Just bought an 84, needed a new fuel injector to get it going, now it idles very high and i noticed the front passenger pipe red hot and exhaust flowing from the connection......clogged cat? options? dangers?

 

did you put in the right fuel injector for a crossfire ?

 

Not likely a clogged cat since BOTH sides share the same cat...and both sides weren't glowing, were they?

High idle = vacuum leak, typically.

 

On my '84 I had to remove the intake manifold and when I put it back together I set the distributor in where it was but didn't have a timing light handy and since it started up I let it run for a while and the exhaust manifolds started to glow red in the centers. When I put a timing light on it I found the timing to be very retarded. I set the timing correctly and the glow went away. Be sure to unplug the EST connector next to the brake booster and then set timing at 8 to 10 degrees advanced rather than the 6 degrees called for in the FSM.

 

I did use the right fuel injector, I also noticed exhaust coming from the connection between the manifold and the exhaust pipe. This is what made me think something is blocked. I just got the car and have never been underneath it so I have not inspected the exhaust system. It needed the fuel injecto to even run which was today's project

 

Ok, so let's say I missed a vacuum line putting the top back on after the TBI change. I get that this will cause the high idle and I very well may have done this. Will it cause the excessive heat issue?

 

Possibly...but not probably. If the leak was able to affect one side meaningfully more than another side, then yes.

I'd also check timing as danlb suggested...although that would typically affect both sides.

 

Call Jon at FIC and get a good deal on a set of injectors check your timing and see if your harmonic balancer is separating and has moved. And very well might be pluged as well. And a leak will throw off your o2 and in turn your fuel.

Welcome to the forum.

 

Wait, one primary tube, or all 4 primaries? Are you sure the other side wasnt starting to glow too?

hot exhaust doesn't necessarily mean vacuum leak, it means lean. generally, lean means vacuum leak but not always. Usually, the motor runs in closed loop mode and can compensate automatically for a lean condition by adding more fuel. However, while it is warming up it is in open loop fueling mode and has no way of knowing it is lean.

The other option besides a vacuum leak is that the IACs (Idle air controllers) are wide open, which is likely if any sort of work has been done on the Throttle bodies recently. (sounds like it has). The IACs can be automatically reset by driving to 45MPH for a few seconds (its actually that simple) This problem would also be temporarily compensated for by closed loop mode if it had time to warm up enough to get there, but I dont recommend running it long enough for it to go closed loop if the exhaust is that hot.

If its just one primary tube it might be an incorrectly adjusted exhaust valve, I think. This would result in a ruined valve if the motor was used without correcting the issue.

Good luck and welcome to the forum

 

I would put money on it being the IACs. It happened to me before when I changed the intake manifold my headers started to dully glow while setting the valve lash. I was worried about a vacuum leak, but it turned out to be the IAC motors for me.

 

Not to say you're wrong. Red hot headers usually mean a rich condition as the fuel is still burning out the exhaust. Such as a greatly retarded timing would also cause.

 

I had heard that both lean and rich are possible causes of the overheated exhaust, but it would have to be extremely rich to do so wouldn't it?

 

^^ I have had one occurrence of a rich condition that lit up the left bank on my 86.
This was retarded timing related. So to say "extremely rich" is very subjective.

Maybe another can chime in...