acammer

iTrader: (1)

Hey guys - good to be a part of a new forum. I'm a long time member over at thirdgen.org, but new car needs a new forum and this seemed like the most active LT1 spot.

So, I bought a 1996 Z-28 convertible yesterday to replace my 1986 Camaro thats way more race-car than daily driver, and just isn't working out for daily driving like I want it to. (BTW - its in NY, and forsale if anybody wants a great SCCA car, this thing is a slot-car) So, the new Z is great, I'm coming from a carb'd/cammed 305 motor backed by a stalled 700R4 and 3.73s, and now I'm in the T56 world and everything is so different. Always wanted a stick F-body, but always wound up w/ auto's. The car is near stock, just a K'n'N FIPK and cat-back, and what seems to be some sort of aftermarket shifter - its a Hurst T-handle, on a shorter than stock arm that curves toward the driver -anybody know what model shifter that might be?

Here are the questions. First - T56 noise, wow! The trans makes a good deal of noise some times when lugging off the line, or on the dreaded skip shift upshift. You can hear/feel it through the shifter, and hear it outside the car. From what I understand from my reading in the last few days, this is pretty normal, right? I have a tiny bit of clutch vibration at partial engadgement - and occasionally get the clutch to make some noise as well, but other than that it rolls plenty smooth. When should I get concerned, when it stops working right? It shifts great, no problems going into gears stopped or rolling, stays in reverse under load, etc.

Second - the clutch. I've read there is a fitting in the clutch hydrolics that slows down engadgment, would this be cause a slight slip on real quick upshifts at WOT. (Obviously lifting between gears) I've noticed if I'm really quick between 1-2, 2-3, or 3-4 I get a little bit of slip, but it does hook up all the way fairly quickly. I cannot get the clutch the slip under high loads in any of the higher gears, I can pull WOT in any gear at low revs without any slip at all. Does this seem pretty normal. The car has 72,600 miles on it, I'm not sure its ever had a clutch. What does one pay to have the clutch done? I've done my own wrenching, and will continue to do so, but I'm not into the jobs better suited to a shop with a lift and trans jack. Looks like my parts options are in the $350-500 range, correct?

Third - Idle speed - this car refuses to idle below 1000rpms. It acts just like it should, does a high idle (1200-1500rpm) in neutral if your coasting down to a stop, but when it drops the idle, it settles right around 1000rpm. It idles up on warmup like it should, it just always runs a 1000rpm idle - I've read mixed opinions on this - some have had cars do this from there first day off the show-room floor, others seem to have M6 cars that idle at about 600rpm, where I think a hot-idle for a v8 should be.

Finally - the car has an SES light. When I looked at the car, the light was on, stopped in on a shop and had them pull the code on the test-drive - evap sensor or something like that. I had them clear it, and it stayed out for about 100miles and 2-3 driving cycles. When I took the car to lunch just now, it was out when I started the vehicle, drove about 2 minutes to the freeway on-ramp, and got into the power some, but not super hard. Light pops back on. I haven't pulled the code, but I'm sure its the same one, no other codes were in the memory when I had it cleared last time. Any thoughts? Gas cap is brand new, just filled it up yesterday.

Few other random questions - is a vert heavier or lighter than a reg hard top car? Is the car subject to a lot more body flex? It feels as tight as my hard-top third gen.

Anyways - I appreciate any thoughts you guys can give me on all these newbie questions - this 4th gen stuff is a new ballgame for me after 10 years with third-gen's.

BigZee71

iTrader: (5)

The noise from the trans (so Ive been told) is detonation vibrations that travel through the trans and makes the noise. Its best to try not to lug the engine but the noise you hear is somewhat normal. All mine did it. As for the skip shift, do a search and find the right size resistor which can be bought at radio shack, and then simply slide the resistor into the pigtail that connects to the skip shift silinoid and voila... no more skip shift (CAGS). I think its a 2.2 ohm/ 4watt.

With those miles and the original clutch you might want to start planning for a new one. I do not beleive that the LT1 hydrolics have what your talking about. Cant remember what its called (drill mod) but I think its only on LS1 hydrolics. And yea verts are a little heavier.

For the SES light, might want to start by checking for vacume leaks, could be the high idle problem as well. May also want to pull the IAC valve and give it a cleaning with brake cleaner.

ss.slp.ls1

iTrader: (36)

Maybe this will help a little (sorry, didn't read your post).

https://ls1tech.com/forums/lt1-lt4-m...ewbie-faq.html

acammer

iTrader: (1)

I hit up the newbie guide, it handled some of the basic stuff - none of my questions would really be addressed by that.

Vacuum leak = high idle, makes perfect sense, and I'm sure the IAC wouldn't mine the attention. Yea, I figured I'd be in for a clutch within a year on this car, I guess I'll try and nurse it along gently for a bit. CAGS isn't a big pain, but I will probably eliminate it at some point - and I don't typically run the revs down in the under 1500rpm range anyways so the noise isn't a big deal, just a concern.

acammer

iTrader: (1)

Anybody else have any input...

97HawkLT1

iTrader: (11)

There is also a good chance that the tachometer is showing incorrectly. Somebody told me that once and I felt like mine was correct but when I checked it with scanning software, it read about 300 RPM high. So if it says 1000, it could be 700. Yours could be off by more or less or none but just thought I would let you know.

CAMJAG

iTrader: (34)

Here is another good page to check out for LT1 stuff

http://shbox.com/1/4th_gen_tech1.html

TurboBob

iTrader: (1)

I believe the stock idle speed (at least on my 94) is 800, my tach shows about 1000 at idle, Scanmaster shows 800-ish. My car also hangs a bit on decel, I think thats an emissions trick, or to keep the vacuum high for the brakes.

If you have a vacuum leak, the block learn numbers will be high at part throttle and idle. You should check that also. 128 +/-5 is good for those.

I'm not sure if the evap code on these cars is anything but a circuit-check of the solenoid. What code number was showing?

Bob

acammer

iTrader: (1)

Code is a P1441 - evap purge when its not supposed to - or something along those lines. I cleared the code last night when I left work at an auto-zone. Did about 30 miles home, and two more 15 minute drives, no SES. 2 minutes into my commute this morning, SES. I don't have have scan equipment for this car, so I can't check the fuel trims yet - I'll probably buy an Aeroforce scan gauge, I used to run one of those in a modified Grand-Am I had, and it was a great tool. I guess I'll take the valve off and see if its stuck open - seems like it might just be sticking open occasionaly, maybe a lube and reinstall will take care of that.

The idle speed is probably about right - if the tach is showing 950-1000 its not a stretch to imagine it really being 800rpm and that being tach error. I don't know where the stock rev-limit comes on, but I've had the car to about 5800rpm in the gears and didn't bump anything - maybe the tach is reading under on the top-end as well.

Just started raining outside - I guess I'll find out how the top is for leaks on the ride home - seller says its good but you never know till you find out yourself.

TurboBob

iTrader: (1)

oops, I was thinking you said you had a 95, 1996 is OBD-2 and the BLM's are now called trims and are +/- percents. But since you have used an interceptor before, you know the deal.

I have a 96 manual at home, I will look to see what it says for P1441

Bob

acammer

iTrader: (1)

From the link above - P1441 Evaporative Emissions (EVAP) system flow during non-purge

From what I've read, its possible/likely the charcol canister is coming apart some, and could be jaming the purge solinoid open - I'll blow out the line and see if I get charcol.

Yea, I'm already kicking myself for not keeping the Aeroforce gauge - I had one of the very first ones ever made - Todd, the guy that does them, is a real stand up guy, I provided him feedback on a few things for working out bugs on the gauge, he upgraded me down the road at no charge to the newer style gauge, I recommend those things to any OBDII modder I see. We'll see on this car, its a nice diagnostic tool but I probably won't go for big power in a convertible, so I may leave the car fairly stock-ish and just enjoy it as a cruiser.

Funny you had a few TT Stealths, my fellow car guy at work had a 94 3000GT TT, just stock turbo's w/ all the bolt ons, but still very quick, probably low 12's and a strong enough launch to put your stomach in the trunk.

jaywalkersw

Your idle sounds a little high. My cold idle is about 1000, and my hot is 650. All this is on my stock tach,so there is some margin there. Also welcome to the forum.