heater core and car running rich

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heater core and car running rich

October 30, 2014, 10:18:41 AM

So earlier this week I kept seeing a puddle under my car. I tracked it down to the drain for the AC, ya know the little black rubber hose that sticks out from the firewall? Anyways, I could see coolant dripping from that AC drain, and then it falls on the exhaust and burns off. Does this mean my heater core is leaking?

And secondly, my file mileage has pretty much gone to shiznit. like in town i get 8-9mpg. And also the cars exhaust is really smelly. So i thought i had burned a valve or 2. Did a compression test, all the cylinders registered 110-115psi. And also, this morning when I got on the gas, I could see black smoke coming out the exhaust. So the cars running rich, but I dont really know why. My first instinct is to check O2 sensors, but what else would cause an EFI car to run rich?

Any info appreciated

-Kyle

heater core and car running rich

Reply #1 – October 30, 2014, 12:19:22 PM

Yes, its the heater core. This is the only thing inside the HVAC box that can leak coolant. Do a couple of searches and the how to's on replacement will come up.

Run the codes, run the codes, run the codes. Without running the codes its just guessing so after you run the codes post up what you get.

Darren

heater core and car running rich

Reply #2 – October 30, 2014, 01:41:44 PM

But it doesnt throw a CEL, so would it still throw a code?. do these cars not have a CEL?

heater core and car running rich

Reply #3 – October 30, 2014, 02:38:46 PM

I've seen cars that did not throw a CEL and have codes. Just scan it and see what happens as it rules out a lot of speculation.

Darren

heater core and car running rich

Reply #4 – October 30, 2014, 02:47:27 PM

Quote from: kylesburrell;439946

But it doesnt throw a CEL, so would it still throw a code?. do these cars not have a CEL?

Yep. Mine throws a code 44 and 94 KOER (Thermactor system is gone) and has no check engine light on.

heater core and car running rich

Reply #5 – October 30, 2014, 04:06:28 PM

And actually, when I run the car hard, the car starts to steam from the AC vents. This is just further proof that I believe that the heater core is leaking.

heater core and car running rich

Reply #6 – October 30, 2014, 07:27:15 PM

There should be no doubt in your mind that your heater core is toast. I would bypass it now so it does not get worse and make a huge mess in your interior.

Darren

heater core and car running rich

Reply #7 – October 30, 2014, 07:35:51 PM

IIRC, the fuel pressure regulator can go bad and cause that mixture problem. Just a rusted-memory guess...

heater core and car running rich

Reply #8 – October 30, 2014, 07:48:30 PM

Vac line on map sensor.

Located on firewall by brake booster behind intake.

Your motor mounts are probably also bad if this hose is shot. Also the vacuum distribution blocks also like to go bad and can do the same thing. Any vac leak makes a speed density car run super rich.

heater core and car running rich

Reply #9 – October 30, 2014, 09:22:05 PM

So I pulled codes. got a code 67 in the "current codes" and a code 34 in the stored "CM". these are from a KOEO test. and also, my EGR vac. source has been plugged, so egr will never open

heater core and car running rich

Reply #10 – October 30, 2014, 09:30:38 PM

Quote from: thunderjet302;439950

Yep. Mine throws a code 44 and 94 KOER (Thermactor system is gone) and has no check engine light on.

Only CERTAIN codes will throw out CEL's on these cars
CIRCUIT CODES

ACT    54, 64
ECT      51, 61
BP/MAP 22
MAF      26, 56, 66
TPS      23, 53, 63
EVP      31, 32, 34, 35
HEGO      41, 91, 42, 92

Code 67 Troubleshooting: http://sbftech.com/index.php/topic,29824.0.html

heater core and car running rich

Reply #11 – October 31, 2014, 12:55:45 AM

If your lucky enough to have a engine light hooked up...

heater core and car running rich

Reply #12 – October 31, 2014, 01:27:05 AM

And so I looked up code 67-which is a park/nuetral safety switch malfunction. not really surprised about that one. cuz lots of times when I have the car parked, I can hear a buzzing from under the car, put it in neutral....buzzing stops. So i figured something there.

And code 34-is egr stuff, but like I said the egr system has its vac. source plugged. So not surprised that its "malfunctioning"

And a vacuum leak wouldnt throw a code? but will make the car run rich as hell?

heater core and car running rich

Reply #13 – October 31, 2014, 08:58:46 AM

For your code 67 issue read HERE

The 34 is exactly what you stated. The ECM will shut off functionality of the EGR and basically work around it.

Generally a vacuum leak will cause a rough idle or popping. Have you hooked up a vacuum gauge to it at all?

heater core and car running rich

Reply #14 – October 31, 2014, 09:56:47 AM

I did, hooked up a vacuum gauge so the cruise control port on the "vacuum hub". It pulled a pretty constant 30psi....or 20psi. when we disconnected the guage it read 10psi of vacuum, so i think it read high. But it was a constant vacuum, so i dont think the engine is misfiring