'95 3.0 Starts then stalls.

[Maui Cruiser]

1995 V6 3.0 SR5

Ran strong until a week ago, progressively getting worse on startup, engine fires, and then putters out and stalls. A week ago it would take a few tries before driving normally. Now it just keeps puttering out when going from ignition into idle. Pressing gas pedal doesn't rev the RPM's anymore (worked a few times). There is a loud WHACK coming from the air intake area occasionally during startup attempts. A friend said this may be from a misfire. Fuses seem fine. Going to try and fiddle around today to listen for fuel pump operation, double check fuses, etc. Vacuum hose checks, etc. Wish me luck!

 

[Ahlem]

When was the last time you changed your fuel filter?
Also check the rubber boot from the AFM to the Throttle body for bad cracks.
Check fuel pressure.

 

[DW4RUNR]

I'm thinking fuel filter replacement first, if still the same then fuel pump. Maybe spark plugs? Spark plug wires? If you have fuel pressure tester available check fuel.

 

[DW4RUNR]

FYI- replacing the fuel filter is a pain in the dick, tight spot, and usually the lines are tightened way too tight.

 

[Ahlem]

Crows foot wrenches and 3/8" socket extensions are your friend when it comes to changing fuel filters.

 

[BradG]

Any updates on this? Mine is doing the exact same thing and replacing the fuel filter didn't help.
I don't have a means to check the fuel pressure but I have new injectors sitting here along with a new pressure regulator so that's the direction I'm going.
Really don't want to have to drop the tank!

 

[Ahlem]

Can you keep it running at 1500 RPM?
I'd also check the AFM and the rubber boot between it and the throttle body.
If you have a massive air leak due to a cracked boot or forgetting to tighten the hose clamps, you will see this happen.
If it idles at 1500 for a minute or two and then idles better, you may have a temp sensor issue. We are chasing this at the moment.

 

[KidVermicious]

If it starts then dies immediately, look at your intake tube and boots to make sure you don't have a massive leak causing the AFM to not open. If the intake is fine, bypass the Circuit Open Relay to see if the COR or AFM might be bad. The COR takes signal from the AFM and tells the ECU that's it's ok to give power to the fuel pump, so anything defective in that circuit will cause the fuel pump to work while you're cranking and then immediately cut out when you release the key.

 

[Maui Cruiser]

There's no air leak that I can find. Fuel filter and fuel pump just got put in with a used vane air flow, igniter and coil, still same problem. Had someone check the relay by jumping the FP B+ and yep, same problem...:crybaby: What would cause this and not throw a code?

 

[Maui Cruiser]

FIXED>

Turns out it was the EFI relay malfunctioning.
In the diagnostic port - jump FP and B+ with a short wire. Runs normally.
This forced power to the fuel pump which the relay is supposed to provide.

Back on the road. Thanks y'all!

 

[BradG]

If it starts then dies immediately, look at your intake tube and boots to make sure you don't have a massive leak causing the AFM to not open. If the intake is fine, bypass the Circuit Open Relay to see if the COR or AFM might be bad. The COR takes signal from the AFM and tells the ECU that's it's ok to give power to the fuel pump, so anything defective in that circuit will cause the fuel pump to work while you're cranking and then immediately cut out when you release the key.

Just a quick update..I just replaced the COR and it's not dying anymore so I'm keeping my fingers crossed..

Thanks Kid!