91 camaro surging

[CRUZIN91]

Hello, I'm new here but anyhow have several projects but my 91 camaro RS is surging at idle and bogs down when trying to drive. I have changed out the fuel filter, cps- thottle senser, coolant senser- because my fan also wont come on unless my A/C is on, and cleaned my throttle body. This has a 305 tbi.
How can I check the fuel pressure on this tbi?

Any help appreciated...

[Genopsyde]

the problem with your fan not coming on is the switch that's in the side of the engine block underneath the head on the right (passenger) side. as for your "surging" is the service engine soon light on? If not you might have a mis-fire.

[CRUZIN91]

Originally Posted by Genopsyde

the problem with your fan not coming on is the switch that's in the side of the engine block underneath the head on the right (passenger) side. as for your "surging" is the service engine soon light on? If not you might have a mis-fire.

Thanks for the speedy reply, the only thing I've seen on the passenger side is the knock senser at least thats what I read it was,., I ran the code and get a code 44 - lean exhuast . I've also have changed out the o2 sensor with no change.

Thats a cool camaro u got.

[Genopsyde]

the knock sensor is on the front of the block, this sensor is on the side. Disconnect your negative battery cable for 10 minutes to clear the codes. when you re-connect it, see if it throw the code again. If not, start troubleshooting your ignition components.

[ct91rs]

both sensors are on the passenger side, but the cooling fan switch is closer to the back of the block (between the 6th and 8th cylinders) and a bit higher than the knock sensor.

[Genopsyde]

yea, what he said...

[CRUZIN91]

Originally Posted by Genopsyde

yea, what he said...

Ok thanks, I'll look for the sensor again next time I have it up on the stands. I started putting on some new plugs and wires, and also have an Accel cap and rotor to put on.
I've unhook the battery before but the code comes back.

[Genopsyde]

From Haynes Manual...

Code 44: Lean exhaust

Lean condition caused by malfunctioning carburetor/fuel injector, vacuum leak, low fuel pressure, etc.; poor electrical connection, open or short in circuit, defective MAP sensor; defective oxygen sensor, defective ECM.

[89IROC&RS]

be careful if you go to replacing that fan switch, it is directly linked into a coolant passage, so when it comes out coolant is going to start gushing out, i know, i took a shower in coolant when i did it. so if you dont drain the coolant first, make sure its not hot when you do it.


as far as the surging, its definatly related to the lean code, which may be clogged fuel injectors, i would get a can of BG 44k, or other fuel system cleaner, and run it through the tank and see if it helps any. to check the fuel pressure, youll need a fuel pressure guage, and fitting. find the black cap on the fuel rails, and unscrew it there should be a valve underneith that your fuel pressure guage should screw onto. then turn on the engine and read the fuel pressure, should be around 40-45 psi with the engine running.

[89IROC&RS]

also, im slightly leaning towards a faulty MAP sensor on this from prior experience with a similar problem. but dont put any money on that, its just a feeling.

[CRUZIN91]

Originally Posted by 89IROC&RS

also, im slightly leaning towards a faulty MAP sensor on this from prior experience with a similar problem. but dont put any money on that, its just a feeling.

Thanks for the input 89IROC&RS, would'nt I get a code for the map sensor though? As far as the fuel pressure I have a throttle body so I dont see any fitting, I was on thirdgen.org and they have a link to a tbi specialist that has some good info on tbi's, www.cfm-tech.com. They show how to check for fuel pressure on the tbi's.
Thanks for the shower tip, coolant sensor.

I may go ahead and replace my fuel reg. , but I'm going to check the pressure first.

Thanks

[Genopsyde]

Originally Posted by Genopsyde

From Haynes Manual...

Code 44: Lean exhaust

Lean condition caused by malfunctioning carburetor/fuel injector, vacuum leak, low fuel pressure, etc.; poor electrical connection, open or short in circuit, defective MAP sensor; defective oxygen sensor, defective ECM.

werd

[89IROC&RS]

maybe thats where i read it............




but no i really did have a similar problem that was a map sensor, so just an idea.

[skyjack]

my brother had same problem ,found to have a bad fuel pump

[supercarvideos]

i would get a can of BG 44k
======================================WJFK....... 106.7.......... huh?