after reading this post I went out and turned the ing to the on position heard the pump come on and go off, but it came back on in about 15 seconds went off and then came back on in 15 seconds and just kept doing the same cycle. Is this normal or is this what you ment by cycling on and off? I will buy a vaccum tester this week and run a test that you outlined in this post. I want to thankyou again for so many of yours and everyone else on the forum that has the experiance with these awesome cars and shares that info with us newbeies.

**Willard** · 01-24-11, 08:37 PM

My vacume pump cycles on and off but has no affect on the performance of the car. As long as the pump maintains vacume why go to the trouble of replacing lines if the leak is not that bad?

**Willard** · 01-25-11, 10:59 AM

Are there any qualified mechanics in California that will work on the LT5 engine?

**Willard** · 02-10-11, 08:25 PM

The Secondary Port Throttle Control Solenoid is not working on my 1990 ZR1 and is no longer available. The dealer can only get one that looks similar part # 1997201. The connections are slightly different.
Anyone know if this part will work.
Thanks

**HAWAIIZR1** · 11-28-11, 04:42 AM

Originally Posted by Willard

The Secondary Port Throttle Control Solenoid is not working on my 1990 ZR1 and is no longer available. The dealer can only get one that looks similar part # 1997201. The connections are slightly different.
Anyone know if this part will work.
Thanks

Good question! BUMP!

**xfirez51** · 11-28-11, 06:49 AM

If this is the vacuum solenoid from a Suburban or Escalade. the answer is yes. This topic was
recently addressed at the ZR-1 registry. the bracket is different but can be modified to work.

**Hib Halverson** · 11-28-11, 10:12 AM

Use the truck part because all you need do is adapt the different bracket to the LT5. With the other choice, it sounds like you have to change the wiring and connections which may decrease reliability/durability.

Anyone have the PN for the truck solenoid?

**HAWAIIZR1** · 11-28-11, 12:45 PM

Thanks Dom and Hib,

Hammer (John) sent me this link and now I remember seeing it last year: Secondary port vacuum solenoid - ZR-1 Net Registry Forums Not sure if this is from a truck or not.

Craig

**xfirez51** · 11-28-11, 02:49 PM

Craig,

Here's the post from the Registry that explains it pretty well.

Holding the box in my hand, ACD# 214-358 with GM# 1997212

ZR-1 Net Registry Forums - View Single Post - Secondary port vacuum solenoid

**HAWAIIZR1** · 11-29-11, 03:17 AM

Originally Posted by xfirez51

Craig,

Here's the post from the Registry that explains it pretty well.

Holding the box in my hand, ACD# 214-358 with GM# 1997212

ZR-1 Net Registry Forums - View Single Post - Secondary port vacuum solenoid

Thanks Dom. Man, this one is only $18 in Amazon.com; great deal on a substitute item.