running lean

[jhysock]

89 gt running lean can anyone tell me what the fuel pressure should be or any other ideas of what might be causing this thanks :

 

[HISSIN50]

How do you know it's running lean?

 

[jhysock]

they lost all there color they used to be light tan now there pure white also the car shuts off when coming down to idle from high rpms

 

[HISSIN50]

What codes did the EEC generate? Was one an oxygen sensor code?

 

[jhysock]

15 and 67 failure in eca and improper signal fron nds

 

[HISSIN50]

Do you have a chip or something else plugged into the J3 port?

When pulling codes, be sure the car is in neutral (or Park if an auto) and that the HVAC control is turned to off.

 

[jhysock]

theres a hypertech streetrunner chip in it. a hypertech tech told me that can be causing the 15 code due to the mods done to the engine the chip is for stock only hopefuly that fixes it

 

[HISSIN50]

Having a chip or interface plugged into the EEC can cause code 15, regardless of the tune or mods to the car.

 

[jhysock]

i've unplugged the chip no code 15 still have 67. plugs are still white and now car is shutting off more when coming to idle also i cant pull any koer codes starting to lose my mind

 

[HISSIN50]

Some cars will not spit KOER codes if you have a code 67.

 

[jhysock]

i read somewhere i can bypass the nds by jumping the wire to a ground i might try that tomorrow and see i still don't see why this is making the car run lean and stall at idle but maybe it will let me pull koer codes hopefully
i replaced the computer today and i'm still gettin the 67 code so something has to be wrong with it i'm about to lose my mind i want to pound on this car some more b4 winter its just to much fun

 

[jrichker]

Code 67 - clutch not depressed (5 speed) or car not in neutral or park (auto) or A/C in On position when codes
where dumped. Possible neutral safety switch or wiring problem. This code may prevent you from running the Key On
Engine On tests. You can generally ignore this code, since it has no effect on engine performance.

The computer wants to make sure the A/C is off due to the added load on the engine for the engine running tests. It also checks to see that the transmission is in Neutral or the clutch depressed (T5, T56, Tremec 3550 & TKO). This prevents the diagnostics from being run when the car is driven. Key On Engine Running test mode takes the throttle control away from the driver for several tests. This could prove hazardous if the computer was jumpered into test mode and then driven.

The NSS code 67 can be bypassed for testing. You will need to temporarily ground computer pin 30 to the chassis.
Computer pin 30 uses a Lt blue/yellow wire. Remove the passenger side kick panel and then remove the plastic cover from the computer wiring connector. Use a safety pin to probe the connector from the rear. Jumper the safety pin to the ground near the computer.

 

[jhysock]

bypassed nds and ran koer got codes 41 and 91 02 codes o2's haven't been hooked up since i got the car witj added fuel pressure plugs have a lil color but car is still dieing at idle can the iac be the problem i've pulled it and cleaned it w/no results and i heard of a blockoff plate for this any one try this?

 

[jrichker]

Fix the O2 sensor problems and a lot odf your troubles will go away, including the idle problems.

See the "Surging Idle Checklist for help with all your idle/stall problems. Everything you need to find and fix idle problems is in there.

The first two posts contain all the updates to the fixes. At last count there were 24 possible causes and fixes for surging idle/stall problems. I continue to update it as more people post fixes or ask questions.

 

[87AODGT]

why would you be running with the o2s unplugged? there's pretty much no reason to ever leave them unhooked

 

[jhysock]

they havent been hooked up since i bought the car and can't find where to plug the o2 in there is only one in the h pipe shouldn't there be 2 my first stang and don't know too much about fi

 

[HISSIN50]

There should be one O2 sensor per side.

 

[jhysock]

well ther ain't none there is one o2 in the driver side of the h pipe the other side is plugged and i don't see where i can even plug the one o2 in??

 

[HISSIN50]

Can you remove the plug?
Otherwise, you'll want to get an O2 bung and have it installed.

 

[jhysock]

the plug can be removed the bungs already welded to the h pipe the problem lies after that there is no wiring to connect the o2 to the car apparently thats missing or has been removed do ya really think not having o2 sensors can cause the car to run a lil lean after so long i don't want to burn up the motor