5.0 running terrible June 04, 2008, 01:13:55 PM i recently put an electric fan in my thunderbird and when we wired up the thermostat thing we ran one wire to a red wire on the little relay looking thing mounted by the air box. this wire is only there to send 12v to the relay for the thermostat to sense that the ignition is on. a couple days later, all the power that went through this wire was lost, so i moved the wire for the fan to one of the wires on the alternator and that works fine now. my question is does anybody know what the relay looking thing by the air box is for? could this be the reason it is running like ? Quote Selected
5.0 running terrible Reply #1 – June 04, 2008, 01:53:59 PM That sounds like your WOT A/C cut out relay. I do not have a wiring diagram handy to post though. If it is, the Red wire is Voltage Reference from your ECU which would explain why your engine is not running well. The load from the fan relay probably overloaded the ECU and fried something.Mine has the following wire colors: Red, Pink/Lt Blue, Pink/Dk Blue, Orange/White and Black/Yellow. Quote Selected
5.0 running terrible Reply #2 – June 04, 2008, 03:08:44 PM Quote from: GreyWolf30;221999That sounds like your WOT A/C cut out relay. I do not have a wiring diagram handy to post though. If it is, the Red wire is Voltage Reference from your ECU which would explain why your engine is not running well. The load from the fan relay probably overloaded the ECU and fried something.Mine has the following wire colors: Red, Pink/Lt Blue, Pink/Dk Blue, Orange/White and Black/Yellow.so do you know how to check where the problem would be? i think that is what it is. is there a fuse or anything i can check? i am hoping that i wont have to get a new ecu but i guess i should have checked what i was doing before i did it Quote Selected
5.0 running terrible Reply #3 – June 04, 2008, 04:26:21 PM i just pulled the fuses to check if any was blown and none were, but after i checked again i noticed that i had power again to the red wire that goes to the relay thing. the car is still running really rough tho. it like... surges while its idling and it kinda sounds lopey i guess and when i hit the gas it revvs up but backfires kind of when its coming back down to idle. also when you rev it to like 2 grand and hold it there it is really rough and it kindof sounds like its missing. i also lost alot of power. does anybody know what this could be? im wondering about the ecu or cam timing or something Quote Selected
5.0 running terrible Reply #4 – June 05, 2008, 01:35:06 AM Is your "Check Engine" warning light turned on?I would check base ignition timing first and adjust if needed. Ensure it is at 10 degrees BTDC (if you usually have it advanced a few degrees, you can set it back later). Next, take it for a drive (if possible); about 6 to 8 or so miles, up to at least 45 to 60 mph for a mile or two if possible, to get it really warmed up and so any continuous error codes can set (if any are present or occur). Next pull the codes in the KOEO (continuous codes will be displayed after the KOEO codes if you are using jumpers and the dash light or a simple tool with a LED light) and KOER ECU tests. Record the results. After you do this, clear the codes in the ECU by disconnecting th negative battery cable for at least 10 minutes, then reconnect and repeat the above. If you post the code results I should be able to assist you in solving the errors. If you get no results at all, along with no "Check Engine" light, when not using a scan tool or volt meter (using jumpers only), check the bulb for the warning indicator to ensure it is not burnt out. If the bulb checks out as ok, the ECU may indeed be fried and stuck in a "limp home" mode. Same thing if you get no results when using a scan tool or volt meter. Sometimes the ECU and/or scan tool are able to "tell" you directly that the ECU is damaged.BEFORE replacing the ECU, I strongly recommend unpluging the harness from the ECU and checking each wire (and sensors) for damage/short/open, repair as needed and retest if wiring repairs were done. If you have damage in the wiring, you could fry a new ECU really quick.Please post your results.Michael Quote Selected
5.0 running terrible Reply #5 – June 05, 2008, 06:44:19 AM thanks for the advice. i will check it but i have already noticed that the check engine light comes on before i start the car and goes off when i do start it so its not on and i know it works so i think its the ecu and i will look more later tonight. thanks Quote Selected
5.0 running terrible Reply #6 – June 05, 2008, 01:07:56 PM good news. lol. i think i fixed the problem. i dont know what it was but i hooked the timing light up to it and the timing was jumping all around so i shut the car off and took the distributor cap off and looked at everything and then put it back together and fired it up, timed it to 10* again and its fine now. all power is back and it runs smooth now so i hope it stays like this now. lol Quote Selected
5.0 running terrible Reply #7 – June 05, 2008, 09:11:44 PM run codes on it and it might give you a good idea what the problem was. Could be a tfi module. Quote Selected
5.0 running terrible Reply #8 – June 11, 2008, 06:00:19 PM well i thought the car was fixed but it recently started running rough again. how could i tell if the tfi module is bad and the check engine light isnt on? i havent messed with many vehicles this old, but i know on the obd cars it wont read any codes unless the check engine light is on. also, what all would i need to replace if the module is bad? Quote Selected
5.0 running terrible Reply #9 – June 13, 2008, 12:45:53 AM I've heard you can get them tested at autozone, but i've never tried. Running codes is stupid easy and you should still get codes even without the check engine light being on. Check out jcassity's thread. It has alot of useful infomation. You need a tfi tool, or a thin walled 5.5 mm socket I think... Get your codes ran at autozone for free, or check out jcassity's thread. Quote Selected
5.0 running terrible Reply #10 – June 13, 2008, 08:01:12 AM Quote from: 88tbird5.0;223100well i thought the car was fixed but it recently started running rough again. how could i tell if the tfi module is bad and the check engine light isnt on? i havent messed with many vehicles this old, but i know on the obd cars it wont read any codes unless the check engine light is on. also, what all would i need to replace if the module is bad?TFI modules are often interminant, only way to tell is sub another(most of us old timers keep a spare or two on hand)...It may have stored a code in memory even with no CEL... Do a KOEO test and see if it comes up with anything... If you get a "11"(pass), just means there are no hard faults, wait for it to give codes in memory... I'm bettin' it has something in memory... Quote Selected
5.0 running terrible Reply #11 – June 13, 2008, 12:54:13 PM i havent had a chance to get it in and get the codes read yet but i did replace the tfi module and the problem didnt go away. it seems like everytime i start the car i time it to between 10 and 13*btdc and it runs fine for a little bit but it still idles funky and sometimes wants to die when its in gear when you dont give it gas. but when i let the car cool down like overnight i start the car up and it runs real bad like when i start it it surges up to like 750 rpm real quick and then back down and dies and it does this until it gets warm. and then it seems like i have to retime it back to somewhere around 10-13*btdc and its usually fine again. also when i first start the car cold it seems like there is a vacuum leak or something under the dash cuz i can hear what sounds like an air leak but this goes away. i checked the vacuum lines under there but they all look fine though. my dad and i think its either a vacuum leak causing it or a stretched timing chain maybe? sorry if this isnt the best explanation and im gonna try to get the codes checked soon but the car wont be going too far soon due to a small hole in the radiator Quote Selected
5.0 running terrible Reply #12 – June 13, 2008, 01:50:21 PM Some of your cold start & idle issues sound like mine, which I am still working out. A badly worn timing chain will cause some of the same issues as well vacuum leaks. A few suggestions:1) Make sure the "spout" connector is disconnected when setting your base timing. This prevents the ECU from advancing the timing. If left connected, you will have the wrong base timing and wil certainly have issues. If the "spout" is not reconnected, the ECU cannot advance the timing, also causing issues. 2) Get those codes! I am almost certain something has set a code. Beware though, the part that set the code may not be the actual cause. It may be showing you that something on that circuit or the conditions it is monitoring is wrong. (i.e.: O2 sensor shows always lean: could be O2 sensor, a problem with the wiring, a faulty injector, air entering the exhaust through a leak/crack or something else).3) Sometimes a stuck EGR Valve or EGR Valve solenoid can cause issues if the valve is open at idle. Acts like a major vacuum leak. Pull the vacuum line off the EGR Valve and see what happens. The ECU will normally give a code if there is an issue here, but not always.4) Hook up a vacuum gauge and see what it reads. There is a lot that the vacuum readings can tell you, from a general leak to burnt valve, etcetera. Quote Selected
5.0 running terrible Reply #13 – June 16, 2008, 05:19:44 PM i think i fixed the problem finally. this morning i decided that i was gonna go and try some stuff and i messed with the "salt n' pepper shaker" connections and squeezed the female plugs to where they were smaller and spread the male ends to make them larger so they fit better and that didnt fix anything. the last thing i tried was i unplugged the throttle position sensor, and it started and ran fine. i plugged it back in, started it and it ran like again. so then i started it with it unplugged and while it was running i plugged it in and it started bogging and it died. so i think with all this that the sensor is the problem. Quote Selected
5.0 running terrible Reply #14 – June 16, 2008, 06:51:43 PM with the throttle position sensor unplugged will it cause the car to bogg at part throttle? i was just looking over and i was wondering if the bogging problem will be fixed when i replace the sensor or is that going to be another problem? also i noticed that there is a loud sucking sound coming from a white box thing under the dash just above the steering shaft. could this be another problem coming from the sensor being bad or is this, yet again, lol another problem? i am on a limited budget and i cant afford to keep replacing everything i think is the problem and i still have to get a radiator or get mine fixed before i can actually drive it. so any input will be appreciated. and i know i still need to get the codes but i still havent gotten to drive it to town because im afraid its gonna overheat Quote Selected
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