I have this problem on my Fiero after the car is warmed up, the car wants to cut out. I have to release the gas, the engine studders, but always recovers. It becomes very prevalent at speeds around 40 mph. It also seems to be very consistant. The engine was rebuilt about 6,000 miles ago. The whole car had been gone through at the same time. The temp gauge is where is should be, the car is not heating even a little. Any help with this would be greatly appreciated!
No the car runs perfect cold, it only seems to be a problem when the car is warmed up and the temp outside is over 65. The car has a new coil, rotor, cap, plugs, wires, it got all that last year. I was hoping all of that would solve this problem, and for a while it did. None of the plugs are foulded out. Everything in the ignition is in almost new condition, except the distributer itself.
This is also a time where reading the engine data while running is valuable. I had a defective MAT sensor, and only found it when I ran the computer on it. (1987 2.5 DIS). There are so many issues to check.. Vacuum Intake manifold leak IAC stuck or troubled Spark plug issues, maybe wiring Fuel pressure under load Intermittent computer Hopefully this is what you signed up for, this is where it gets fun.
Check your fuel pressure. I had a similar issue in my 84 when it had the duke and it ended up being a fuel pump going bad, couldn't get enough pressure to the engine when at higher speeds or heavier throttle.
because the trans can cause this problem too. Like Iffy AT TCC solenoid can cause problem even stall the engine at stop sign/light.
Start w/ See my Cave, HE Ignition and pull tach filter connection. Pull AT connection too. Small square one on front of trans.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
This is also a time where reading the engine data while running is valuable. I had a defective MAT sensor, and only found it when I ran the computer on it. (1987 2.5 DIS).
Unless you want to start throwing parts at it, then you really need a scanner that can record data when the problem occurs.
[This message has been edited by edfiero (edited 05-23-2017).]
The engine finally threw a code. It threw code 13 which is the O2 sensor. This is strange because I put a new one on less than 6 months ago. I have a video showing what it is doing, but I am unsure how to upload it.
Auto or manual? Being an '84 I suppose it wasn't swapped and you have the 2.5? Did you set your ignition timing right?
It is a manual. It is the original engine, but it has been rebuilt. The timing was set by my engine re-builder. The only modifications that have been done to this, is the CAT has been removed and replaced with just a pipe. And it has a brand new GT style dual exhaust on it. I should have elaborated more, the issue only becomes prevalent after the car has been driving down the highway for about an hour on a 65 degree+ day. The car does not have AC, or cruise. When it got the new exhaust is when i replaced the O2 sensor. What the car will do is I will be driving down the highway about 45 minutes after I have left home and the car will start to die. I press on the gas and the rpm drops. I put it in neutral and stop, I try to press the pedal and all it does is cough and sputter. I let off the pedal and sit there with the car idling for about a minute or so, keep in mind the car idles perfectly even when this problem happens, it never dies from it. After a minute or so I press the pedal and it is back to normal no issues what so ever. It then will act up maybe 10 miles down the road or so and I repeat this whole process. If I park the car and let it cool down it works just fine when I start it back up and drive, but after it has been driving for 45+ minutes the whole thing happens again. As you can see, I absolutely hate driving this in town. If i go to accelerate, it happens to sometimes be when this problem presents itself and you have people honking at you but you cant do anything about it. After 30 seconds in town it comes out of this problem and runs normally. This does not happen at every stop light, it is random. Like posted earlier, it has thrown an O2 code.
