ctgreg

Hey all,

I had my 1990 out yesterday for a drive and all of a sudden the SES came on. I drove home and ran through a few things. One thing I noticed is that the vacuum pump is running non-stop when ignition is in the "on" position, but it appears that it's not running when car is running. I pulled a Code 16, but for some reason I can't seem to correlate one issue w/ the other. I tried clearing code, but no go.

I also checked all vacuum connections and I can hear one connection in under left front of plenum where two line are attached.

Any and all advice would be greatly appreciated.

Thanks in advance,

Greg

LT5corsa

Hey Greg!

How far are you from Baltimore MD? Consider a drive where we could help with a fix?

Post up here too... www.zr1.net/forum We have a get together on the 27th (Tearndown of an LT5)

PM me your email.



David

C6FirstVette

Greg,
Come on down as David suggested...we have quite a great group of ZR-1 owners and many of them very knowledgeable on the details of the ZR...sounds like you secondary actuator system (pump/lines/actuators etc) have a leak which is not uncommon for the ZR.

There is a test you could do just to get diagnostic things moving... if you can get a vacuum tester which seen in the lower left of this pic>>


And pull the line from the connector in this pic and use the tester to see if it hold vacuum>>



That would confirm at least a failure of lines etc under the plenum.

But, if you do not have this tester etc. just let us WAZOO folks (Dave in particular) know and come on down..
Michael

Goldcylon

Nice of you folks to help

Paul Workman

Pull alla dat secondary sh... um "stuff" (being nice), put in one of Marc Haibeck's "removed secondaries" chips, and say farewell to prolly THEE most common problems with these ol gals. It makes for a much better ride, and some other features too (e.g., fan control, idle control, no backfire w/ headers, throttle response).

Sorry to sound like a broken record, but IMO there is no upside to keepin' the secondaries. If it is important, just hang onto the stuff in case you want to reinstall it for whatever reason. In the mean time, you will appreciate how it runs w/ "all 16" running full time (except at idle it = 8 injectors only).

Now, I removed the throttle plates, rods, the whole deal; no going back for me. But, some simply tie-wrap the secondary throttle plates open and go with a modified chip (such as Marc's), w/ the idea of being able to revert easily.

Just a thought (and I'll shut up about it!)

P.

ctgreg

Thanks, Michael.

I have a vacuum tester and will look into the issue. I do have manuals albeit they're for a 92...mostly similar.

I will most likely take the ride to Balt. to meet a bunch of good folks and am looking forward to it (as long as it doesn't rain!.

Greg

ctgreg

Thanks, Paul...not a bad option. I'll be looking more closely at the issue this week to narrow down the issue. I'm confused on why I'm getting code 16 as there appears to be no correlation w/ the vacuum issue.

Greg

tomtom72

Having been thru a DTC 16 I have to say that you are correct, there is no relation to the vacuum leak. Also, it is rare to have the DIS fail.

Please don't be offended by my question. Have you disconnected the main harness connector to the DIS box recently? I ask because it is easy to bend one of the pins on the box when reconnecting the harness connector. I did it to mine.:o If you have a bent pin and go thru the trouble shooting flow chart it will tell you the DIS is no good. It's the bent pin that is yielding the result though.

Barring any bent pins because no one has moved that connector, then use the DTC16 chart to do the diagnostics. All you need is a DVM and a standard test light. The flow chart is not hard to follow and execute and it will tell you what's up.


Tom