craigffb

Car has been running poorly for about two or three weeks. Bucking at ideal, hesitation under load. Changed out the filter...still the same. Sunday I filled it up and turned on the car and only had 25 PSI fuel pressure. Prior to that it was fine even when bucking. Pulled the vacuum line on the FPR had had no change at all and there was no fuel or smell of fuel from the line. I swapped out the fuel pump with an OE one I had. That netted me 0 PSI. Put the Walbro back in and now I still have 0 PSI. What next??? Could a bad FPR cause 0 fuel pressure?

craigffb

I forgot to mention...I could here both pumps running. But I didn't pull the line to see if it was pushing fuel.

RACEON

Look at your fuel pressure gauge and make sure its rubber seal isnt torn or blocking flow to the gauge.
Mine did this last night, 0 pressure yet pump was running and car ran like crap. Took the gauge off, and noticed the little rubber grommet inside end of gauge line was ripped and plugging hole. Fixed it and pressure showed .
Other than the gauge showing pressure, good luck.

craigffb

It's a hard mounted autometer fuel pressure gauge.

RACEON

Unmount it. Check the gauge to enure your tools are working first. Just a recommendation.

craigffb

The gauge is fine. The car will not start.

Slick-Z

Hey man make sure that when you take your readings that the fuel pressure constantly has a steay fuel pressure without the car running. Meaning turn the key over not starting it just letting the fuel pump engage. Then check your fuel guage. See what it is should be about forty one or two. Then wait and check it about five minutes later. The reading should be not lower than ten psi under what your initial reading was. If so you might have a leak in the system. I had a leak before and never smelled any gas. Anyway after that check then check with the car running.

SweetZRag

Verify diaphram in FPR is good by checking for raw fuel in the vacuum line connecting the right side on the intake manifold. If there is fuel, replace. Also, see if you get a puff of black smoke from tailpipe during start after sitting for a long period indicating fuel leaking through diaphram and pooling in intake manifold.

If these check out OK, make or buy a set of shutoff valves and install in line with the fuel and return lines where they connect to the fuel rail hard pipes at the back on the intake manifold. By turning these on and off after pressurizing the system, you can isolate where the leak is; fuel pump check valve, FPR or leaking injectors.

You can also remove the fuel rail with the injectors still connected and see if they leak when the system is pressurized.

RACEON

You said with two pumps you have ZERO pressure according to gauge, correct? This tells me the gauge may be bad.
If your main tool to check pressure is bad, and you dont want to check it, you are missing the point of the gauge.

craigffb

I understand what your saying. The car had 25 PSI and it held. Pulled the vacuum line on the FPR and nothing, it stayed at 25 PSI no fuel smell or raw fuel. I swapped out the pumps for the OE and had 0. I put the Walbro back in and still 0 PSI. The pump prims with the ign and will run if jumped but it won't build any pressure. I guess I need to pull the line at the filter and see if the pump is pushing fuel.

craigffb

OK I pulled the fuel line at the filter...couldn't get the line off the rail and yes I was using a line tool. The pump is pushing fuel. There is a steady stream. More like a **** stream then a fire hose. Weak pump?? Take note of my first post for symptoms before I swapped the pumps the first time.

Injuneer

But you still haven't checked the fuel pressure gauge?

craigffb

OK.....I have two gauges. 1 mechanical and 1 electrical (hard mounted Autometer) both read 0. Is that enough to eliminate it being the gauge keeping the car from starting or do I need to put a 3rd one on there? Fuel is getting to the rail as the mechanical gauge had some fuel in the connector but I can't tell how much because the lack of pressure.

Dtimekw

If you show 25psi then I would think there is a problem in the delivery side of the fuel system. I do not know for sure if 25psi is enough to run the engine but the normal reading is ~40-50 range. Did you use the jumper wire in the engine bay to check fuel pressure? It remains on while supplied with 12vdc. Sounds like you might want to get your pressure issue fixed then try to start/run the engine. Maybe disconnet the fuel line(s) at the tank and engine then blow air thru them to see if they are clogged?

craigffb

I do not have 25 PSI now. I had it before I swapped out the pumps the first time. 25 PSI was enough to get me home from the gas station. Now I have 0 PSI on two different gauges. The pump will prim with ignition...the pump will run if jumped and push fuel. The thing I need to know now is how much fuel should be coming from an open line with the pump on. If it's more than a **** stream then I have to assume the pump is not pushing enough fuel. If a **** stream is normal the the FPR is bad not allowing pressure to be built in the line. I may end up having to pull the return line off the rail and try and plug it to see if it will build pressure. But once again if someone can tell me how much fuel should be coming from the open line it would help.