install headers/ problems with idle-power

[punkmilhouse]

Hi,

I need help i installed some headers today and now i have some issues :

- the car starts weak/ and it turns off after a while

- when i drove the car, it requires for me to really step on the gas for it to rev up .

- i have some vacuum hoses that i have no idea where they go, but they seem to not suck air.

- I noticed that i could not hear air being sucked in by the intake. which i usually do.

- lastly there are two connectors coming from the main harness, that go into the front of the engine. one is connected to a temp sensor i think , but the other one i have no clue.

Thanks.

[BRAAP]

Is this is a 280-Z with EFI?

You do have a service manual, even if just a Haynes manual right?

 

Assuming this is a stock 280-Z, my knee initial reaction would be to very the water temp sensor is not connected. With it disconnected, the engine will usually start, run rough, and as the engine warms up, run worse and worse with lots of black smoke out the tail pipe.

If this is indeed your problem, there are what look to be two sensors for the EFI that are in the thermostat housing. One is larger and bulkier than than the other, but the sqaurish shaped electrical connectors look the same, just like the Injectors actually.

The smaller one is the EFI temp sensor and it MUST be connected. The larger one is the Thermo-Time switch and can be left unplugged, it has NO affect on the engine running performance whatsoever!

There are 2 plugs that up by the thermostat that plug into these sensors, sometimes they get crossed up. Both connectors run up the harness to near the throttle linkage where they both disconnect from the EFI harness with bullet plugs, 4 wires, one pari for each sensor, (one is actually the Thermo-Time switch, not a sensor). One pair of those wires will have red tape wrapped around it on both sides of the Bullet connectors, to help keep from crossing these sensors. The pair with the read tape is the pair that for the water temp sensor. Be sure those are connected a the bullet plugs and that pair is connected to the water temp sensor, do NOT worry about the pair with the red tape or the larger bulkier thing in the thermostat housing.

 

Another thing that can get crossed up is inadvertently sonneting the Air Flow Regulator to the cold stat injector which opened it and floods the engine as Air Flow Regulator is hot 12V power when the engine is running. To eliminate that, just unplug the cold start injector, just in case. Don't worry about the cold start injector, it has NO affect whatsoever on the engines running. In fact, that larger bulkier thing in the thermostat housing is what controls the cold start injector and is only supposed to come on for brief second while cranking the engine in very VERY cold conditions. I personally eliminate that cold start circuit all together as it is really doesn't help and can be source a frustration for some.

 

Hope that helps.

[punkmilhouse]

-Hi

Thank you for the response. Its a 78 280z. I do have an online manual for the car, I recently got the car so I am not familiar with it.

I am sure i have the temp sensor connected, because i tried connecting both connectors into the sensor and one of them started the car with the problems i am having, and the other one as soon as i turned the car on, the RPMS would fly up. So i left the one that kept the RPMS "normal".

I am going to disconnect the cold start to see if i messed up with the air regulator, but as i am looking at the manual i see the pictures of these things, but i have no clue where they are in the engine bay. I am going to try to take a picture of the engine, see if i can get some help, where stuff goes.

Thanks again.

[punkmilhouse]

-Hi

Thank you for the response. Its a 78 280z. I do have an online manual for the car, I recently got the car so I am not familiar with it.

I am sure i have the temp sensor connected, because i tried connecting both connectors into the sensor and one of them started the car with the problems i am having, and the other one as soon as i turned the car on, the RPMS would fly up. So i left the one that kept the RPMS "normal".

I am going to disconnect the cold start to see if i messed up with the air regulator, but as i am looking at the manual i see the pictures of these things, but i have no clue where they are in the engine bay. I am going to try to take a picture of the engine, see if i can get some help, where stuff goes.

Thanks again.

[punkmilhouse]

-Hi

Thank you for the response. Its a 78 280z. I do have an online manual for the car, I recently got the car so I am not familiar with it.

I am sure i have the temp sensor connected, because i tried connecting both connectors into the sensor and one of them started the car with the problems i am having, and the other one as soon as i turned the car on, the RPMS would fly up. So i left the one that kept the RPMS "normal".

I am going to disconnect the cold start to see if i messed up with the air regulator, but as i am looking at the manual i see the pictures of these things, but i have no clue where they are in the engine bay. I am going to try to take a picture of the engine, see if i can get some help, where stuff goes.

Thanks again.

[punkmilhouse]

the problem was a leak somewhere in the intake manifold and exhaust manifold. thanks for the help. i just have some vacuum qustions... there is a vacuum line coming under the intake hose, where does that one go?

Edited July 13, 2010 by punkmilhouse