Pulling the intake on my '82

[wishuwerehere82]

82 L83 Pulling the intake manifold.

After dealing with a missing cylinder sometimes and sometimes not, I decided to pull the intake manifold and see if a new gasket set would make any difference. I was seeing only about 10" of vacuum at idle and it wasn't very stable.
Heidi and Kenny's latest engine experience has motivated me to dig into the guts to figure out what the problem is.

2 1/2 Hrs later I stripped everthing off to get down to the heads.
So far I think I have found a bad seal at the top plate gasket and possibly and bad seal between #2 and #4 intakes. The bolts at either end of the manifold that are next to the water jacket ports are really looking burnt or corroded. I am going to tack the manifold gaskets with FelCo Bond and seal the manifold ends with Permatex ultra black RTV because there are no end seals like they used to include in the gasket kit.
Is there a preferred sealant or threadlocker for the manifold bolts that is better than another? I have some blue Loctite 454 that seems too runny to make a good seal.
I hope this cures the problem because power without control does not make for a good driving experience.:confused
Any suggestions would be appreciated. I have done this job before, but there is such a wealth of knowledge here at CAC I can't help but ask.

 

[wishuwerehere82]

Never mind. I'm finished.

 

[78SilvAnniv]

How does it run now?

I just showed this thread to Kenny and he wants to know how it runs. Ours was sharing 2 and 4 cylinders because of the first gasket slipping. We hope we've fixed that problem, but if it occurs again, I am buying differrent gaskets than the black ones with blue lines.
We found that those gaskets' bolt holes are very large. Larger than the diameter of the actual bolts that hold them, so it would allow the gasket to slide around when placing the manifold, which is what we think may have happened during the first installation.
Second time around we put on dots of adhesive to hold it all together...but I keep thinking about it and can't get it off my mind... If the manifold comes off for any reason, I'm replacing those gaskets with ones whose bolt holes are actually snug with the bolts.
Heidi

 

[wishuwerehere82]

Hi heidi,

I used Fel pro gasket (the blue ones) on the manifold and I also had large bolt holes. I tacked it in place with Felcobond contact cement and made sure to line the gasket bridges with the centers of the intake ports and let it set up before assembling the manifold. I had a lot of corrosion pitting in the aluminum around the water jacket ports that took a lot of scrubbing to get cleaned up so they would seal properly and not leak.
I am waiting until tomorrow to fire it up so that the silicone on the ends gets fully cured. I checked it a little while ago and the squishy spots are firming up nicely. I will let you know what happens after resetting the timing and going through the adjustments tomorrow.
I hope it works well enough to drive to Carlisle, PA. at the end of August for Corvettes at Carlisle.
Thanks for asking. How's your's driving now?

Pete.

 

[78SilvAnniv]

How's your's driving now?

She seems to be stronger than ever!
It appears to me that I am attaining faster speeds at lower rpm levels. She doesn't expend very much energy to reach our cruising speeds, and I have NOT stuck my foot into her yet!
I am begining to be afraid of what will happen when I do. :eek Seems like it would be very easy to burn rubber now.

However, I think we still have some 'bugs' to work out...
Our choke keeps sticking, and yesterday evening when I went to pick up dinner she seemed to be running 'rough' and possibly missing (thought of the manifold gaskets...) but when I pulled into the garage and told Kenny, he took off the air cleaner top and fiddled with the carb (choke again?) and she smoothed right out.

Looks like either a new carb or rebuild of my original is in order.
Heidi

 

[Jack]

which cam Heidi?

She seems to be stronger than ever!
It appears to me that I am attaining faster speeds at lower rpm levels. She doesn't expend very much energy to reach our cruising speeds, and I have NOT stuck my foot into her yet! I am begining to be afraid of what will happen when I do. Seems like it would be very easy to burn rubber now.Heidi

Heidi:
Sounds good! Do you recall exactly which cam (mfg-P/N) y'all went for?
JACK:gap

 

[78SilvAnniv]

Hi Jack,
Crane Energizer 272 H10
216I, 272E w/ .454 lift and 110* lobe separation

My parts store Manager recommended an Edelbrock carb to me, list is $250, he said he'd sell it to me for 25% off. Good deal?
It looked pretty and shiny!
Heidi

 

[wishuwerehere82]

Heidi and Kenny,

Well, it runs better than before.. but still misses ocasionally.
I ordered some silicone wires, wire looms and splitfire plugs today. I hate to shotgun every component on the engine, but I am finding that nobody knows more about the L83 than I do...at the moment. I took it a "Mechanic" Wednesday and all he said was that I had low vacuum,hence the new manifold gasket. No engine analyzer, no scanning for codes, nothing besides hooking up a vacuum gauge and then left my air cleaner out in the rain.
I drove out to airport to watch the Blue Angels for a little while today and actually spun the tires for the first time in years. EEEE-Hah.

Pete.

 

[MoeJr]

Pete if ya were a little closer to me I could hook you up with the guy that set my L83 up. He has mine running like a champ. These cross fire cars are really good runners when they are all tuned and set up. With the wires I would change the coil and ignition module along with the cap and rotor if you haven't already. Some of the GM rotors used to start burning thru and would ground to the igniton shaft. Hope this helps.



Moe

 

[wishuwerehere82]

Moe,

Thanks for the reply.
I have blue streak cap and rotor with a replacement GM coil and am on my 3rd set of wires and plugs since the rebuild 23,000 miles ago. All new sensors, TPI,MAP,KNOCK,TEMP,OIL PRESS,IAC's.
The TBI's have been balanced more times than I can recall, and it doesn't seem out of balance.
Something tells me that a new Advance module is needed, because the timing is not holding steady at idle with the advance disconnected. When I first started it, the idle went up and down and the timing was jumping back and forth about 15 degrees. I shut it off and started it again,and everything was solid! I then set the timing at 6 degrees BTDC and reconnected the advance. After about 5 minutes on the road, everything seemed normal. It idled at 650 RPM and I took it for a drive. Shut off for bout 1/2 Hr. and started it back up, it was stumbling again until I got on the highway and took it up to redline. Everything turned back on again and ran fine when I got home. I waited about 3 Hrs., started it back up again and took it to the corner store. All cylinders firing great, but it wouldn't idle down and was running at 1000 RPM the whole time.
Weird Huh? If it would stay constant for a while I could figure out what the dang deal is with this thing!
I'm almost thinking of pulling the ECM and resoldering all of the components on the control board. Is that extreme or what?
Thanks for the help everyone.

Pete.

 

[MoeJr]

Definietly try a new module. If you wanna test ecm just tap on it with the handle of a screwdriver. If the car starts to act funny you know it has some loose connections. Also you may wanna bump the timing 2 degrees to 8 BTDC. I would prefer to see you put in a GM module if possible. Keep us posted. We'll get it licked.




Moe

 

[Jack]

Hi Jack,
Crane Energizer 272 H10
216I, 272E w/ .454 lift and 110* lobe separation

My parts store Manager recommended an Edelbrock carb to me, list is $250, he said he'd sell it to me for 25% off. Good deal?
It looked pretty and shiny!
Heidi

That's a step up from RV for sure. Carb at that price ... assume it is Edelbrock 14XX or 18XX series carb ... probably a decent price ... but if it is 14XX / 18XX series ... they have SQUAREBORE mounting flange ... and do not fit most sbc OE intake as your OE intake almost certainly has only SPREADBORE mount flange to match Qjet. 14XX is a clone of a Carter AFB. At his price my guess is that it's a remanufactured E'brock clone of an AFB.

Edlebrock does make a 19XX series carb that is a clone of Rochester Qjet. The Qjet clone typically costs about 70% MORE than AFB clone.

Edelbrock also markets remanufactured versions of their carbs ... a reman E'brock AFB clone w/electric choke at Summit about $225 (new $267) ... Summit's reman E'brock Qjet clone about $400 (new $460).

Summit sells JET's expertly blueprinted Rochester Qjet for $350 ... they're used but better than new after blueprint. Summit sells they're own reman Qjet for about $295.

I haven't bought a thing from Summit in years ... but use it as reference because alota folks do have their catalog.

You might wanna take a close look at whether your carb choice(s) will bolt right up to your intake (without adapter plate). Frankly, for street use it's VERY hard to top the performance of a good Qjet or its clone ... they have small primary bores for good idle thru mid-range throttle response but BIG secondaries for top end ... a very good balance for street. Qjets flow a minimum of 750 cfm. Squarebore carbs have same size primary & secondary bores. Not that I recommend (I don't), but one of my sources lists reman E'Brock AFB clone 600 cfm w/ manual choke (P/N 9905) at $181.25. If your parts guy will sell you a E'brock Qjet Spreadbore clone (new or reman) for under $200 ... snap it up!

BTW, with age ... Qjet float often gets "gaslogged" (heavy) and carb goes intermittantly rich ... that niggling can drive you nuts. You can get a new float at parts house for less than $20. Lift the lid on Qjet & blow it all out with a $1 can of carb cleaner ... Put in a new float ... CAREFULLY relocate the metering rods and button it back up ... you don't even have to take carb off intake to do it ... 30-45 mins total ... I'd try that first. I can only guess Kenny's level of enthusiasm if faced with another intake swap to match AFB ... and then having to rig a fuel line/linkage/choke. We can't see the shine with the breather on ... but you'll sure know if it performs.
JACK:gap

 

[78SilvAnniv]

I started a new thread in C3T&P Forum about my carb questions so I wouldn't hijack 82's thread any further.
Heidi

 

[wishuwerehere82]

Not a problem, Heidi.

I like reading Jack's postings. I have a carbureted car too, and who knows when I might need a new carb.

Pete.

 

[wishuwerehere82]

Definietly try a new module. If you wanna test ecm just tap on it with the handle of a screwdriver. If the car starts to act funny you know it has some loose connections. Also you may wanna bump the timing 2 degrees to 8 BTDC. I would prefer to see you put in a GM module if possible. Keep us posted. We'll get it licked.




Moe

Moe,

I went to the Chevy dealer and he said they were discontinued, but pointed me to Meizensahl's auto parts that had them in stock. While talking to Charlie at the desk, I told him of my problems and he offered to put a diagnostic scanner on it after work on his own time.
He advised me not to put in the new module until we had a chance to check it out first.
We met at a diner parking lot and he plugged it in and guess what? There are no codes stored! Nothing!:confused
We put it in active mode and monitored the ECM and it is running open loop for most of the time. It went into closed loop once and smoothed right out, but a few seconds later it went back into open loop again and stayed there.
The readings we were getting were:
Prom # 9531
Temp= 195 degrees.
O2 went from .53V in closed loop to 0 Volts when in open loop.
O2 cross count=none 00V
IAC motors went from .17V in closed loop to .007V in open loop.
Map sensor= 10" HG at 1.44V in open loop.
Knock sensor= 0V in open loop.
TPS sensor= .56V in open loop.
Timing= 9.5 degrees in open loop.
The mixture alternated between rich and lean while we were monitoring it in open loop and most of the usual stumbling and oscillations were observed.
Needless to say, this was a real eye opening experience.
It seems to me that I have an intermittant open circuit on my O2 sensor somewhere or a bad new O2 sensor. My new sensor came with a new connector that I think I will splice in, in light of this new information.
Or a bad connection inside the ECM somewhere.
Any ideas? My brain hurts!

Pete.

 

[wishuwerehere82]

I'm going to start a new link for this, seeing it doesn't have anything to do with my manifold anymore.

Thanks for all the help everyone! See you at the new link entitled " '82 Cross-fire running open loop".

Pete.

 

[78SilvAnniv]

You can delete replies # 17 & 18 and still begin the new thread.
Interesting problem you found and I hope it is easy to resolve.
Heidi

 

[jdp6000]

Pete,

I have an 82 Vette. I'm about to change the 2 TBI gaskets and the throttle plate gasket. did you do this also. Anything I should watch for??

Jim

 

[wishuwerehere82]

http://www.crossfire.homeip.net/
I replied on Twinnies forum, since this one was down for a while.

 

[jdp6000]

Pete,

I can't find this Twinnies forum. Where is it?

Jim