Re: TOP END REFINISHING
 

No 2-part epoxy - you don't want to have to use a grinder or "crow-bar" for removal. Black RTV I would think will do well. Window-weld - maybe?

Re: TOP END REFINISHING
 

Ok or that

Re: TOP END REFINISHING
 

I can do that :dancing. When you can email me and we'll get-r-Dunn :handshak:

Re: TOP END REFINISHING
 

Anyone know off-hand the size of the crank pulley bolt head? And is it reverse-thread?

Re: TOP END REFINISHING
 

Black RVT is all you need to lock the emblem down...my emblems are 2X the weight and never had an issue with RVT

Re: TOP END REFINISHING
 

21 mm, right hand thread

Re: TOP END REFINISHING
 

You need to turn it over with the starter, 2~3 compression strokes. By the time you reset the wrench enough times to make a full 4 stroke cycle, the pressure is leaking off past the rings.

Re:
Not sure what you mean by "open" and by "pucker"

If you mean the intake valves were open on #4 cylinder and you were applying vacuum to the cylinder via the spark plug hole..... and...the tape sucked down (like a vacuum would)..... a lot on the primary & only a little on the secondary, It's probably because both intake valves are open and the secondary port throttle valve is closed.

Re: TOP END REFINISHING
 

Thanks there Sir; that explains BOTH Q;s...

Re: TOP END REFINISHING
 

Schrade, You might also want to make sure you have a good charge on the battery to do the compression test on all cylinders. Take the tape off the intake ports so that you don't suck any tape into the cylinders.
Like Jerry says 2-3 compression strokes per cylinder should give a good indication of cylinder balance. I go 3- 4 strokes to make sure I've reached max pressure. Watch each stroke to see what pressure you get and compare each cylinder. For example: 1st stroke 50lbs, second stroke 100lbs, 3rd stroke 130lbs etc. Some manuals say that there should be no more than 10% diff between highest and lowest final cylinder readings.

Re: TOP END REFINISHING
 

You could fashion a metal strap to go around the pipe to attach to the plenum bolt. My car is missing those attachment points from the aluminum pipes as well. Seems that they were somewhat flimsy and required care in removal.

Re: TOP END REFINISHING
 

Nice right up Schrade. Much braver soul than I tearing into it like this.

Re: TOP END REFINISHING
 

There is a fine line between bravery and stupidity. So far, so good on your part.

Re: TOP END REFINISHING
 

Maybe fishing with a magnet could help?

Re: TOP END REFINISHING
 

Had to laugh!;) But I lost a 1/4" drive ratchet handle...exactly doing what you were doing. It NEVER hit the floor, and I spent a couple hours looking for the damn thing and never found it! SO! If you find your socket, see if my ratchet handle is there too! :sign10:

Re: TOP END REFINISHING
 

FP test; I blew something at #8, or at rail cross-over, P side. I heard the air right away, and let off the jumper, then saw some drops - not enough to see exactly where, but enough to see tomorrow's starting point... :neutral:

Inside work now; carve up C4 / ZR1 decal for TB extension...

And bury under some poly...

https://lh6.googleusercontent.com/--...0/HPIM7495.JPG

Re: TOP END REFINISHING
 

You should do a separate post on how to make those DIY clear decals.

Re: TOP END REFINISHING
 

Add to the list of How-NOT-To's

After re-assembly of the P side rail LAST night, I did the FP test, and failed. I heard the air blowing, and let off the FP jumper.

Today, I found out why

https://lh3.googleusercontent.com/-M...0/HPIM7496.JPG

When I sank the rail, I sheared off part of the O ring, just as clean and neat... That piece is probably under the starter. Guess where it's gonna' stay :p

When I broke it down, to find the wayward socket, the gasoline that drained from the INJ port, out of the rail, rinsed off the oil, and the port dried out. It HAS to be clean, AND OILED, as Jerry was saying. It was clean alright... :-x

I had O's from LT1 top end re-work, and replaced it. WITH oil.

FP test result - tested with primary FP only, was identical to earlier FP test. The secondary FP, when plugged in, forced the air out (((not done yet; it was low 30's wind chill. If I'd had a wooden stick in my ace, I coulda' been a popsicle http://www.smiley-lol.com/smiley/sai...iver/glace.gif )))

Re: TOP END REFINISHING
 

Schrade, make sure that new O ring is Viton for ethanol fuel. In the pic it looks like a different color from the others and I was wondering if is was Viton or BUNA.

Re: TOP END REFINISHING
 

Still working dry-fit to anticipate problems...

Between which 2 injectors does this vacuum hose go, that comes into the plenum P side center...

I have it where I found it, but it ain't 'sittin' exactly happy where it is...

Help? Again???

https://lh6.googleusercontent.com/-z...0/HPIM7501.JPG

Re: TOP END REFINISHING
 

Schrade, looks about right ... not sure why its being difficult. Perhaps its stuck under the plenum. Check post # 37 to see if any help.

Re: TOP END REFINISHING
 

Where's Cliff here - is there a sequence / write-up for vac test with plenum dry - fit, with all electrical connections? Is it in FSM?

The one in the snappic ON THE INJ is the original one - sheared off. Looks different because it's dry - reason it sheared off too.

Don't know the make of the LT1 kit from which it came...

I had it mis-routed - post 37 DOES actually show it between 1' and 2' INJ's...

Checking for Vacuum Leaks
 

Post #267 a bit before you were ready :D

Before you tighten down the Plenum (with Plenum tipped up in front) and ALL vacuum lines, and DIS module connections in place....check your vacuum systems.

With all vacuum lines connected, turn key on and listen for vacuum pump to shut off. If it does not shut off, start at the closest vacuum line to the vacuum pump disconnecting the line and holding your finger over the end. If the pump shuts off the leak is on other side of that. Go to next fitting and do the same until you are past the leak wherein the vacuum pump will NOT shut off. You have now located the leak.

Also check your HVAC and Cruize Control Vacuum System (check ALL connections). Also check your EVAP Purge system connections (charcoal canister which is under drivers side headlight on your 90'). That single small vacuum port under front of plenum facing rearward (90' only) is for the Evap Purge System. The second larger vacuum port on drivers side lower front of plenum is the main vacuum line for the Charcoal Canister. The second Vacuum port right next to that Charcoal Canister port is your PCV Vacuum port.

With the key on, ground the pink wire in the green connector (third from drivers side) on ECM. Use a small finishing nail stuck in alongside the wire connector with an alligator clip pigtail attached to the end for grounding. This will activate the Secondaries which you can watch with the plenum tipped up in front before you bolt it down. This after you are sure you have NO vacuum leaks in the Secondary System.

I promised GC I would not mention any modifications .....but you should eliminate TB coolant so you do not have to mess with coolant every time you remove the Plenum......DO NOT TELL GC I suggested this :D

Vacuum Systems 90' and 91' (Secondary and Cruize/HVAC)

Re: TOP END REFINISHING
 

Nano-surgery.

There was a tiny bit of the screw sticking out of the front side, but not enough to get Vise-Grips on it.

So hello Dremel. I got a grinding bit centered in the backside, so I should be able to get enough bored out without touching the threads. Getting the screw remnants out will be tricky, so I can use the screws that BF sent...

Cross yer fingers (and cross yer eyes, teeth, cross yer hair, piggies... :pray )

https://lh5.googleusercontent.com/-V...0/HPIM7502.JPG

Re: TOP END REFINISHING
 

3 hours, 5 Dremel bits ground to nubs.

Then I put on the Dremel cutting wheel, and cut a slot in the remnant on the front. Small screwdriver, and had it out in 5 minutes.

http://castletv.net/wp-content/forum...07/faint-1.gif

Shaft threads are spared. Shaft is still SNUG in the shaft bore (won't suck air).

Re: TOP END REFINISHING
 

I do not even recognize that ECM...My ECM has the four plugs in line and is black :D

I grounded the Secondary switch with a finishing nail along side the connector wire going into the plug without unplugging any of the four connectors :confused:

It only took me a few seconds to check the secondaries. Actually I had my buddy watch the secondary canisters through a couple runners of the Plenum each side with my remote wireless camera probe as I grounded the pin. He could tell they were not only operating but operating smoothly each time I grounded the pin on the ECM plug. We could also hear the vacuum pump kick on after a cycle to replenish the vacuum lost in the operation of the canisters as I recall ;)

Anyone can do this inspection/test without removing the Plenum. See Verifying Seocndary Operation with Plenum in Place by Marc Haibeck

Re: TOP END REFINISHING
 

The PCM in the image is a '94 - '95 MY only reprogrammable original to the LT1

Re: TOP END REFINISHING
 

Just about ready for a vacuum test...

But a question here (imagine that - I have a question http://www.zr1.net/forum/images/icons/icon10.gif ) : instead of putting the plenum down for the vac test, why not remove the [not yet] un-heat sink pasted DIS from underneath the plenum, plug it in alone, withOUT the plenum, and plug in the other peripherals of course, and do vac test withOUT the plenum in place? You DO need to be able to work the vac tubes, if you do have a missed / broken line...

https://lh5.googleusercontent.com/-4...0/HPIM7504.JPG

Re: TOP END REFINISHING
 

In your last image in post #334 you show a correct ECM but in your post #331 you've got a PCM from an LT1 in the image - care to explain? I didn't duplicate the images because of the size!

*** Never mind it's got an LT1 engine in the image also!!!

Re: TOP END REFINISHING
 

Correct there Dave - you know your vette mills :thumbsup: ; the old snappic was a '94 I did top end housecleaning a few years ago - just posted it to show ECM / PCM backprobe.

================================================== =============================

But now on vac test - everything plugged in dry, turned the key on, both fuel pump fuses pulled, and the secondary vacuum pump didn't come on.


Which connector did I miss here?

I still have some vac lines un-hooked as well - any of them necessary before sec vac pump trips on?

https://lh3.googleusercontent.com/-8...0/HPIM7505.JPG

Re: TOP END REFINISHING
 

the big tube is for the brake booster line and the small one I think feeds the input to the FPR.

Re: TOP END REFINISHING
 

The sec vac pump should turn on when the key is placed in the run position unless the switch inside the vac pump senses greater than 12" of vacuum which is not possible with every thing disconnected. There is an inline fuse of 10 amps for the vac pump. Check at the pump to see if wiring is disconnected or the fuse is blown. Check for voltage there.

Re: TOP END REFINISHING
 

It came to me last night - an hour after sackin' out - layin' there, thinkin' on it!!!

I did NOT plug in the forward 2 connectors on the DIS module. :o

Let's try it again, the RIGHT way...

Re: TOP END REFINISHING
 

Minor detail. NOT!

Re: TOP END REFINISHING
 

Still thinkin' on this throttle hesitation here...

If [since] 80% throttle opening comes from ONLY [ < 20%, actually] physical Range Of Motion OF THROTTLE LINKAGE ...

http://www.zr1.net/forum/images/icons/icon5.gif

https://lh6.googleusercontent.com/-D.../HPIM7334c.JPG

then EVERY operational parameter has almost 0 tolerance for deviation, from 0% Throttle Opening, to 80% Throttle Opening, when 80% throttle is reached in such a short span.

There HAS TO be some 'buffer' integrated into all parameters' sync'ing properly; otherwise, every 1 year-old LT5 with even minor hardware degradation is gonna' have some problem...

such as 'Off-Idle Sag'

unless the potentiometer in the TPS has some buffer mechanism built-in, such as logarithmic resistance, and not linear (never mind just now that FSM says that the TPS Voltage response is linear..................... )

This make any sense to anyone?

Re: TOP END REFINISHING
 

Yeeeaaaah.... It might cause a "hesitation"..:confused:...:censored:

Re: TOP END REFINISHING
 

O...K...

So plug in the 2 forward DIS module connectors, and turn the key.

No sec vac pump. And why do I have fuel pressure, with both FP fuses pulled?

No, I don't have both FP fuses pulled - #2 FP fuse is in, on the UNDERdash Aux fuse block - the 10 Amp fuse on the end of the block, and the 10 Amp fuse on the OTHER end of Aux fuse block, for 'CRNK-A/B' is pulled OUT. :censored:

Switch them, turn the key, and no sec vac pump. :censored:

:confused:

:censored:

Back to the FSM drawing board...

Re: TOP END REFINISHING
 

2' vac pump diags.

Test the ground at the 2' vac pump fuse (please be bad)

nope

https://lh6.googleusercontent.com/-V...0/HPIM7509.JPG

Fine ( MF'er :censored: )

Power comin' in?

https://lh6.googleusercontent.com/-6...0/HPIM7510.JPG

Re: TOP END REFINISHING
 

OK it looks like you have the voltage to the fuse on the orange wire... The blue wire should go to the vac pump. Maybe jumper across the terminals to see if the pump runs?

Re: TOP END REFINISHING
 

I thought about that, but the pump ran fine before, and the battery was un-plugged from before wrench 1 turned a bolt.

So test for a good ground, and good power.

Then what I saw comin' IN bothered me.

Isn't 11.77 V reflective of a problem? Cause it sure wouldn't drive the pump...

I went to FSM, and schematic shows 12V from IG Switch, to splice S239 near Cruise Control Module, P side UNDERdash, and from there, to

1) 2' vac pump, through fuse,
2) Power Window Circuit Breaker @ Main Fuse Panel, and
3) A/C Fuse.

My plan was to test for identical 11.77 V @ '2', and '3', and then work back to IG Switch OUTput, and see if it ALSO was out-putting 11.77 V

But the best laid plans of Schrade & men oft go awry. And this job is in regression, with a decay rate seeming exponential in proportion.

The IAC connector gasket fell off. I unbolted the TB to look, and now 1 of the nuts from the TB linkage / cam shield fell off. It's not in the induction port, but now that I thought longer on the IAC gasket, there is the most remote of possibilities that IT found it's way into #2.

Re: TOP END REFINISHING
 

I'm thinkin that your dropping about 1/2 volt or so between the battery and the fuse connection through the ign switch and wiring for the vac pump. Possibly a slightly resistive connection but I would make sure that your battery is fully charged since you were doing fuel pump testing and they draw at least 4 amps each I think. Also, since that vac pump ckt is separate from the DIS module I don't see why the pump shouldn't run. In theory if you put 12V on the dk blue lead to the vac pump with the fuse connector off she should run.

Good job finding those 2 parts. There are so many nooks and crannies on these motors that people have lost small animals and ratchets and.... and...