This is topic Cat glows when car is warm in forum Tech Talk at Northern California Ford Owners  .


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Posted by 1SLOWLX (Member # 558) on :
 
My cats on my bbk H-Pipe glow red after the car is warmed up. I know there is no leaky injector because they are brand new. When the car is cold it runs great but when it gets hot it has like a choking affect on it. Do you think the cats are bad? Should I just beat them out?
Albert
 
Posted by JUSTIN (Member # 586) on :
 
check your timing andair fuel, maybe vac leak??
 
Posted by Platinum Pony (Member # 970) on :
 
lol
sorry just checkin something
 
Posted by st5150 (Member # 51) on :
 
Too much timing retard or too rich of an air fuel ratio will cause the catalyst to work extra hard to burn up the extra fuel before it goes out the pipes, thus making it glow.
 
Posted by 1SLOWLX (Member # 558) on :
 
But the car also feels like it lost power when it is warm. Do you think if I beat the cats out I won't have the choking effect anymore. I am going to take it back to the dyno later but right now I want it to run good first. The mods are a 347 s-trim motor with 50lb injectors no fmu and a aeromotive comp fuel kit. Do you guys think it will run better with no cats? I think one of them are clogged
Albert
 
Posted by st5150 (Member # 51) on :
 
Yeah, it will make more power (and be louder) with no cats.... but thats not your problem... your problem is that its running extra rich when it warms up... causing you to lose power and over work your cats. Do you have a custom chip for your setep? If not, your combo is begging for one.
 
Posted by 1SLOWLX (Member # 558) on :
 
I have a custom chip for right now from bryon. The cats still glow red when it is hot. I am getting really tired of this car.
Albert
 
Posted by st5150 (Member # 51) on :
 
quote:
Originally posted by 1SLOWLX:
I have a custom chip for right now from bryon. The cats still glow red when it is hot. I am getting really tired of this car.
Albert
How do your plugs look?
 
Posted by 1SLOWLX (Member # 558) on :
 
I am going to put in the autolite 3923. Right now I have the wrong length plug in the car. Do you think that can be the problem? Also do you think it can have a leaking injector?
Albert
 
Posted by st5150 (Member # 51) on :
 
Well if your plug is so short that its preventing a complete burn, it could possible cause extra unburnt fuel to enter your cats and cause them to glow. Kind of a slim chance though. If you have an injector hung open or something (also very rare), it will show when you pull out your existing plugs. A vacuum leak to your fuel pressure regulator will also cause you to run rich all the time.
 
Posted by 1SLOWLX (Member # 558) on :
 
What about if the fuel pressure regulator was clogged or had some dirt in it?
I have the aeromotive comp kit and ran the vaccum line off the manifold to the regulator so I don't it leaks. But the lines were kinda dirty when we put them on. (You know about these steel braided fuel lines)
Albert
 
Posted by st5150 (Member # 51) on :
 
quote:
Originally posted by 1SLOWLX:
What about if the fuel pressure regulator was clogged or had some dirt in it?
I have the aeromotive comp kit and ran the vaccum line off the manifold to the regulator so I don't it leaks. But the lines were kinda dirty when we put them on. (You know about these steel braided fuel lines)
Albert
Fuel pressure regulators reduce the fuel pressure when there is vacuum. When the vacuum source is at zero vacuum (atmosphere), then it is operating at full pressure (42 or what ever you set it to). If that vacuum line is plugged, it would definately cause your problem because fuel pressure will be 40-ish at idle, part throttle and WOT. Hook up a fuel pressure guage to the rail and see if your fuel pressure drops when you remove the vacuum line to the regulator. It should also drop when you rev up the motor.
 
Posted by 1SLOWLX (Member # 558) on :
 
Yeah the fuel pressure does drop when we rev the motor up.
Albert
 
Posted by st5150 (Member # 51) on :
 
Sorry, I had a typo... fuel pressure is inversely related to vacuum. Vacuum is inversly related to RPM. So that means that fuel pressure should INCREASE as RPM's go up. What kind/brand of regulator do you have? Do you have an FMU? Something is definately wrong with the regulator or its signal (vacuum source) if fuel pressure drops as RPM's increase.
 
Posted by 1SLOWLX (Member # 558) on :
 
It is only at the start of the rpms the vaccum drop like it is suppose to. When the car rpms start going higher and higher the fuel pressure goes up. IT has the aeromotive comp fuel kit in it.
 
Posted by st5150 (Member # 51) on :
 
yellow94gt on here had his aeromotive fuel pressure regulator's diaphragm rip and allow fuel to be sucked into the intake through the FPR's vacuum line. Have you pulled the vacuum line and smelled it or checked for fuel? I bet your problem is something simple like this.
 
Posted by 89hatchback_lx (Member # 587) on :
 
quote:
Originally posted by st5150:
Yeah, it will make more power (and be louder) with no cats.... but thats not your problem... your problem is that its running extra rich when it warms up... causing you to lose power and over work your cats. Do you have a custom chip for your setep? If not, your combo is begging for one.
could that be my problem? Im having trouble with somthing similler to what *1slowlx* is having. My car runs like crap from 1,000rpm-3,000rpm and theres also alot of poping noise coming fron the motor like back fire. after 3,000rpm the car revs fine all the way up to 5,000 but dosent feel like it has any power to it.
Also my cats glow also. along with the x part of the x pipe. could this be tha same thing??
 
Posted by 99gt-UJSTLST (Member # 584) on :
 
quote:
Originally posted by 89hatchback_lx:
quote:
Originally posted by st5150:
Yeah, it will make more power (and be louder) with no cats.... but thats not your problem... your problem is that its running extra rich when it warms up... causing you to lose power and over work your cats. Do you have a custom chip for your setep? If not, your combo is begging for one.
could that be my problem? Im having trouble with somthing similler to what *1slowlx* is having. My car runs like crap from 1,000rpm-3,000rpm and theres also alot of poping noise coming fron the motor like back fire. after 3,000rpm the car revs fine all the way up to 5,000 but dosent feel like it has any power to it.
Also my cats glow also. along with the x part of the x pipe. could this be tha same thing??
NO BRO I TOLD YOUR ASS YOU NEED TO GET IT TUNED TO MAKE YOUR PROBLEMS GO AWAY
 
Posted by 1SLOWLX (Member # 558) on :
 
Alright I changed my plugs and fired the car back up. I found a bad ground where the computer is grounded and fixed that also. The problem with the glowing cat was gone all day until I got some gas. I filled the gas tank all the way up to the top. The car has aeromotives comp fuel system kit in it. Do you think by chance it could not be returning enough fuel because of the tank being full?
Any help will be great. Tomorrow I will take some fuel out of the tank and run the car again
Albert
 




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