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View Full Version : My "Z" coming out of hibernation mode...


Paul Workman
11-18-2007, 10:41 AM
My "new" 90 Z has been in storage for "several years", and honestly at first it ran (especially at idle) a little rough. I sorta expected that. Earlier I posted some scan results, and a couple of you pointed out some possible issues - one especially that caught my eye too was a possible lazy O2, as the cross counts on that side were quite low.

Well, I've run a couple tanks of fresh BP 93 octane thru it now, with some accelleration being "spirited", and the ol gal seems to like the exercise! I ran a couple of scans yesterday to see how things compared now after 3 weeks (weekends, primarily), and was pleasantly surprised to see all my left/right data is comparatively uniform now; and the cross count graphs of both O2 are nearly identical and very healthy.

I'm still experiencing an occational stumble when after cruising at low speed for several minutes. It happens - sometimes misses a heartbeat suddenly - immediately upon pushing the accellerator. I haven't had the scanner plugged in when it happend yet, but I'll bring it along from now on and leave it in monitor/record mode and see what's going on.

But, as some of you told me when I first got my Z, the more I drive it, the better it likes it. That seem to be the case! It has really come around a lot in a short time. It is like it is/was waking up after a long winter nap!

My wife, Ami, had an opportunity to take the Z for a drive. She reported that she came up on a pickup truck doing about 50 mph on a country blacktop and she decided to pass it. She said she down-shifed and floored it, and was rewarded with that LT5 thrill (we all love so well!). Her comment after was, "What a BEAST!" I just said..."Yep!"

She initially questioned my trading Vettes at first (makes two of us!), so I asked her if she thought trading my pristine '95 for the '90 Z was a good idea afterall? She said, "Absolutely!" I think we have another Z convert!:mrgreen:

Terrific board, BTW!

P.

Aurora40
11-18-2007, 12:20 PM
Are the injectors originals?

Paul Workman
11-18-2007, 12:36 PM
Are the injectors originals?

As I understand it, the secondary injectors (only) were replaced. I suspect it may be a sticking injector too, because it (and some other anomalies I alluded to) have fallen off with more driving. So, I'm hoping it is something that will "cure itself". However, injectors are "on the radar".:wink:

P.

LGAFF
11-18-2007, 12:44 PM
Paul,

Sorry about the multiple PMs, computer went nuts and kept sending copies......

LGAFF

FU
11-18-2007, 01:33 PM
Try some Redline fuel injector cleaner in the gas tank . It may help free up that sticker.

LGAFF
11-18-2007, 01:36 PM
This shows injector testing procedure w/o pulling plenum, most advise best done w/engine up to temp

http://www.zr1netregistry.com/forum/showthread.php?t=3017&highlight=injector+testing

LGAFF
92 ZR1
#234

tomtom72
11-19-2007, 06:49 AM
Paul,

Not trying to be a smart a$$, but the early injectors(OEM ones) are susceptable to ethanol induced failure of their coils, I think 90 thru 92 yrs. Just a fwiw.:o

On the excercise subject.......yea man, do it!

The Z will love for you to flogg it regularly. I learned that slowly and now that I accept it my Z is sooooo much happier.

:cheers:
Tom

QB93Z
11-19-2007, 09:29 AM
Paul,

On the excercise subject.......yea man, do it!

The Z will love for you to flogg it regularly. I learned that slowly and now that I accept it my Z is sooooo much happier.

:cheers:
Tom

I agree! I saw a tremendous improvement in my Z's performance after I started driving it hard. Full throttle to 7000 rpm, shift and repeat. At least once a day. Helps the car and helps my disposition too!:)

tomtom72
11-20-2007, 06:51 AM
I agree! I saw a tremendous improvement in my Z's performance after I started driving it hard. Full throttle to 7000 rpm, shift and repeat. At least once a day. Helps the car and helps my disposition too!:)

Amen Brother QB, Amen!!!:thumbsup:
....oh, yea, someone please pass the 93 octane fuel!:mrgreen:

Paul Workman
12-06-2007, 06:23 AM
Amen Brother QB, Amen!!!:thumbsup:
....oh, yea, someone please pass the 93 octane fuel!:mrgreen:

I think I have one injector that is still coming around slowly. Idle quality occationally is rough on one cylinder, but not so often now. Every time I take her out, I run 'er thru 7000 at least thru a couple gears, and some spirited accelleration (gotta clean the injectors, doancha know;)). I can report that y'all are right about it liking to be flogged a bit! It runs better n better alla time now. That idle problem has gone from "often" to "occational", and I'm hoping it dissappears completely soon.

The dang snow is flying around here already, so opportunities to blow the carbon out are gonna be slim and none for a while. :rolleyes:

P.