I have recently done a lot of work to my fiero. The owner before me had a mechanic do some work as well. My problem recently is intermittent stalling, only when the engine is warm and only right after starting it up. And when I do start it up, it starts up very quickly. It doesn’t smell of fuel and it is not leaking. When I prime the fuel pump, it is very audible and sometimes has crackling sounds.
I was told by the previous owner that he had replaced the fuel pump. When I had issues with fuel delivery, I replaced the injectors and the fuel regulator.
My current thought is to replace the fuel pump and filter because I can’t think of what else it could possibly be. Reaching out on the forum for other opinions, to see if I’m missing anything.
What is the fuel pressure when the engine is running? How long does the fuel pressure hold when the engine is turned off?
Take it from me, listen to Patrick. Check your fuel pressure and how long it holds pressure after you turn the car off.
My ‘86, 2.8L, V6 was giving me similar problems. I changed all the sensors, the TPS, MAP, etc. I “knew” it couldn’t be the fuel pump because I had installed a new one and I could hear the pump prime when I turned the car on. I was at point of replacing all the injectors. When my mechanic checked everything, he found low fuel pressure an a couple of intermittent vacuum leaks on some rubber connectors. The “new” pump was replaced with another new pump and the vacuum leaks corrected. Problem solved.
Not saying this will fix yours but before you start tossing money at the problem, check the simple things first.
Take it from me, listen to Patrick. Check your fuel pressure and how long it holds pressure after you turn the car off.
My ‘86, 2.8L, V6 was giving me similar problems. I changed all the sensors, the TPS, MAP, etc. I “knew” it couldn’t be the fuel pump because I had installed a new one and I could hear the pump prime when I turned the car on. I was at point of replacing all the injectors. When my mechanic checked everything, he found low fuel pressure an a couple of intermittent vacuum leaks on some rubber connectors. The “new” pump was replaced with another new pump and the vacuum leaks corrected. Problem solved.
Not saying this will fix yours but before you start tossing money at the problem, check the simple things first.
This sounds exactly like my problem…I’m having vacuum leaks too. I just did a fuel pressure test and it went to 40psi, and it very slowly went down to like 15psi and is holding that pressure.
This sounds exactly like my problem…I’m having vacuum leaks too. I just did a fuel pressure test and it went to 40psi, and it very slowly went down to like 15psi and is holding that pressure.
This sounds exactly like my problem…I’m having vacuum leaks too. I just did a fuel pressure test and it went to 40psi, and it very slowly went down to like 15psi and is holding that pressure.
We may have different definitions of "very slowly". Did the pressure start to drop from 40psi immediately? How long did it take to get to 15psi?
Took maybe 30 minutes to get to 15 psi, but it only took maybe 30 seconds to drop to 25 psi. and it actually continued dropping after 15... its been maybe two hours and now it’s at like 3 psi?
Took maybe 30 minutes to get to 15 psi, but it only took maybe 30 seconds to drop to 25 psi.
That seems like a rather rapid drop to me... but I don't know if that's the cause of your issue.
quote
Originally posted by saving_rossi:
My problem recently is intermittent stalling, only when the engine is warm and only right after starting it up.
Just for clarification... will you engine eventually stall while driving without needing to have first re-started it when warmed up? In other words, can you drive your Fiero indefinitely without it stalling... until you stop and then re-start it again?
Just for clarification... will you engine eventually stall while driving without needing to have first re-started it when warmed up? In other words, can you drive your Fiero indefinitely without it stalling... until you stop and then re-start it again?
Yes, I can drive it indefinitely, for now. I think I can hear the fuel pump whining intermittently though, which is concerning. Sorry for the late response
I think I can hear the fuel pump whining intermittently though, which is concerning.
And it'll whine when you know for sure that there's lots of gas in the tank?
My fuel pump will whine if I allow the gas to get too low. The fuel gauges in Fieros are notorious for showing a quarter tank or so when the engine is actually running on fumes.
And it'll whine when you know for sure that there's lots of gas in the tank?
My fuel pump will whine if I allow the gas to get too low. The fuel gauges in Fieros are notorious for showing a quarter tank or so when the engine is actually running on fumes.
I try not to let it get below the halfway point. I heard the whining on a 45 minute trip, right out of the gas station. It was showing about 80% on the gauge when I noticed.
It just feels strange to me because the crank is so short. It starts up so fast, I worry there’s fuel leaking from somewhere.
I’m going to try to get this done today or tomorrow depending on your feedback. I really appreciate your presence on this forum
I’m going to try to get this done today or tomorrow depending on your feedback.
Damn, don't put that kind of pressure on me. lol
It's a bit of a concern that the fuel pump is whining even when there's plenty of gas in the tank. It may or may not be a sign that that the fuel pump is faulty, and it may or may not be contributing to the stalling issues.
Is there a way you can induce the stalling (by perhaps doing what you mentioned earlier, by re-starting an already warmed up engine), and then immediately checking the fuel pressure?
Is there a way you can induce the stalling (by perhaps doing what you mentioned earlier, by re-starting an already warmed up engine), and then immediately checking the fuel pressure?
I tried doing this and couldn’t replicate the issue in a controlled environment..only while I was out on the road. Life got busy with college and so I decided to start the fuel system project to work on periodically.
Did the pressure start to drop from 40psi immediately? How long did it take to get to 15psi?
