attroll

I just recently acquired a 1989 firebird. It is a tune port 350. The previous owner put headers on it and a new exhaust. It runs really rough right now, but I am getting some wires and plugs tomorrow and will be tuning it up. But that is not the problem I am having.

After the engine is started and runs at idle for a few minutes the headers around all exhaust ports start to glow red. I have owned headers on beefed up cars before but I have never seen the glow red like this and so quick. This does not seem normal.

Is this normal and if not what would cause it?

Danny2tek

iTrader: (1)

both sides?

Formula350

iTrader: (3)

I can't remember if that means it's running lean or rich. I'd replace the O2 sensor as well since that's probably junk.

Is that normal on a relativly stock car just idling, nnnno

attroll

Yes on both sides.

Mohican

The timing might be retarded and causing the headers to glow. I have a friend with a 71 Olds 442 and we recently rebuilt the motor and when we fired it up for the first time to break in the cam the headers were glowing like yours. Since the car has a distributor it was easy to correct the problem. I'm not sure about your car but it is a possibility.

Rothman

iTrader: (4)

Could be lean. LEAN=HOT=BAD for car

attroll

Thanks for all the replies. I have not had time to put the new wires and plugs in yet and do the timing. I am hoping to do it this weekend if the weather cooperates.

EchoMirage

iTrader: (3)

My friend has a 72 455HO Trans Am. His manifolds have been glowing for years, and he can't find out why, after doing nearly everything. He says it all started when he left the key on ignition while doing work for a while, with the engine off. Do the plugs, wires, check timing, and it might also be running rich. Also think into getting a new harness. When my friend finally did that, the glowing went away. At least for a while.

warp_6

iTrader: (2)

Check the cats. Make sure there not plugged.

attroll

Warp-6, there ate not cats on this.

Here is the update of what I have done so far. I put new wires and plug on it but have not started it yet to see if it has fixed it. The reason why is because I was looking at the way it was wired. Here is what I have for the firing order the way it was wired, 1,2,7,5,6,3,4,8. That would be fine if this was a 307. From what I read is that the 307 is the only engine that has the rotor that spins clockwise. I have been told that the 350 spins count clockwise. if that is the case then the firing order should be 1,8,4,3,6,5,7,2.

Before I start this and try to time it. What is the proper firing order and which way does the rotor turn?

SINISTER-TA

iTrader: (3)

"307"??? I think you mean 305. The 350 and the 305 have the same firing order. The glowing red manifolds/headers means that it's running lean.

attroll

Your right I think it is suppose to be 305 and not 307. Here is where I got my information for the firing order and rotor rotation http://boxwrench.net/specs/pont_265-455.htm.

My son went and bought a book tonight at the automotive shop and has it at his house. I will try and get it and look at it tomorrow.

The only reason I brought up the firing order was becaused I look at the web site I meantioned above and it does not match what we have.

SINISTER-TA

iTrader: (3)

That site is refering to older Pontiac engines. The 350 TPI engine in your Firebird is the exact same engine that was used in the 89 Camaro. The L98 Chevrolet small block. It uses the HEI (High Energy Ignition) sytem.

Your Engine,

Firng Order: 5.7 (350): 1-8-4-3-6-5-7-2 (Rotation Clockwise)

(top view of engine firing order)

8 7
6 5
4 3
2 1

(Front of engine)

Ignition timing should be set at 6 Degrees BTDC.
Spark plug gap: 0.035
Fuel Pressure should be at 40-47 psi

Hope this helps.

attroll

We worked on the car today and here is where we stand.

We checked the wiring and all was good.

We set the time to what we thought was 6 Degrees BTDC, but we found at 6 degrees BTC it was still backfiring when you stepped on the gas, so retarded it more. We brought it back about 6 more degrees, which allowed us to step on the gas without it backfiring. It does have a little hesitation when you step on the gas but it is not backfiring now. I will try and draw a makeshift picture of the timing marks below. I hope you can it can be understandable (I had to put dots in it to make the spacing work). If this does not make sence I can draw out a picture and scan it to explain it better. Just let me know.

--------------
!........../\.....!
!_/\/\/\/..\/\_!
....!.......!
....!.......!
....!.......6 degrees BTC I think
....!
....working without backfiring

We did not have a chance to let it run to long to see if the exhaust was still glowing, but so far we have noticed a big improvement in the running.

I have two questions though.

Q. #1, Should I try and retard it even more then I have now to see if the hesitation will go away?

One other thing we noticed when we were working on this today. The air return line from the catalatic converter is not hooked up. We called the previous owner and he said he gutted the converter and plugged the line coming off the converter. The line coming from the engine is just attached to body and hanging there.

Q. #2, Should we hooked that back up or leave the lines plugged?

SINISTER-TA

iTrader: (3)

Check the fuel pressure and make sure thats ok. Check the fuel filter and make sure its not clogged. Pull out the O2 sensors and make sure they are good. As far as the Cat goes...it shouldn't make much difference as long as it's not clogged up. I would replace it or get rid of it in favor of an off road pipe. Make sure that the distributer isn't off by at tooth or two. An engine can still run when this happens...just real bad. Find out if the last owner pulled it out at some point in time.