running super lean/stumbling and loss of power

SON240sx Automotive
1

I’m pulling my hair out on this. It has become worse and worse over the past few months. I have checked all sensors, full tune-up, vacuum leaks etc.

I’m running so lean that my plugs are oxidizing with green on the electrode and they are white as a ghost. I know the engine is running hotter than ussual.

When I put my foot down on accelerator it either doesn’t have any power or shakes the crap out of my trying to accelerate. Top end over 4000 as no power either. It just doesn’t pull like it should.

I’m leaning towards fuel pump, or fuel pressure regulator.

This is an SOHC with 175k on it.

Any suggestions are welcome, I need to fix her before saturday :frowning:

Thanks,

Andrew.

2

nobody has any suggestions?

3

Sounds like a fuel problem… check your fuel filter. Start there and work your way through the fuel system…

4

Could be the MAF OR O2, make sure they are grounded correctly and are getting the proper feed.

5

everything in engine bay has been replaced in past year. Fuel filter and 02 have like 8k on them. I haven’t checked injectors/pressure regulator/fuel pump. Is there any way to determine the fuel pump is going
without changing it to found out?

Do you think a vacuum hose would make it this bad? I did check them all tho :?

I have never been so stumped.

6

Pump you’d only know if you put a pressure meter on the line. (unless it’s not working at all, but you said you get fuel so it has to be…)

7

ya I’m trying to find a pressure meter. Noone seems to have one I can borrow.

8

i had a stubling problem with my car aswell a while ago. It was stumbling very badly and would even stall on me sometimes so i hooked up a fuel pressure guage and found out i was only getting like 18psi of fuel pressure which is nothing so i checked the fuel filter and regulator and fuel pump and it ended up being the fuel pump was dying on me.

9

yeah mine doesn’t stall, but on idle or while approaching a light the rpms fo really low. Almost stall. I pulled the vacuum hose on the pressure regulator today with no success. So only thing left is fuel pump.

Do you have a fuel pressure gauge I can borrow?

10

no sorry man it wasnt my guage.
if you have eliminated the possibility of being a faulty regulator or fuel filter then its the pump for sure. I just replaced mine with a Walbro.

11

I checked the fuel pressure, thanks to Adam.
With the car on idle and the vacuum hose connected to the regulator I get 32 psi. But when I disconnect the regulator vacuum hose I get the same thing (32 psi). So, I swaped my regulator for my buddies, and the same thing, 32 psi with it disconnected. The FSM says it should be 44psi, which it isn’t. Look to be Fuel pump?

Andrew.

12

Fuel pump, fuel pump, fuel pump! It’s a single cam so it’s at least 14 years old… put in a walbro solve the problem and forget about it for the next 10 years or so. Or… keep ignoring it, have your motor detonate and put in an SR which will require a decent fule pump anyway :slight_smile:

-Martin.

13

lol my engine is mint. It was detonating nicely on the track on saturday hehehe. 94 octane and retarded timing saved it :lol:

I’ll get a walbro when I can afford one, grabing a used stocker for now.