Engine codes, how to fix

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Engine codes, how to fix

December 30, 2009, 05:37:13 PM

I ran engine codes on the bird tonight, bought a semi cheap scanner and the results are

23: Throttle position sensor signal voltage out of test specifications. I ran three tests and this came up once.

67: Improper signalssent from nuetral driveswitch, nuetral gear switch, nuetral pressureswitch etc..

33: EGR valve position sensors or pressure feedback indicated egr valve is not opening.

I'm not too concerned with 67, I know I can shift the car out of gear without the key being inserted into the ignition. Any ideas on the other two? The car was warm, for about 10 minutes, is it possilbe the EGR didn't warm up? I'm letting it idle now, I'll recheck codes again in a few. Just thought I would post.

Engine codes, how to fix

Reply #1 – December 30, 2009, 05:55:33 PM

Alright I drove it around for a few, after it was running, tested codesagain got 23, 67, 1, 33. I'm not sure why 1 came up, it means all clear. But I'm looking at the codes listed above. Help? Can an EGR be cleaned? Is that the cnoical shaped white thing on the back of where the air intake connects.

Engine codes, how to fix

Reply #2 – December 30, 2009, 06:31:43 PM

dissconnect the battery and hold the brake pedal down for a few seconds to clear the codes, connet the battery and drive it around for a bit and retest.
then post what codes you have after all that.

is it running funny or were you just curious to see what codes come up?

Engine codes, how to fix

Reply #3 – December 30, 2009, 06:43:55 PM

Well randomly the car will rev, either in park or drive, which is kind of dangerous. And the car seems to burn a lot of gas, more than it should. So i thought it might be worth testing before I threw money at it not knowing. I recently just put a new battery in the car, so the codes were cleared when I did that.

Engine codes, how to fix

Reply #4 – December 30, 2009, 08:42:57 PM

what code scanner did you use? i couldnt for the life of me find an odb0 scanner for my car(or a factory one) when i was searching for one.
were the same codes shown during a self diagnostic test with a test light?
when i ran codes on my tbird and got 33(egr) it wasnt from the egr valve, that worked fine, it was because one of the small plastic hoses got knocked off down by the smog pump(while i was changing plugs i think) and the heat riser thing wasnt opening.
corresponding rough running and very lousy gas mileage vanished once it was fixed.
your idle issue may also have something to do with that but it was a while and a few cars ago so my memory isnt all that great. i wouldnt assume the TPS sensor is at fault right away. not that you were or anything...

Engine codes, how to fix

Reply #5 – December 30, 2009, 09:55:57 PM

the 1 is a separator code,, it separates codes that are happening now from codes stored in memeory.

as i said before, i modifed the drawing so i substitute in a 12v buzzer (option 1) to hear the codes so i can focus on listening and writting the numbers.

http://www.therangerstation.com/tech_library/OBD_I.html

enjoy:D

specs say that it takes 40 warm up cycles to clear any long term stored codes. just worry about the codes that show up now.

as for clearing the immediate codes, others have thier way of doing it but i just yank out the jumper wire while the codes are being dumped out and they go away (only on my 20th, not on my 87LS).

Engine codes, how to fix

Reply #6 – December 30, 2009, 10:04:22 PM

quoted from my in work DIY list for the tps test

----------------------

tps test throttle position sensor
1 location-- vertical mounted on pass side of CFI with org/blk/grn wires.
Probe the green wire with positive lead of a meter and ground out
the black lead of your meter.

2 turn ign sw on ,, no start

3 the voltage reading on your meter should be around .5-.9 vdc.

4 operate the throttle linkage very very very slowly and note increase in voltage. Your increase should be smooth with no jumping and it should top out at around 4.6 vdc.

notes..
It is best to use an buttstuffog (needle type) meter when doing this step because it will detect flat or open spots on the variable resiseter (tps) better than the digital types.
you can bench test the tps buy hooking up to the green and black then black to org and measuring resistance and the two readings should match. The green wire is the center tap of the variable resistor. The resistance reading will be proportional to what you see in dc volts.

if you find your low end voltage is at or above one volt,, use a chainsaw file to file out the mounting holes so that you can mount and adjust the tps CCw to achieve the "less than a volt" goal.

when installing the tps,, lay it in place but slightly clockwise,, seat the tps then rotate it ccw to line up the mounting screws. There is a little pin up in the likage that will put your tps in a bind if you dont do this correctly. You cant just lay it on and bolt it down any old way.

Engine codes, how to fix

Reply #7 – December 30, 2009, 10:09:35 PM

quoted from my diy link,, some info about the EGR.

basically a rubber umbrealla moves based on vac pressure. the rubber diaphram moves a pin which is moving a variable resistor. if the diaphram in your egr is blown, it will not move the EVP sensor.

stick a vac line on the egr and suck on the other end of the hose. now let the hose stick to your tongue. if it holds your tongue to the hose for a min or so, its a good EGR and perhaps the evp sensor is worn....your can read below and get the idea.

==================
=============================
EGR/emissions solenoids (codes)
Dual Thermactor Air control Solenoid Valve- both should read 51-108 ohms
EGR Solenoid Vacuum Valve Assembly - both should read 32 to 64 ohms
EGR Valve Position Sensor EVP (OR/W to brn/ltgrn resistance is 5.5k with no vac and 100ohms with vac)(4-6vdc on VREF or/wht)
Electronic Vacuum Regulator EVR 30 to 70 ohms (koeo voltage is about 10.5vdc)

============================\
EGR test and EVP sensor test
apply vac pres to egr vac line fitting.
if it holds the diaphram for a long time,, the diaphram is good
remove carbon buildup on egr base as well as egr base plate assy for 3.8l engines

EVP test (egr sensor)
wire id...
EEC PIN 26 "VREF" orange/white (parallels off to map)
EEC PIN 27 "EVP SIGNAL" brown/light green
EEC PIN 46 "SIG Return" black/white (parallels off to self test conn)

disconnect vac line
disconnect elec conn
hook ohm meter up to the VREF adn EVP Sig contacts
hook up vac guage or apply vac to egr
ohm meter should start out at about 5.5k ohms.
as vac is increased to max, resistance should bottom out to no less than 100ohms.

key on, engine off
cap off vac fitting on evp sensor
measure for 4 to 6 volts dc between VREF and SIGNAL RETURN (ground)
______________________________
ECT sensor test feeds the computer
Resistance test pin to pin of the sensor (this is a variable resister proportional to temperature including outside air temp if the motor is cold)
at 50degF=58K ohms
at 65degF=40K ohms
at 180degF=3.6K ohms
at 220degF=1.8K ohms

next clean the end of the sensor with scotch brite ect and retest
if high temps persist, replace coolant temp sensor and ECT as a matched set.
if that does not work, start looking at your coolant system parts.
----------------------
ACT sensor test ,,,feeds the computer
Resistance test pin to pin of the sensor (this is a variable resister proportional to temperature including outside air temp if the motor is cold)
at 50degF=58K ohms
at 65degF=40K ohms
at 180degF=3.6K ohms
at 220degF=1.8K ohms

Engine codes, how to fix

Reply #8 – December 31, 2009, 01:33:10 AM

MIL indicator light huh.........?

Engine codes, how to fix

Reply #9 – December 31, 2009, 03:15:38 PM

Quote from: shame302;304561

MIL indicator light huh.........?

What?

Engine codes, how to fix

Reply #10 – December 31, 2009, 03:44:48 PM

Quote from: jpc647;304649

What?

he means the "check engine light", malifunction indicator light(MIL) is the proper way to refer to it. atleast i hope thats the right way to...

Engine codes, how to fix

Reply #11 – January 01, 2010, 12:40:48 AM

Quote from: Ductape91;304654

he means the "check engine light", malifunction indicator light(MIL) is the proper way to refer to it. atleast i hope thats the right way to...

Depending on year model, Ford interchangeably used MIL (Malfunction Indicator Light) and CEL (Check Engine Light) terminology for the same purpose. The CEL was not wired out on the 86 and earlier 'Birds, and the only way to check the codes is with an external light or buzzer connected to the STO pin of the DCL, or re-wire STO to one of the unused indicators in the cluster. Gotta remember, OBDI and EFI technology was still evolving, and everyone was still trying to get the engineers to agree on what light should be used for what purpose. If you want 5 ONLY ways to do something, just ask 5 engineers.

Engine codes, how to fix

Reply #12 – January 01, 2010, 05:17:34 AM

Thanks for the clarification. I disconnected the battery yesterday afternoonand hit the brakes like told. I left it disconnected just to be sure that it would clear them. I'll test it again in a few hours when it is light out.

Engine codes, how to fix

Reply #13 – January 01, 2010, 05:49:28 PM

Alright, I left the battery disconnected for 18 hours and just ran codes again/. The EGRcode is still stored, but the code 23 for the tps went away. I'm going to check the tps using what was listed above, and check it out. It seems like that could cause my engine rpm spikes thought.

Engine codes, how to fix

Reply #14 – January 02, 2010, 05:59:29 AM

The voltage on the tps sensor should remain steady with no spikes or drops in voltage. If it does that at all, it is bad. You also need to make sure the car is warm, and when you set your idle speed, unhook your i a c and turn the throttle screw till it idle's where you want it. When your i a c is plugged in, it should be fine to drive. I didn't have to wait for the car to learn to idle.