[v8pwrdbird]

hey guys, i am a first time poster. i am new to this forum but not forums in general. anyway, i have a 95 tbird 4.6l that was given to me because the owner ran it through water and could not ever get it restarted. since getting this car, it is now running. the ignition control module had some corrosion and was getting bad connection. so now the car starts and runs okay, but appears to have a poor idle that sounds like a misfire and hesitation. i have replaced all the spark plugs and changed out the oil, filter etc... to help with any possible water problems. this car only has 77000 miles on it and i am a firm believer that this car will breathe life once again. i was checking the plug wires at teh coil packs and on the number 2 cyclinder when removed it made no change to the way the car was running but did however arc to ground. is that a problem and if so where do i go from there. thanks for any help you guys may have.

 

[Greybird94]

Change the wires

 

[Rolling-Thunder]

How does it run when you put your foot on the gas?

Idle only problems are usually caused by a dirty or defective IAC valve.

A dirty or defective MAF sensor can also cause misfires.

Is the check engine light on?

 

[v8pwrdbird]

no the check engine light is not on. it will come on from time to time. the code it pulls is system to lean on bank 1. wires have been replaced, maf has been replaced. i believe teh IAC is okay. it will stumble for a sec then appear to clear it self up. put it does miss throughout the rpm range.

 

[Rolling-Thunder]

Check the condition of the front two O2 sensor connectors, since you said that the car was run thru water. They good have gotten corroded due to this.

Here's the info. from the Ford Srvice CD on troubleshooting a "lean" code:


2S(S) NOT SWITCHING. DTCS P1130 AND P1150: HO2S NOT SWITCHING, FUEL SYSTEM AT THE ADAPTIVE LIMITS (RICH OR LEAN) P0172, P0174, P0171 AND P0175: FUEL SYSTEM AT ADAPTIVE LIMITS

NOTE:
Before servicing DTCs P0171, P0172, P0174 and P0175, verify with the customer that before the "Check Engine Light" came on, the vehicle did not run out of fuel.

Diagnostic Trouble Codes (DTCs) P1131 and P1151 indicate the system is correcting rich for an overly lean condition. The HO2S voltage is less than 0.45 volt.

DTCs P1132 and P1152 indicate the system is correcting lean for an overly rich condition. The HO2S voltage is greater than 0.45 volt.

DTCs P1130 and P1150 indicate the fuel control system has reached its maximum compensation for a lean or rich condition and HO2S is not switching.

DTC P0171, left bank, and DTC P0174, right bank, indicate the fuel/air ratio is too lean. The system is at the rich limit.

DTC P0172, left bank, and DTC P0175, right bank, indicate the fuel/air ratio is too rich. The system is at the lean limit.

DTC/HO2S Reference List

-- HO2S-11 = DTCs P1130, P1131, P1132, P0171 and P0172

-- HO2S-21 = DTCs P1150, P1151, P1152, P0174 and P0175

Possible causes:

Fuel System

-- Excessive fuel pressure.

-- Leaking fuel injector(s).

-- Leaking fuel pressure regulator.

-- Low fuel pressure.

-- Plugged injector(s).

-- Damaged/disconnected HO2S circuit.

Induction System

-- Air leaks after MAF.

-- Vacuum leaks.

-- Restricted air inlet.

-- PCV system.

Base Engine

-- Oil overfill.

-- Cam timing.

-- Compression.

Ignition

-- Coil and secondary side of ignition system.

l Check air intake for leaks, obstructions, and damage.

l Check air filter, air filter housing for blockage.

l Check positive crankcase ventilation system integrity.

l Check engine vacuum integrity.

l Are there any obvious concerns?

Yes
REPAIR any of the problems found in the visual inspection. RERUN «Quick Test».

No
GO to «H41».

 

[tlpru]

idle air control...

if it runs fine....except at idle....i would try that!

if you like shot gunning parts....

 

[pnyklr]

I had a misfire on my 94 4.6 the ECU was bad

 

[v8pwrdbird]

i dont think it is the IAC because it misses as i rev up the engine. last night i unplugged some of the injectors while it was running and two of the injectors while unplugged did not seem to alter the way the motor was running, does that mean my ECU could be bad. the interior did get wet as well. not sure if the ECU did or not.

 

[v8pwrdbird]

i have verified that cylinder number two injector is not getting the signal it needs. i hooked up a 194 light bulb and got no light whatsoever. it blinked just like a noid light would on the other 3 cylinders of that bank. any suggestions as to what would cause the no light on number 2

 

[pnyklr]

advance auto parts sells the ecu's

 

[v8pwrdbird]

does that mean that it is def. the ECU. how can i check to verify ecu is bad. i will probably go to the junk yard and grab one. they have dozens to chose from. probably the easiest way i guess.

 

[pnyklr]

just check the code on it make sure its the same I think theres a post about codes

 

[v8pwrdbird]

well the problem is that it does not always throw a code. but when i do get a code, it gives me "system too lean bank 1". not real sure if that is the reason for the code or not.

 

[cjchevez]

Clean your MAF !

 

[v8pwrdbird]

replaced it and cleaned it as well

 

[v8pwrdbird]

it is only happening on one cyclinder
all the others are fine.
when i take the injector of while car is running, it does not affect how the motor runs so i know it that cyclinder just not sure how to fix it at this point

 

[Rolling-Thunder]

I just scanned thru the Ford CD again for your issue.

The diagnostic subroutine H41 mentioned above will eventaully lead you to check the PCM (ECU) for faults. A test is described - but it sounds like something that has to be done with a Ford diagnostic tool.

So to answer your question, yes, it could be your car's computer at fault.

EDIT:

subroutine H49 CHECK INJECTOR DRIVER SIGNAL

Requires standard 12 volt test lamp.

l Key off.

l Breakout box installed.

l Connect PCM to breakout box.

l Connect test lamp between Test Pin 71 or 97 and each injector Test Pin (refer to chart in «H46»).

l Crank or start engine.

NOTE:
Properly operating system will show a dim glow at idle on the test lamp.

l Does test lamp have a dim glow while cranking or running engine?

Yes
REMOVE breakout box. RECONNECT PCM. GO to «H50».

No
No light/Continuous bright light. REPLACE PCM. REMOVE breakout box. RERUN «Quick Test».

 

[IcemanV8]

I'm just curious... can you hear your valves chattering?

 

[v8pwrdbird]

I'm just curious... can you hear your valves chattering?

i dont think so, i will say that do hear a whistle as soon as i turn the car off. not sure if that means there is a leak or this car just does that. i sprayed with some carb cleaner but got no increase in motor rpm because of it so i stopped looking. but valves chattering i am not real positive. why do you ask

 

[FordMan77]

I'm just curious... can you hear your valves chattering?

Are you thinking that he may have a bent valve, thus its not sealing properly and causing the miss?

Jay