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View Full Version : Yeow!! She don't like long idling periods!!


Paul Workman
12-24-2007, 10:20 AM
Winter has pretty much ended regular forays in the Z for the winter season :cry:. But, I had to move it out of the garage several times over the past few weeks to use the space as a temporary woodworking shop. When I did so, I would let it idle for several minutes until it came up to operating temperature, and to top off the battery while it was at it. Apparently those periods of idling amount to a BIG MISTAKE:rolleyes:.

I suppose I ran it that way 5-6 times over the last 3-4 weeks. The last time I noticed it was idling rough (once again), and "woofing" the accellerator resulted in a LOT of stumbling and such. So yesterday the temps stayed below freezing (read: no slush or mud) and I took my baby out to "blow the cobwebs out a bit.

Wow! On the first moderate spurt of accelleration it missed and sputtered and ran like a POS! This was a total contrast to how it ran the last time it was out for a sprint. Well, after several WOT/7000 sprints over then next hour of driving (to and from a party) it returned to running like a "Z" should :).

I read somewhere that these LT5s get loaded up pretty easily, and NEED to be whipped like a rented mule to keep 'em in top shape - mine certainly seems to subscribe to that theory. But, based on my 5 years experience with similar winter storage idling procedures w/ my LT1 Vette, I was surprised by the amount of degradation the idling periods had on the LT5...From your experiences, are you surprised by this, or is that not characteristic of the LT5? I'm told the injectors were replaced before I bought it. (Hmmmm...sez me.:icon_scra) On the other hand, after some WOT/7000 runs, it came back to life (and boy did it ever!), so the injectors may be fine after all.

Well, all is well that ends well, but what say U 'bout this experience?

TIA,

P.

RedSled
12-24-2007, 11:10 AM
Interesting. I've only had my car a couple of years now and so far, I have had no "winter" issues. It might help that I seem to be able to get it out here and there for a sprint over the winter, but she always starts right up and runs like a champ. I guess I have noticed some high idles now and again, but overall, once she's warmed up, no issues.

- Keith '90 Red/Red #1383

bradslt5
12-24-2007, 11:18 AM
does your car still have the original injectors. my car had this problem with the original injectors . I got a set of rc injectors ,problem solved . hope this helps

Paul Workman
12-24-2007, 12:07 PM
does your car still have the original injectors. my car had this problem with the original injectors . I got a set of rc injectors ,problem solved . hope this helps

Injectors?? Yeeaaaaahhhhh...... I'm kinda wondering the same thing.:???: Well, I appreciate the feedback. I guess I'm warming up to pulling the plenum and maybe do a little inspection, some R&R, and cleaning...AND inspect and mebby change the injectors at that time too. What the heck...It IS a hobby, after all!:mrgreen: Sounds like a good winter project, huh?

P.

bradslt5
12-24-2007, 01:23 PM
plus a bonus is you have some very cool guys out your way to guide you if needed . pete and dominic are to awsome guys very knowledgable. i think all ya got to to do is ask and they will guide you through it . big thing is getting all the electrical connections disconnected under the plenum. there are 4 of them .

Z Factor
12-24-2007, 02:21 PM
It could be several things, but I am sure you checked a simple thing like the MAP sensor hose? Let's hope it is not the injectors.

:cheers:

Jeffvette
12-24-2007, 04:57 PM
You can check for faulty injectors by checking the resistence for one thing. But you can also get a fuel pressure gauge and check the leak down on the rail.

The car should start right up and run fine after sitting if everything is in good working order. But yes, they will have some symptoms after sitting for a while. Speaking of which if it dries out enough today I'll take the ZR-1 for a spin and fire up the race car as well and terrorize the neighbors.

Vette Guy
12-24-2007, 05:23 PM
I'd also recommend checking the coil packs.... throw a timing light on each wire just to be sure.... just happened to me a few months back.

Mark

Paul Workman
12-24-2007, 05:27 PM
I've looked all the hoses over and do not see any issues. However, something other than a cursory review may be in order. I wish I could spend hours/days on it to get it to 100%, but such self indulgences will prolly have to wait now till after the Holidays. Anywayz...food for thought!

Paul Workman
12-24-2007, 05:33 PM
Yes. I should have mentioned, I measured the pressure at the fuel rail. At idle it read a steady 43#. I shut off the ignition and after 20 minutes the pressure dropped only 2#. I haven't done a resistance check yet, Jeff. But, mebby tomorrw I can get away for a bit.

Jeff, thank you for your input. And, to you and all the members on this board, have a happy Christmas/holiday season - you and yours.

P.

Sgreg
12-24-2007, 08:29 PM
Interesting comments; I am convinced Z's discharge at idle. If the amps fall, everything goes to heck ( Christmas, you know ! ). These cars just have to have a battery tender in down time.

Paul Workman
12-25-2007, 01:13 PM
Interesting comments; I am convinced Z's discharge at idle. If the amps fall, everything goes to heck ( Christmas, you know ! ). These cars just have to have a battery tender in down time.

Now that you mention it, the battery charge seemed a bit low when I tried to start it in the cold, resulting in a little more sluggishness of the starter. And, at one point I was wondering if the engine was going to catch at all, or was I going to have to put the battery on the charger for a minute. I just chalked it up to the cold, but now I'm not so sure.:rolleyes:

Well, it might have been a while before I got around to questioning that. Thanks for the tip. I can check that easily enough: A volt meter across the battery teminals will tell the tail...Anything above 13.2 to 13.3 VDC would indicate to me the system is charging, and 14.5 or so would indicate the regulator was...well...regulating!:wink:

Did I mention that SANTA did bring me a new FSM this morning?? Now, hopefully I'll be able to back off on the dumb questions for a while. The manuals should help me climb the LT5 learing curve quite a bit, I should think.:mrgreen:

Thanks for your input!

P.

cuisinartvette
12-25-2007, 01:47 PM
paul,. Id replace the injectors in it, they can act funny and different every time you drive it. Sometimes good, then it stumbles, then a alight miss then is smooths out giving you hope all is well. Time for a plenum pull.

Jeffvette
12-25-2007, 04:01 PM
Did I mention that SANTA did bring me a new FSM this morning?? Now, hopefully I'll be able to back off on the dumb questions for a while. The manuals should help me climb the LT5 learing curve quite a bit, I should think.:mrgreen:

Santa brings the best gifts. I'm still waiting for my blonde 18 year old girl to show up though...

bradslt5
12-25-2007, 05:51 PM
that would be a great xmas present . the package would be awsome but then one has to deal with the ................. :blahblah:

Paul Workman
12-25-2007, 11:24 PM
that would be a great xmas present . the package would be awsome but then one has to deal with the ................. :blahblah:

Those 18 year old units can be HIGH MAINTENANCE - and I'll bet they hate long idle periods between WOT sessions too! (I don't believe I hijacked my own thread!!:mrgreen:)

Well, whatever keeps Jeff's watch wound up is OK with me.:wink:

P.

bradslt5
12-26-2007, 08:07 AM
Those 18 year old units can be HIGH MAINTENANCE - and I'll bet they hate long idle periods between WOT sessions too! (I don't believe I hijacked my own thread!!:mrgreen:)

Well, whatever keeps Jeff's watch wound up is OK with me.:wink:

P.A agree . but i just couldn't help myself after watching a buddy getting invovolved with a young one recently . he loved the bunny rabbit syndrome for 2 months, but the poor guy just couldnt figure out where here head was at.he just kept making the same sounds learch did when he opened the door on the adams family.:mrgreen: