Rmagic13b

im not sure but i recently put a downpipe on and when warming up it starts glowing and getting pretty red. Exhaust tempreature seems too hot but im not sure if that is because there's no cats or is there a bigger problem?

RX7LINK

iTrader: (3)

its strange that the downpipe turns red during warm up. but usually a exhaust temp too high = engine running lean on air/fuel ratio. u might have dirty injector or clogged fuel filter. unless u bought a used ecu that the tuning was set for another car that has different setup.

No-Pistons-TT

are u sure its not you main cat thats glowing or your turbos???

Rmagic13b

it doesnt have any cats

nashman69g

iTrader: (3)

he doesn't have cats...list your mods that my help to see your problem.

kraked

how long before it starts glowing?

lilfreddie

We Just Fixed A Customers Car. His Manifold Was Glowing On The Front Rotor Exhaust Outlet. I Sent The Injectors To Rc Engineering And One Of The Secondary's Was Dripping! Problem Solved. If I Can Help Give Me A Call

RX-7projectRX7

A lean condition won't cause this, a RICH condition will. If you're running too rich, fuel will end up burning up in the downpipe, causing it to glow red. If your timing is too retarded, the same thing will happen. Stock fuel and timing maps are set to exactly these condtions to heat both the precat and main cat.

Ibumar

I also get this. It gets more pronounced the colder the wether is. Happened on stock ECU and now on the Pettit one. Doesn't happen at all during the summer months.

spurvo

Accelerated Warm Up has a fuel dump cycle to heat the pre-cats (which are of course gone by now, but the CPU doesn't know that ). This takes place ~30 seconds after startup, and contributes to the rough idle many experience upon startup. As the car warms up, the fuel is leaned out, idle quality smooths, and downpipe stops glowing. Scared hell out of me first few times I saw it. Happens less in warm temps, hard to determine if this is the water temp sensor, outside air temp sensor, fuel temp sensor, or intake air temp sensor controlling this... I vote outside air temp, located in the ECU itself. Hmm..

Indian

iTrader: (1)

Bro, you have some **** to sort out when it comes to a/f. Even carb guys know that red hot mani is lean. WTF??!?!?!

RE-Amemiya7

More fuel actually actually lowers the engine temp,this is why top fuel dragster run so cool. The leaner the car get the hotter it gets. The DP, I dont believe that it shold be glowing right after start up, mine glows quite red after some laps on the track, or some spearited driving around town. If you had cats on the car i would say they are mostlikely becoming cloged, but without the cats I would be looking at the ingectors first.

Rmagic13b

I have 3 inch exhaust and a greddy bov. Im not driving it till i have a pfc but i just start it up once in a while so that it just doesnt sit there

Cgotto6

iTrader: (8)

Bro, actually both can cause glowing exhaust parts. I was having a glowing DP/mani problem and it was due to running extremely rich. There was raw fuel getting ignited in the manifold causeing it to glow.

Check all your grounds, and make sure your injectors are working properly. Wouldnt hurt to throw a new O2 sensor in there as well. Maybe your air intake temp sensor, and the water temp sensor (the one for the ecu). Those all contribute to the afr's of the engine.

dgeesaman

iTrader: (7)

Exactly - hot exhaust can be from either unburned fuel burning in the exhaust, or hot egts due to near-stoich or lean burn in the combustion chamber. Somewhere in the middle is the rich level that makes for the coolest EGTs.

I was getting a slightly glowing DP during the warmup of my car, and I recently learned that I had a dripping primary. I orginally thought it ran that rich due to the warmup cycle, but I no longer believe that's true.

Dave

RX-7projectRX7

OK, let me explain this so people like you can understand it. A lean condition will cause higher engine water temps (Due to the slower burn times causing the flame front to contact the housings/cylinder walls for a longer period of time). It can also cause higher egt's for the same reasons, but such heat and velocity of gases cannot be generated to cause the downpipe to glow red at IDLE (egt's are only about 700 F at idle). You obviously didn't read what was posted or simply don't have the brain power to understand the symptoms. Given the situation at which problem is occuring, it is much more likely that he has a leaking injector (causing him to run rich... which was dgeesaman's exact problem) , or he could have an ACV switching solenoid problem, causing air to be dumped upstream when it should be diverted to downstream.

I'm only an ASE master tech, maybe I don't know what I'm talking about.

Rmagic13b

Check all your grounds, and make sure your injectors are working properly. Wouldnt hurt to throw a new O2 sensor in there as well. Maybe your air intake temp sensor, and the water temp sensor (the one for the ecu). Those all contribute to the afr's of the engine.[/QUOTE]

could you tell me how i could check my injectors, or send me a link to a thread, i recently put a new o2 sensor in so i doubt its that

Bad_Karma7

If you have a manual, check through section F. I believe the only way they describe testing injectors is to yank out he fuel rail. After shutting off fuel to the rail durring testing, no more than one drop per 5 min IIRC.

mark57

A customer car had this problem. Although the injectors were <2 yrs. old, RC Engineering found the primaries to be dirty and a secondary injector was stuck partially open - it caused raw fuel to mix with the exhaust and ignite in the hot manifold even after the engine was off. The fuel tank was clean and the fuel lines were okay.

Don't pull your injectors until you have new injector seals/gaskets in hand; do not reuse the old seals. Read the FSM, pick up a wrench, and get after things.

dgeesaman

iTrader: (7)

IMO this is not a sufficiently useful test. It did not show the dripping primary (which didn't leak, but did overflow during partial duty cycling). If there is a reason to even suspect your injectors, just send them out for a proper clean&test.

Dave

Rmagic13b

alright..if you guys have any recommendations for any rotary shops in oregon please tell. I know of hayes rotary in washington but if there's one in oregon i would much rather go there.

Rmagic13b

nvm i found a place down in portland thanks for all the help tho

Cgotto6

iTrader: (8)

Haynes was the worst shop in the history of shops. They have been shut down, luckily. Look up Pineapple Racing. Theyre in oregon somewhere.

If you are getting your injectors cleaned, I recommend Witchhunter performance. The dudes great, and he knows what hes doin.

Bad_Karma7

I second that on Witchhunter, Gordon is one hell of a nice guy. He gets his o rings (which are viton) custom made to fit perfectly. Heard a rumor that some companies don't use viton because the alternatives are more cost effective. Give him a call... Witchhunter

Cgotto6

iTrader: (8)

Yep, I just got some injectors from him last week. Installed them and theyre working flawlessly. The seals he gives you with them are awesome. I could tell when sliding them into the rails they were a sure seal. Hes got good turn around on parts too. Only 2-3 days I think.