93 caprice has hunting idle

[HUSTLEMANLV]

93 caprice lo5 tbi
new fuel filter
new air filter
new injectors
new IAC motar
o2 sensor
map sensor chks good
throttle position sensor chks good
I'm geeting a code 15 23 34 and 44
once car is hot it stops hunting at idle
if cold it goes from 500 rpm to 1500rpm
any thing will help
[email protected]

[CD Smalley]

Do a search here for How Do I read my computer codes. There's a list of what the codes are that should be fairly accurate for you.

Start with the first one. It's your Coolant Temp Sensor. Make sure all of your sensor connectors are plugged in good.

[CapriceCop]

HustlemanLV,

I recently went through a similar problem and I am not sure how similar your car is to my '90 Caprice TBI. I found the Air Charge Temperature Sensor to be the issue. Mine is located inside the air cleaner housing closer to the center than the air cleaner. Mine would act up when the moisture was high and since replacing I have driven in the rain and high humidity with out the problem. It might be shorting until it is hot. Just a thought.

Keith

[HUSTLEMANLV]

i put a new coolant sensor / inlet sensor / problem remains any help?

[CD Smalley]

Did you reset the computer and are you still getting codes?

If no codes I'd look for a vacuum leak somewhere. Probably the TBI to intake manifold gasket.

[HUSTLEMANLV]

i replaced the tbi to manifold gasket but i will clear the computer and see what happens

[HUSTLEMANLV]

I check all connections and now have a code 34 and 44. stall from a cold stop the engine will stumble on accelaration. also the car will some times surge when speeding up

[CD Smalley]

34 = Map Sensor
44 = Lean Exhaust - O2 sensor.

Start by running the vacuum line that runs to the MAP sensor. Make sure it doesn't have any cracks and is attached firmly at both the sensor and the TBI.

You can check the voltage of the O2 sensor with a DVOM and see what you are seeing there. They are cheap enough I would jst replace it.

[HUSTLEMANLV]

Re: 93 caprice has hunting idle
replaced map
checked o2 connection
still have code 44
car surges when warm
idles from 500 to 1500 rpm
sprayed carb cleaner all over the tbi/intake area no changes in idle
any ideas
350 5.7 tbi

[silicon212]

Did you check the IAC (idle air control) solenoid or system?

[HUSTLEMANLV]

iac motor has been replaced
intake manifold bolts are tight
checked for vac leaks - none found
new map sensor installed
if car is ran cold without the o2 sensor hooked up there is no change
car runs in cloosed loop with o2 once rngine warms up
intake temp sensor is new
coolant sensor is new

[CapriceCop]

I posted a response earlier to your problem that may have been overlooked. Have you tested the air charge temperature sensor? I went through almost every sensor and gasket trying to stop my erratic idling. Then I found the little guy inside the air cleaner housing and replaced it with great success. Since then, the idling has become better and I noticed a better gas mileage(still waiting to fill up again to calculate). For $15, I was happy to finally figure this out.

Keith

[HUSTLEMANLV]

I had a spare IAC sensor and swaped it to no change I'll try a new one