I am in hopes I am posting in the correct folder for this question. I will post it in the electrical section also. My problem is that I have a 92 t-bird with a 5.0 in it, it runs great and revs fine but it stumbles and will not accelerate when under a load. i have changed the ignition module, tps, fuelpump, regulator, computer, plugs, wires, cap, and rotor. i will try the distributor next but what else could cause the car not to run correctly under a load. thankyou for your help
I believe that on the '92 you can still use a code scanner. They are available at Kragen, or whatever popular auto parts place in your area. It sounds to me like maybe the mass airflow sensor or the equivalent on your year model. If it is, the code scanner will pick it up, and scan all the other engine sensors for faults. The '92 probably has at least 5 sensors, of which you have already replaced one, the TPS. But the scanner will save you trouble. Make sure you get the correct one for your car, they go by year/make/model.
i am not familiar with this type of car, but does it have an EGR valve? i just read an article from the latest "Best of Tech" magazine and it explained that an improperly working EGR valve can be a problem with hesitation and part throttle problems. the spring inside of the valve can wear out causing more exhaust gasses to blend inside of the intake manifold. an easy test to perform is to unplug the EGR valve and plug the vacum line going to the carb, and see if your problem goes away.
like i said before, i am not sure if your car has one or not, but it is a cheap and easy fix that you can diagnose for free.
I have been having similar problems with my 5.0 Mustang. A full diagnostic revealed nothing as far as the car's computer is concerned. A dyed in the wool Mustanger friend thinks it's the air bypass valve because sometimes it idles erratically. The engine studders a little on accelaration too, almost to the point it feels like clutch chatter. As far as I know there are only a couple of things other than a massive air-leak that can wreak havock on these Fuel injected engines. A bad TPS, egr, air-bypass valve, o2 sensor. Sometimes you just have to start throwing parts at it until it gets fixed as in my case the Computer does not recognize a failure. Mine does not do it all the time either which is why I have tolerated it for over a year.
I have been having similar problems with my 5.0 Mustang. A full diagnostic revealed nothing as far as the car's computer is concerned. A dyed in the wool Mustanger friend thinks it's the air bypass valve because sometimes it idles erratically. The engine studders a little on accelaration too, almost to the point it feels like clutch chatter. As far as I know there are only a couple of things other than a massive air-leak that can wreak havock on these Fuel injected engines. A bad TPS, egr, air-bypass valve, o2 sensor. Sometimes you just have to start throwing parts at it until it gets fixed as in my case the Computer does not recognize a failure. Mine does not do it all the time either which is why I have tolerated it for over a year.
If it doesn't do it all the time then it is a good chances it is your computer. Best way to check computer problems is remove the computer from it's mounting keeping the wiring harness hooked-up Now start the engine with your hand smack the computer if the engine runs rough then you have a cracked circuit board. Give it a shot costs nothing this will fix 50% of computer problems
If it doesn't do it all the time then it is a good chances it is your computer. Best way to check computer problems is remove the computer from it's mounting keeping the wiring harness hooked-up Now start the engine with your hand smack the computer if the engine runs rough then you have a cracked circuit board. Give it a shot costs nothing this will fix 50% of computer problems
you check a circut like a d battery stick your tongue on it.
smacking a computer can (and i say can) reveal a computer problem but it wont fix it i know thats not what you meant but thats what you typed
DO not disconnect the computer from it's mounting and then start the engine this will cause the computer to short out. I think it is the coil. It will act like a fuel problem. If there was a bad sensor you would be getting a "check engine" code light on the dash. Since there is none then they are doing their job. When computers go bad the engine will run FULL rich and run terrible until you stomp on it hard, then with the extra air coming in the engine runs much better. But as soon as you lift your foot a little it runs bad again.
Use an ohm meter to check the coil. You will need to look up the readings in a Motors Manual.
you can check a D battery with your tongue (or any other battery of that type)... just lick your finger and touch it to the - side and touch the tip of your tongue to the + side.
if it wasn't for that I would've never been able to beat tony hawk pro skater on my game boy advance without getting my lazy butt up and going to the store.
If the PCM has a internal failure it will go into FMEM mode (failure management effects mode). Timing will be set to 10 deg and fuel will go to a standard setting from the internal preset tables. Car will run but low power.
A PCM will not tell on itself, it will set no codes, and the only diagnosis procedure is to try a known good part.
The only other part that wont set a code on that application is the MAF. When it fails the PCM may give a lean code but not always. Diagnosis of the MAF is replace with known good part. From your original post the symptoms lean toward the MAF. but no guarantee. Anytime we saw a problem like that with no codes the first thing we changed was the MAF.
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