My cat runs red hot. Is this ok or am I running rich or something or is this normal. I'm running a 305 computer controlled quadrajet. It's a new cat but I'm worried I'm ruining it running so hot. Please help and answer my question as quick as possible thank you.

 

It will get hot... really hot... but glowing is somewhat excessive. You are likely running rich, or the cat is clogged (but yours is new, so likely not the case)/

 

What he said ^. It should not be glowing.

 

Yep glowing is too hot. But they will normally reach in excess of 600 degrees. I've burned my arms more than once...

 

yep It's glowing. I must be running rich. Just what I thought. Thanks.

 

Or you are running too much timeing .

 

The base timing is 0 degrees. Is that too much? I tried to adjust the idle mixture screws like the book said to turn till seat then back out 3 turns I ran it till it was in closed loop then tried to turn them in till the rpm dropped then back them out till max rpm but it didn't do anything so I left it at about 2 turns in.

 

should be 6 * BTDC

 

Ok I changed it to 6 it runs alot better but the cat still get's red not as bad but a little spot above the air tube get's red hot is this ok or am I still running rich? I tried to do the mixture screws again but still no change in rpm to know if I'm adjusting it right or should I adjust it a differant way? I have the screws out about 2 turns right now should this be close?

 

The converter glows red because you're way to rich or has incomplete combustion. A clogged cat will glow red but the car will run really bad rpm wise. The most problems ive seen when a coverter was glowing red was becasue it had a missfire or the plugs were shot due to nitrous also you want to make sure you dont have any vaccum leaks as this will do the same thing in some cases.

 

The car does pop real loud sometimes what could cause that?

 

Well if the poping noise is comming out of the exhaust it means your way to rich. If the poping noise is comming threw the intake your way to lean (vac leak or horribly miss adjusted) If i were you i would make sure the plug wires are not arching and that the plugs are in good condition. Do a scan and make sure all the vac hoses are hooked up. Their is also a possiblity that the coil is going bad hints missfire. Before messing around with the carb. On another note If changing the timming made such a huge improvement you might want to go back and make sure everything is where it is suppose to be. I have no idea why the timming would be set to 0 degrees. This might just be a case of everything has been tampered with and needs to go back to so called stock settings.

 

You also may not have any timing advance. retarded timing can cause the buring to continue thru down to the cat. Check to make sure that the advance system is working.

 

The popping is comming out of the exhaust.I had timing set to 0 because that's what it said on the underhood sticker. I know I'm running rich but I'm having a hard time setting it right. I do have a snap on scanner that tells me the mc dwell has been running at about 10 degrees at idle and about 36 at 3000 rpm. I'm not getting any codes and the oxygen sensor seems to be working right and it goes from rich to lean on a regular so I'm wondering what next. Change my O2 sensor or what? I need to adjust the idle mixture screws I need to know the approx. # of turns they need to be out. I also need to adjust my Idle air bleed I need to know the number of threads on that. I think I have the mixture control solenoid set right I set it to the 1.304 lean hight and I left the rich alone and I have the 4/32 of travel so what am I missing?

 

hey man, if advancing it helped, check you vaccuum advance on your distributor. It might have crap in it. Also, bump up your timing a little. I have a tpi so im a little different but on 93 octane I have a 15* advance. The popping noise is the fuel exploding in the manifold.. if you have a really high of an advance such as mine you will get that in the upper rpms when you let off the throttle. If you have too low it will just leak out the valves. Lean out your mixture and advance it a little.. if you have to run a lower octane assuming your running mid or premium.

 

10 degrees means low voltage, which means the computer is keeping the solonoid up longer, which means richening the carb to adjust for a lean condition. 36 at 3000 is good. The solonoid adjustments are for high RPM. The Idle mixture screws are for adjusting dwell at idle. Get the idle dwell to read the same as the high RPM by adjusting the mixture screws a little at a time. There is no set # of turns. The O2 reading rich and lean means the computer is seeing that the dwell is controlling the mixture, at least it thinks it is. Put a rag over the carb and see if the RPM increases, and watch the O2 reading. If the RPM increases, you're running lean. The O2 reading should go above .8volts and stay there if the rag causes it to run rich. You need to create a rich condition to ensure the O2 is reading OK. As far as timing, you may need to pull #1 spark plug and get the cylinder to TDC. Double check the mark on the Dampner is within a few degrees of TDC. If it's off, make a mark at TDC and use that as your reference point. If it is off, the mark will advance and cause you to adjust it too low thinking it's right. Check the scanner to see if there is a timing advance line. At idle it usually advances around 11 degrees with the timing connector connected. The idle air bleed is another adjustment. There is a special tool to adjust it. Most of the ones I've done are usually around three to five threads, but it needs to be proportional to the M/C solonoid lean stop adjustment.

 

Also, remove the idle air bleed valve and check the O rings. If they are flat, and you'll be able to tell, they will need to be replaced. Any carb rebuild shop should have them fairly inexpensive. If the O rings are bad, you will never be able to adjust properly.

 

Ok I think I got it. First, there was a vacuum leak. The big hose that goes to the canister control valve had a split under it that I couldn't see I fixed that and I was able to adjust the mixture screws enough to get the dwell at Idle to about 30 and I don't think the cat gets red anymore. I did this in drive is that right? I couldn't get the dwell to move in park. It still pops once in a while but I think it's because there is no cat back exhaust on it. I tried to set the base timing to 10 but it's hard to start so I put it back to 6. I think It's going to be ok now not perfect but better. The mixture screws are out about 5 to 6 turns I think. Is that ok? I'll let you know in a couple days how it's doing.

 

Hi,

If having a hard time setting the idle mixture just hook
up a vacumm gauge. Start the motor up and back in the
screws one at a time until the motor starts to stumble.
Slowly back them out one at a time until you get the highest vacumm reading. Will have to go back and forth
between them until you find the spot.

HTH

jaykar

 

Ok I'll try that but first I'll have to buy a vacuum guage. Thanks.