Car Sputters While Accelerating

[DOUBL3 D]

rpms go up as car accelerates, it just does it in a bogged down/stuttery fashion. It back fires on occasion now if you floor it (i try not to with the cars current state unless im merging on the interstate) Its not a boost leak i as im holding a steady 6.5psi.

Thanks for the diagrams also.

 

[D.J.T.]

rpms go up as car accelerates, it just does it in a bogged down/stuttery fashion. It back fires on occasion now if you floor it (i try not to with the cars current state unless im merging on the interstate) Its not a boost leak i as im holding a steady 6.5psi.

Thanks for the diagrams also.

Hmm. Maybe it has problems getting the fuel to the engine?? Have you ever changed the Fuel filter??? & by backfire do you mean flames in the exhaust or a MISFIRE.

 

[DOUBL3 D]

Hmm. Maybe it has problems getting the fuel to the engine?? Have you ever changed the Fuel filter??? & by backfire do you mean flames in the exhaust or a MISFIRE.

it sounds like a boom. seems like it might be leaning out

 

[boostcraver]

To the Op, I have been having this problem as well. I have narrowed it down to a fuel delivery problem. Checked all grounds, the coils, cps, tps, replaced plugs, wires, and did the silicon vacuum hoses. Also replaced a problematic upper/lower intake manifold gasket, and re-verified the cam/crank timing with a timing light. I haven't had the chance to test the fuel pressure as the car is down with bad turbo/HG, but the fuel system is in need of some attention to say the least. Fuel pump was used when installed, fuel filter is the factory unit, injectors were leaking (not now), etc you get the picture. I have the funny feeling that when I get the fuel system right, this problem will go away all together. Just my .02 cents. Your results may vary.

 

[boostcraver]

ok so i checked and i think i have three codes the codes read as follows (-=light on and _=light off) ___-_-__-__-_-_-__-__-_-_-_-_-__-___ then it loops back. i THINK this means i have code 21,31, and 51 which are oxygen sensor signal (im guessing because previous owner installed test pipe), air flow meter (my apex'i intake?), and switch signal which i think is because i left the car in gear and it will throw this code if you leave it in gear while running diagnostics. the only thing i could think that would be different is how the begenning of the loop would start which would mean i would also throw the code for RPM pulse or something in which case it said check distributor, which would make sense because i thought ignition was my problem. I dont think the loop makes sense though because the last part would make no sense.

any ideas? new plugs and wires will be here friday. does anyone know where a vacuum line/hose diagram might be? thanks in advance

As far as the intake goes, I have experienced an afm code consistently when using an aftermarket air filter of any kind. I have a friend who set his up with an extra length of 3" pipe running into the front inner fender by going thru the hole under the pass. side headlight. He no longer has the trouble code since doing this. I guess it helps the afm make or read the vortex better or smoothes the air flow in some way. IDK, but he's code free and that's all that matters! LOL!

 

[D.J.T.]

it sounds like a boom. seems like it might be leaning out

Id change the fuel filter if you haven't already. Changed mine & dark gas just kept pouring out of it & if you've never changed yours ill guarantee it'll probably clogged. & leaning out, um sorry but i don't really use those terms so do you mean like it has TOO much gas? or its like short on gas. it Really sounds like a fuel delivery problem. Are you running stock or what are your upgrades?

 

[DOUBL3 D]

i think its leaning out, which is where there isn't enough fuel, which would be a delivery problem. i bought a new fuel filter last night and am going to put it in as soon as i post this. will update soon

 

[D.J.T.]

i think its leaning out, which is where there isn't enough fuel, which would be a delivery problem. i bought a new fuel filter last night and am going to put it in as soon as i post this. will update soon

Ahh yes then, Go for the Fuel Filter. Those filters always come out clogged or extremely dirty. The gas looks like dirty oil from a distance. & for the Supra its in a tough spot between the tank & the differential.

 

[DOUBL3 D]

Ahh yes then, Go for the Fuel Filter. Those filters always come out clogged or extremely dirty. The gas looks like dirty oil from a distance. & for the Supra its in a tough spot between the tank & the differential.

is there a tutorial of DIY for this anywhere?

 

[D.J.T.]

is there a tutorial of DIY for this anywhere?

Not sure but if you want i can take some pictures of its location. you'll need like a 14MM wrench & others if i remember correctly & lots of rags for the gas thats going to spill.

 

[DOUBL3 D]

Not sure but if you want i can take some pictures of its location. you'll need like a 14MM wrench & others if i remember correctly & lots of rags for the gas thats going to spill.

that would be greatly appreciated. i have the service manual but it doesnt explain where its at or anything about how to change it, i scanned it over a few times and didn't see anything about how to. can you not crimp the lines?

 

[D.J.T.]

that would be greatly appreciated. i have the service manual but it doesnt explain where its at or anything about how to change it, i scanned it over a few times and didn't see anything about how to. can you not crimp the lines?

Crimp?? I believe the lines are of Steel. I replaced mine a week ago & i remember a line of steel. Don't remeber any silicone lines.

Here are the Fuel Filter Location Pictures.

In Between the differential & gas tank

 

[DOUBL3 D]

Crimp?? I believe the lines are of Steel. I replaced mine a week ago & i remember a line of steel. Don't remeber any silicone lines.

Here are the Fuel Filter Location Pictures.

In Between the differential & gas tank

thanks for the pics, greatly appreciated. how much fuel came out when you did yours, just so i can get an idea, and is there any particular way to install it or do you just bolt in on and fire it up.

 

[D.J.T.]

Umm not so sure about an exact amount but you'll need plenty of rags & from the new filter are these things that screw into then new filter. put those on the old one to prevent it from spilling dirty gas. Ive heard people remove the fuel pump relay & crank the car so less fuel is spilled but ive never done that & i didn't do it like that but im just letting you know.

Well you take it out with the fuel filter bracket. take out the old one from the bracket & install the new one on the bracket. put the bracket back in place. connect the lines tight & crank the car. It will not start immediately so just keep cranking it & it will start eventually. Make sure its not leaking while its on.

 

[supra22]

The fuel filter has an inlet and outlet which should not be reversed...typically it is indicated on the filter itself either by an arrow indicating fuel flow or by Inlet/Outlet markings. Also, a spanner or flare wrench is worth its weight in gold when dealing with rusty fittings!!!

You can energize the fuel pump prior to ignition by shorting the Fp and +B terminals in the check connector (diagnostics). Just turn the ignition to the ON position and short the two terminals...you should then hear a hiss coming from the FPR.

 

[DOUBL3 D]

so you cant just take the old one off and put the new one off

 

[D.J.T.]

so you cant just take the old one off and put the new one off

yes you can. On the NEW filter it should have a side thats say IN. you connect the line that comes from the gas tank to that & the other end goes to the engine. Mine was simply disconnected with bracket & all (gas came out of course) then taken off from the bracket. new one installed on bracket & placed back in, connected how it was originally connected & its working fine now.

 

[DOUBL3 D]

ok so i changed the plug wires and that eliminated the problem of the sputtering. but i have a new problem: oil in the spark plug housing, my wires and plugs were DRENCHED especially on cylinders 4-6 towards the back. i dont think its the valve cover gaskets either because it doesnt look like its leaking at all. and when i start it and rev it a small amount of smoke (oil) comes from (if looking straight from the front to back) the back left side of the block. should i start a new thread? i want as much help as i can get

 

[DOUBL3 D]

bump for what to do

 

[D.J.T.]

No it can't be valve seals. Impossible....