fuel issues

[ToPLeSS(e30)FeinD]

for some reason, since Friday, my 89 cabrio has decided to act like she is running out of gas on a full tank (bogging sensation as if fuel isnt getting to the cylinders). my initial thought was maybe a filter, so i check the filter and its fine. but then i notice that its not consistent in that it only does it when there is a load, i.e. 3rd, 4th or 5th over 3 grand and past half throttle. its not the same cylinder(s) misfiring so i dont think its a spark related issue and it doesnt feel like an afm, which iv had a lot of experience with. so i would imagine it would have to be fuel related. then today i managed to run into a friend and explained the issue while driving side by side and gave him a demonstration of the effects and the first thing he said he noticed was that it smelled rich of gasoline. then on the way home from the gym later that night, i realized a faint smell of gas coming out from the engine bay while at idle.

now i only have a suitable work place on mondays and wednesdays at school and i have not had the opportunity to run actual pressure tests or anything of that nature thus far. just trying to see if there is anyone thats been in this position before or might know where to begin looking. any POSITIVE input is appreciated and if u have any questions feel free to ask. thanks.

[jlevie]

Your symptoms are a good match for a fuel system problem. Since you have changed the filter the next suspects would be the pump or FPR.

[E30_fiend]

how did you CHECK the fuel filter? Or were you talking about the air filter? My car had the same issue with a bad fuel filter. Also kinda did it when my plugs were the bosch platinum 4 that the previous owner installed. Just because it doesn't feel like a misfire doesn't mean that your plugs aren't fouled. They will still spark, just not with as great an intensity as a new plug. If I were you, I would toss a set of new bosch copper cores in there and see if it fixes it. If not, you have new plugs. They are like a $1.25 a piece so it wont break the bank.


Taylor

[ToPLeSS(e30)FeinD]

I have yet to take out the plugs but i'll put it on the list. i checked both filters but i was talking about the fuel filter, and by checked i mean taken out, emptied and blown through to see if there is any resistance or a change in the way the car runs. im leaning towards pump but like i said i still have to run tests. thanks though.

[E30_fiend]

I'd do the plugs just because. And change the filter too. You could have gotten some really shitty gas that had sediment in it. Even though you can blow through, change it. It's cheap and easy.

[ToPLeSS(e30)FeinD]

ya. il do the plugs. havent changed them in a while. il wait on the filter till i run the pressure check and see what happens. cuz i just bought a new filter maybe a month ago an iv never run anything aside from chevron 89. but il run the test and get back to u tomorrow.

[Robert]

At idle it would smoke a little , that's what i was trying to tell you from my car . i saw white smoke and it smelled rich

[ToPLeSS(e30)FeinD]

huhhhh... great.. well il run some diags on it tomorrow and see what she does.

[ToPLeSS(e30)FeinD]

pressure test done. held pressure fine.. plugs look fine. but im still going to get new ones anyways pretty soon.. just waiting to get the time to. cap and rotor looks fine. and cps has been changed... now what?

[ToPLeSS(e30)FeinD]

So after a week the problem just went away. Then it came back with a vengeance and stalled my car out. I changed the spark plugs and wires just cuz it needed to be done and cleared out the fuel filter and after 2 days of sitting it fired right up. I let it sit for bout 10 minutes to warm up and then I took it to around 2750 and it choked out and stalled again. So my next move is to take out the fuel pump and make sure it's operating right. I'll keep u posted.

[ToPLeSS(e30)FeinD]

Can it be the fpr if the pressure test reads normal?

[ToPLeSS(e30)FeinD]

And the fuel pump seems to operate fine.

[jlevie]

And the fuel pump seems to operate fine.

What is the rail pressure when the engine is misbehaving?

Hint, tee in the pressure gauge and zip tie the gauge to the driver's windshield wiper. For a further clue, connect a test light to the fuel pump power lead and tie it next to the gauge.

[ToPLeSS(e30)FeinD]

Ya that's actually exactly what I did. And the gauge remained stationary as I went around the block. I don't remember what the psi read but I did it with my mechanic and I couldn't see it but he said it was running keeping stable. I'm about to pick up a temp pump to see if it reacts cuz I don't think it's the fpr as the pressure test reads fine.

[jlevie]

If the fuel pressure did not fall while driving, but the car experienced the starvation symptoms the fuel system isn't the cause. If the pump, FPR, or fuel pump relay were at fault the pressure would have changed.

Possible causes now are injector power or control signals, the DME, or AFM.