Having problems with my 86 monte (4.3L v6, fuel injected)

[xminnis]

every day when i start it up it idles horrible it revs up to about 1 on the tach then sputters to almost stalling, revs back up, sputters, revs up, sputters, over and over and it will die about 5 or 6 times and need to be started again. Once i let it run like this for a bout 10 minutes finally the idle will even out and sound decent (not good) but decent... I can not even attempt to drive it until the idle evens out or it will have a horrible hesitation to the point of almost stalling when i try to punch the gas. But once the engine is warmed up it drives decent but the check engine light will pop on in about 5 minutes, and sometimes it will have hesitation taking off from a stop light but not always.

I tried changing fuel filter and running fuel system cleaner through it every time i filled up for the last 3 or 4 tanks but it is still doing the same thing with no improvement. Does anyone have any ideas?

 

[TURNA]

maybe a bad injector. do u have a noid light?

they are cheap and sold at advance pep boys etc

also do the throtle bodies have an IAC?

 

[outsider_27]

NOt sure but could be a clogged catalytic convertor? Should be able to take it to a parts store and have the code read to find out what the code is.

 

[xminnis]

no i dont have a noid light i might go get one. and i am not sure if the throttle body has iac how can i check? Also i tried taking it in to have the code read but they cant check the engine lights for anything older than 96

 

[TURNA]

all u need is a paper clip to read those cars

4.3L VIN Z TBI

Turn ignition switch to OFF position
Locate Data Link Connector
Jump the A&B terminals with a paper clip
Turn Ignition switch to ON position.
Count the flashes on the "CHECK ENGINE" or "SERVICE ENGINE" light.
FLASH, pause, FLASH, FLASH = code 12

A - Ground
B - Test Terminal


13 Oxygen sensor voltage stays between 0.35 and 0.55 volts for 60 seconds. Engine was at normal operating temperature and had been running for at least 2 minutes after start with a throttle angle above 5%.
14 Coolant temperature sensor signal indicates a temperature of over 275� F for 2 seconds.
15 Coolant temperature sensor signal indicates a temperature colder than -27� F for 30 seconds after the, engine has been running for at least 30 seconds.
21 TPS voltage was above 2.5 volts for 8 seconds when the MAP sensor signal showed manifold vacuum to be 15 pounds or more.
22 TPS voltage was under 0.2 volts for when the engine was running.
23 Inlet air temperature sensor signal showed an air temperature below -22� F after the engine has been running for 5 minutes.
24 When engine speed was between 1200 and 4400 RPM and throttle position angle was less than 3%, the MAP signal showed low voltage (high manifold vacuum) for at least 5 seconds.
25 Inlet air temperature sensor signal showed an air temperature over 302� F after the engine has been running for 5 minutes.
32 EGR open command did not change the fuel mixture when the command was given during off idle operation. EGR opening should cause the mixture to be slightly richer because of the low oxygen content of exhaust gas.
33 MAP sensor signal voltage was too high (low vacuum) for 5 seconds when throttle opening was under 4%.
34 MAP sensor signal voltage was too low (high vacuum) when engine speed was over 1200 RPM, or the throttle angle was above 21% when engine speed was over 1200 RPM.
42 The EST signal did not change when the ECM applied bypass voltage to the ignition module.
43 The ECM did not detect a knock signal during near wide open throttle operation with coolant temperature above 194� F or the knock signal was present for 5 seconds or more during normal engine operation.
44 Oxygen sensor voltage was under 0.25 volts for 50 seconds of closed loop operation.
45 Oxygen sensor voltage was over 0.7 volts for 30 seconds after engine had been running for 1 minute with a throttle angle between 2% and 20%.
51 PROM error.
52 CALPAK error.
54 Fuel pump voltage was not present at fuel pump sense line for 2 seconds after the ECM has sent the fuel pump on command.
55 ECM error. Replace ECM.

 

[megaladon6]

vacuum leak. it's pulling too much air to correct for when cold, when it's warm it can adjust. or the seal that's leaking may even swell when it heats up, sealing things off. use some brake cleaner and spray the gaskets and vac lins, etc. if you hear the engine pitch change, you've found the leak.
it could also be a bad IAC, but i doubt it. they usually stay bad, independent of temp.
a bad ECT is also possible.