New here and need a little information

[Donnphilpot00]

Hey guys. So I'm looking for a little Info. As of right now I have no exhaust on my truck (95 ranger xlt 3.0 2wd). The truck runs weak but runs. Now I'm trying build my own exhaust from the Y pipe on back. I went to the junk yard find me a Y pipe, is it better to have the rest of the piping as straight as possible or bent like the factory exhaust? I know some vehicles need the back pressure to act right.

 

[Donnphilpot00]

And also with me having no exhaust on the truck could that be the reason I can only start the truck by hold the gas pedal to the floor?

 

[Roert42]

And also with me having no exhaust on the truck could that be the reason I can only start the truck by hold the gas pedal to the floor?

Are your front O2 sensors plugged in. This will cause the truck to run very poorly.

Also, the truck should not start at all if you have the gas pedal pushed all the way to the floor. When you push the gas pedal all the way to the floor while starting, the existing cuts off the fuel injectors. So you may have some leaky fuel injectors

 

[RonD]

Welcome to TRS

FIRST, no 4 stroke engine runs better, or NEEDS, Back pressure, quite the opposite
That is a MYTH from people that built "free flow" custom headers and LOST POWER
Since the 1950's at least, car makers have designed exhaust manifolds to provide a bit of Scavenged Power, these create a lower pressure at exhaust valve that SUCKS OUT exhaust so piston doesn't lose as much power pushing it out, this occurs at a specific RPM by design
So "custom" DIY header would LOSE the scavenged power, unless it was design to keep it, and a MYTH was born

Most car makers designs do this at mid-RPM
You can get headers to get the lower pressure at lower RPMs, extra off the line power
Or Racing headers for high RPM lower pressure

If you are using stock exhaust manifolds then they will be mid-range, you can use any pipe that's the same size or larger than the stock exhaust and you will keep the same scavenged power
Straighter pipes will keep lower frequency sound, but still have to have the curve up and over the rear axle
As long as the pipe doesn't get smaller all will be well

Larger pipes do get a lower frequency sound, but no extra power


No, there are other issues with the engine, it should run and idle fine with no exhaust, but after warm up it will want to see O2 sensor feedback or will run really rough

In a 1995 Ranger check the fuel pressure regulator's(FPR) Vacuum hose, if it has gasoline inside replace the FPR
FPR is on the engine, will have the Return Fuel line attached and a Vacuum hose
If FPR is leaking then raw gasoline is being sucked into the engine flooding it out, so you need maximum air flow, gas pedal to floor, to keep it running

Also check the spark plug wiring if you are new to Fords coil packs
[3 4]
[2 6]
[1 5]
Are the matched pairs on the coil pack
So NOT
3 6
2 5
1 4

The 5 6 4 side often gets mixed up at the coil or at the cylinders

 

[dvdswan]

Welcome to the site.

 

[Donnphilpot00]

Are your front O2 sensors plugged in. This will cause the truck to run very poorly.

Also, the truck should not start at all if you have the gas pedal pushed all the way to the floor. When you push the gas pedal all the way to the floor while starting, the existing cuts off the fuel injectors. So you may have some leaky fuel injectors

I sorry I should rephrase it. I have to start the truck with holding the gas pedal down and then start playing with the gas pedal until it finally starts.....It has brand new injectors and there isn't any fuel leaking out on the top of the motor. So could the fuel go anywhere else if it's leaking? No the O2 sensor aren't hooked up since I don't have any exhaust pipes on the truck. The are still stuck in the holes on the old exhaust pipes I had to cut off because the bolts were so ate up from the rust.

 

[Donnphilpot00]

Welcome to TRS

FIRST, no 4 stroke engine runs better, or NEEDS, Back pressure, quite the opposite
That is a MYTH from people that built "free flow" custom headers and LOST POWER
Since the 1950's at least, car makers have designed exhaust manifolds to provide a bit of Scavenged Power, these create a lower pressure at exhaust valve that SUCKS OUT exhaust so piston doesn't lose as much power pushing it out, this occurs at a specific RPM by design
So "custom" DIY header would LOSE the scavenged power, unless it was design to keep it, and a MYTH was born

Most car makers designs do this at mid-RPM
You can get headers to get the lower pressure at lower RPMs, extra off the line power
Or Racing headers for high RPM lower pressure

If you are using stock exhaust manifolds then they will be mid-range, you can use any pipe that's the same size or larger than the stock exhaust and you will keep the same scavenged power
Straighter pipes will keep lower frequency sound, but still have to have the curve up and over the rear axle
As long as the pipe doesn't get smaller all will be well

Larger pipes do get a lower frequency sound, but no extra power


No, there are other issues with the engine, it should run and idle fine with no exhaust, but after warm up it will want to see O2 sensor feedback or will run really rough

In a 1995 Ranger check the fuel pressure regulator's(FPR) Vacuum hose, if it has gasoline inside replace the FPR
FPR is on the engine, will have the Return Fuel line attached and a Vacuum hose
If FPR is leaking then raw gasoline is being sucked into the engine flooding it out, so you need maximum air flow, gas pedal to floor, to keep it running

Also check the spark plug wiring if you are new to Fords coil packs
[3 4]
[2 6]
[1 5]
Are the matched pairs on the coil pack
So NOT
3 6
2 5
1 4

The 5 6 4 side often gets mixed up at the coil or at the cylinders

Yes I'm running the stock exhaust manifolds. So once I install the y pipe I can run it straight back as long I just go over the axle?

It also has a new fpr I haven't done a test on it yet but I'm going to. Yes I understand the firing order I have the book for the vehicle, I Don't have the original vacuum lines the old hoses cracked because they were the old hard plastic lines.

It's really doesn't run fine it's a really rough idle but it does idle doesnt cut off Is all I'm saying

 

[Donnphilpot00]

Welcome to the site.

Thanks I have visited this site alot I just finally got around to making an account.

 

[Donnphilpot00]

So if I plug in the O2 sensors will it run better even if they aren't screwed into the exhaust?

 

[RonD]

No
O2 sensors are not used, can't be used, until engine is warmed up, they need to be heated above 650degF to work
So after cold start computer runs pre-set air/fuel mix from memory, for at least 3 to 4 minutes, then it will "look for" O2 sensor signals

But a cold gasoline engine does need to be CHOKED, computer does that for fuel injected engines on cold start
Its base on engine temp from ECT sensor, for how much Choke to apply
As long as all the sensors except for the O2s are hooked up, engine should start, idle high(choke) and run smooth, for a few minutes

 

[Donnphilpot00]

No
O2 sensors are not used, can't be used, until engine is warmed up, they need to be heated above 650degF to work
So after cold start computer runs pre-set air/fuel mix from memory, for at least 3 to 4 minutes, then it will "look for" O2 sensor signals

But a cold gasoline engine does need to be CHOKED, computer does that for fuel injected engines on cold start
Its base on engine temp from ECT sensor, for how much Choke to apply
As long as all the sensors except for the O2s are hooked up, engine should start, idle high(choke) and run smooth, for a few minutes

So the engine isn't going to run right till I get the exhaust hooked up properly and properly install the O2 sensors into the exhaust, The reason the exhaust got messed up was because I wasn't thinking it threw very well and I cut the Y pipe in a very bad spot to remove the old exhaust manifolds (the bolts that connected the Y pipe to the manifold were so rusted away I couldn't get a socket on it) and then also the bracket on the back of cat broke off because of rust. I tried to put it back together but when I did the truck didn't start so I took the exhaust back off. The truck started again so Now I'm building a new exhaust from the Y pipe back.

I read another post from you on another thread talking about that and I went out and bought a new ECT sensor, but the engine still won't start unless I start pumping the gas pedal.

So I'm guessing I'm going to get the exhaust hooked up and then see what the engine does after that.

 

[Donnphilpot00]

Anyone think the MAF could be broken?

 

[Donnphilpot00]

Thanks fellas