Hey guys, I'm trying to get my car back on the road after some extended maintenance and it's giving me fits. Cold idle is steady but once it warms up it starts sputtering and eventually stalls. With throttle anywhere above idle it runs fine.
I hooked a fuel pressure gauge and vacuum gauge up to the engine (hooked the vacuum gauge into the brake booster port to eliminate that as the culprit). Here are my results:
Fuel pressure with the engine off, jumpering the fuel pump relay: 46 psi
Fuel pressure with the engine running at idle: 36 psi
Fuel pressure with the FPR vacuum line disconnected: 46 psi
Does the idle fuel pressure seem low to you guys? I thought it should be around 40 psi with the engine running? The pressures are the same whether the engine is cold or hot so perhaps my pump, FPR, lines, etc are ok.
The vacuum gauge reads 17 in/Hg at idle until it starts stalling out and then it flaps between 20 and 0 as it tries to keep itself running.
Now here's the really weird part. I disconnected the FPR vacuum line from the FPR (fuel pressure increased as expected) and then the idle evened out no problem since it's now getting a bunch of extra fuel pressure. But if I then put my finger over the vacuum hose it starts stalling out and then completely dies as before.
This has me scratching my head. I would expect it to run worse with that line disconnected and I have no idea why blocking that line would cause the engine to stall.
So far I've tried two different ICVs cleaned both of them out with carb cleaner thoroughly and checked both electrically. They both hum and show proper resistance on the terminals.
I checked the ICV plug wiring but I'm not 100% sure what normal values are here. I have battery voltage on the middle pin and it looks like 5V(?) signals on the other two wires.
The car has been sitting for a while but otherwise within the past year I've replaced:
Fuel Filter, FPR
Within the past 4-5 years I've replaced:
CTS, Cap + Rotor, Ignition Coil, Spark Plugs, Plug Wires
Has anyone seen anything like this before? I feel like I'm missing something but I'm not exactly sure what it might be.
I hooked a fuel pressure gauge and vacuum gauge up to the engine (hooked the vacuum gauge into the brake booster port to eliminate that as the culprit). Here are my results:
Fuel pressure with the engine off, jumpering the fuel pump relay: 46 psi
Fuel pressure with the engine running at idle: 36 psi
Fuel pressure with the FPR vacuum line disconnected: 46 psi
Does the idle fuel pressure seem low to you guys? I thought it should be around 40 psi with the engine running? The pressures are the same whether the engine is cold or hot so perhaps my pump, FPR, lines, etc are ok.
The vacuum gauge reads 17 in/Hg at idle until it starts stalling out and then it flaps between 20 and 0 as it tries to keep itself running.
Now here's the really weird part. I disconnected the FPR vacuum line from the FPR (fuel pressure increased as expected) and then the idle evened out no problem since it's now getting a bunch of extra fuel pressure. But if I then put my finger over the vacuum hose it starts stalling out and then completely dies as before.
This has me scratching my head. I would expect it to run worse with that line disconnected and I have no idea why blocking that line would cause the engine to stall.
So far I've tried two different ICVs cleaned both of them out with carb cleaner thoroughly and checked both electrically. They both hum and show proper resistance on the terminals.
I checked the ICV plug wiring but I'm not 100% sure what normal values are here. I have battery voltage on the middle pin and it looks like 5V(?) signals on the other two wires.
The car has been sitting for a while but otherwise within the past year I've replaced:
Fuel Filter, FPR
Within the past 4-5 years I've replaced:
CTS, Cap + Rotor, Ignition Coil, Spark Plugs, Plug Wires
Has anyone seen anything like this before? I feel like I'm missing something but I'm not exactly sure what it might be.
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