heat and miss problem

[93grnbird]

ok guys im new to the site and had to get rid of my old 68 400 firebird at the beginning of this year (money problems) but about a 3 months ago i bought a 93 firebird formula and been having some problems and wanted to see if anyone could help 1st is the car is overheating and i have no heat so i checked the anti-freze it was good unlees there is a overflow which i did not see and i thought there might gave been a air pocket so i bleed both of the bleeders and it was a cheap part so i changed the thermostat and it continues to overheat it would go to 240 and both fans would kick on and go right back down to 130 which is what it runs at while im driving im sure thats not what it should run at being i put a 180 in it

2nd a few days after i got the car i was on my way up the hill by my house and it started missing really bad almost didnt make it up the hill to my house so i thought it may have been the plugs so as i was taking them out there were different ones and all gaped different and 1 was loose enough to take out by hand so changed them all it ran fine up untill yesterday this is not my daily driver and it spend alot of time in the garage it has 59k mile i dont think its anything mager but hope someone has a idea what to do and thank you for your time

[93grnbird]

ok now i took all the hoses off and flushed everything there was sludge that came out and changed the plug wires and took 1 off at a time so i didnt get them mixed up and now it will not start

[Joe 1320]

http://www.f-body.com/forum/showpost...4&postcount=17

http://www.f-body.com/forum/showpost...1&postcount=18

[Injuneer]

A thermostat for an LT1 is not a "cheap part"..... or did you just get the standard t'stat for a Gen 1 SBC? Won't work right. You need a 'stat specifically for the LT1.

Sionce you have a 93, and the coolant temp gauge is incorrectly marked (compared to 94 and up), your car is not actually running at 130*F. If it was, the computer wouldn't go into closed loop, your idle speed would be elevated due to low coolant temp, fuel mileage would be poor, etc. If you compare the 93 gauge to all the other years, you'll see that you are probably running at about 185*F.

http://shbox.com/1/temp_gauges1.jpg

[93grnbird]

thanks joe followed the steps and found out it was the distributer and was not spark at the plugs no just need to find out how to get that damn crank pully off to get to it

[93grnbird]

and injuneer im not sure what thermostat i got for that i went to auto zone and needed 1 for the 93 formula v8 and not sure what a sbc is but thank you for the gauge pics i would have never guessed that my gauge was of and looking at the pics it would have been about 180 or so but have to get a distributor first to see if the fulsh has worked also would you know if there is more than 2 realys for the fan because i think something is wrong there too as far as i know 1 should kick on at about 200 or so and it doesnt it would wait till 240 which i know is a unsafe temp and then they would both kick on if you have any ideas i would appreciate it my uncle would help me with everything car wise and im on my own now he past away a few years ago also that is 1 sick bird you have

[FTA1995]

...just need to find out how to get that damn crank pully off to get to it

18 inch breaker bar does an excellent job breaking all the large bolts you'll encounter on an opti job. Don't pull the crank HUB, just unbolt the pulley and give it some gentle tapping to get it off

Also, Fred;
The older gen sb's use a thermostat with a wider restrictor on them that doesn't fit into the lt water pump housing correctly, right? I was thinking about replacing my cheapo 160 for one made for our gen, worth it?

[FTA1995]

.. if there is more than 2 realys for the fan because i think something is wrong there too as far as i know 1 should kick on at about 200 or so and it doesnt it would wait till 240 which i know is a unsafe temp ...

There are two fan relays, both in the underhood junction box. If you do not find an infrared thermometer or thermocouple so you can accurately gauge your operating temp, figure out if it's a bad temp sendin unit or if your overheat condition is real.

[93grnbird]

ok thanks i'll check into the fan problem and let you guys know how it turns out and i really appreciate all the input guys thanks

[Z Ya Later]

...and give it some gentle tapping to get it off

Or you can just spend a few bucks, get a puller and make it real easy.

Also, Fred;
The older gen sb's use a thermostat with a wider restrictor on them that doesn't fit into the lt water pump housing correctly, right? I was thinking about replacing my cheapo 160 for one made for our gen, worth it?

In a word, YES!!

[Joe 1320]

thanks joe followed the steps and found out it was the distributer and was not spark at the plugs no just need to find out how to get that damn crank pully off to get to it

The crank pulley bolts to the hub with 3 bolts. Only the pulley need be removed, the hub is a press fit on the end of the crank snout. Once the pulley is unbolted (use a big rubber hammer to tap it loose) the crank is rotated by hand so that the hub is oriented in a Y shape. the top bolt holes should be moved to the 10 and 2 o'clock position and one hole is in the 6 o'clock position. This will allow the optispark to be removed without removal of the hub.

[93grnbird]

also i belive its the water pump from what i can see it looks like it sits behind that too so does that have to come off not starting till saturday so if anyone knows it would be alot of help

[sneitzel]

Yes.
You do have to remove the water pump along with the cooling fans and a few other misc items, AIR pump and coil if my memory serves, to replace the OPTISPARK distributor.

Personally, I found it easier to pull the radiator as well just to give some extra room while working in there but that is technically not necessary. Since you just did a flush, definitely save and reuse the coolant. If the hoses are original I think I'd replace them too while you're in there. 2010 - 1993 = old hose with something bad just wait-ing to happen. If you do pull the radiator, be extra, extra, extra careful with the low coolant sensor on the side of the radiator. They are notorious for going bad for no reason and bumping it around during radiator R&R can definitely cause them to fail. Nothing is more frustrating than getting everything back together, tight, bled, no leaks and running great only to have the low coolant light flicker on.... With the radiator out, would be a good time to make sure as much sludge as possible is washed out of it as well.

The "No Heat" issue would also suggest that the heater core may be plugged with sludge as well. That's not too difficult to change either, just maybe tackle the OPTI first and get her running again then worry about heat.

[93grnbird]

thanks a lot guys with all the info and tips you guys gave me everything went really easy with no problems and didnt have to pull the rad with the fans out of the way i had plenty of room and this part is not cheap i did find 1 at a junk yard but i really dont want to do this again i found a msd for 475.00 anyone know any better or cheaper i know you get what you pay for but let me know if anyone has a link

[Injuneer]

Also, Fred;
The older gen sb's use a thermostat with a wider restrictor on them that doesn't fit into the lt water pump housing correctly, right?

It will fit in the hole, but it won't work right. Shoebox has additional infor:



FOR THE ORIGINAL POSTER: SBC = small block Chevy. The first 40 years of the SBC were basically the same, and are call "Gen 1". The LT1 has several major changes, including the Optispark distributor and "reverse flow" cooling. The LT1 is called a Gen 2 SBC. As a result of the differences, some parts, including the distributor and the thermostat do no interchange between a Gen 1 SBC and a Gen 2 SBC.

I was thinking about replacing my cheapo 160 for one made for our gen, worth it?

Not just worth it - mandatory.

FOR ORIGINAL POSTER:

There is no reason to buy the expensive MSD distributor. Find an OEM GM part (AC Delco, or now Delphi).