Full throttle issues. Advice please.

[Metta]

Sometimes you just have to bite the bullet and buy the test gauge and not a cheap one
The fuel pressure gauge kit
You will use it again
Just saying...

I’ve been giving a sealy one to use not sure how good it is but I get what your saying.

 

[C420sailor]

Yeah, this is either a big vacuum leak or your pump is going. You’ve got 0171/0174 codes. It takes a good amount of lean to make that happen.

 

[Metta]

Yeah, this is either a big vacuum leak or your pump is going. You’ve got 0171/0174 codes. It takes a good amount of lean to make that happen.

Thanks mate, I’ll order a pump if anyone has any option for me from rock auto? After 10 mins of sitting after a run it won’t start for a good few cranks of the key, which I’m guessing goes towards fuel pump.

 

[C420sailor]

Don’t throw parts at it. Test your fuel pressure first.

 

[Metta]

Don’t throw parts at it. Test your fuel pressure first.

I am going to test it tomorrow, it’s hard to get 5 minutes at work were so busy and I don’t have access to the keys.

What am I looking for when I do the test what PSI? Around 65 I think I read?

 

[donalds]

I am going to test it tomorrow, it’s hard to get 5 minutes at work were so busy and I don’t have access to the keys.

What am I looking for when I do the test what PSI? Around 65 I think I read?

60-69 psi is good in my book

 

[C420sailor]

Assuming you have a returnless system. My 98 is a two line system, and I believe that requires a lower pressure

 

[Metta]

Assuming you have a returnless system. My 98 is a two line system, and I believe that requires a lower pressure

What’s the way to tell mate?

 

[Pete Deering]

What’s the way to tell mate?

You can take a look at them. From the driver side front fender look for two stainless steel braided steel line with a connector. They will run from the top front of the engine to the frame rail below master cylinder. They go into a heat shield. And you Can look under the car at the fuel filter. The supply line go to the filler the return line and 1/2 steel vapor line pass by. They should all be clip In a black plastic support hanger in front of the filter ( between filter and engine).

 

[laker82]

Hey guys,

So I recently bought an explorer 1998 4.0 SOHC UK version with some small issues. I’m a mechanic and got most of them done such as idle valve, inlet gaskets upper and lower and few other things.

From day one I’ve had an issue with full throttle bogging out even at idle. ‘Overfueling I think’ so even at idle when half throttle car revs fine as normal right up the Rev range and back down, now when you open the throttle up fully I get spluttering. I have a video attached, the plugs have been changed 2 months back under a full service including fuel filter. The EGR is blanked off from previous owner but I don’t believe this would cause the issue.

Any help and advice would be perfect.

Carburetor, it would be fuel filter or weak pump. Would think along the same lines.

 

[Mbrooks420]

Carburetor, it would be fuel filter or weak pump. Would think along the same lines.

No Explorer ever came with a carburetor.

 

[Metta]

I didn’t record the readings guys, I was in a hurry when the car was idle pressure was around 62ish. Same at a fast idle and half throttle when I open the throttle up full where it bogs down the PSI drops a fair bit!

So I’m assuming it’s the fuel pump not taking the amount of fuel needed with more throttle?

 

[Mbrooks420]

Indeed.

 

[Metta]

Will this on be the correct one

 

[Steven Forzano]

As per previous post it only does it under load and when stationary only in full throttle, I have done the inlet gaskets 2 weeks ago.

MAF I’ve cleaned with Electrical cleaner and tried another, I’ve not tested fuel pressure as I don’t have a tool for that, I may be able to load live data on the diagnostics tho.

An old school way to check flow on your fuel pump is to disconnect at the fuel rail and cycle on and see how much output of fuel goes in to say a 7-Up bottle

 

[Mbrooks420]

An old school way to check flow on your fuel pump is to disconnect at the fuel rail and cycle on and see how much output of fuel goes in to say a 7-Up bottle

Entirely irrelevant way to test on a modern vehicle. Pressure is almost always the issue, not flow. At zero pressure I’m sure even a weak pump would put out plenty.

 

[Metta]

Entirely irrelevant way to test on a modern vehicle. Pressure is almost always the issue, not flow. At zero pressure I’m sure even a weak pump would put out plenty.

I put the pressure gauge on today it bud as showing 20 PSI on idle? And drops when reving… how is it running with that low of pressure

 

[Mbrooks420]

Extremely lean. Get the pump before driving it like that. It’s going to strand you soon anyways.

 

[Metta]

Extremely lean. Get the pump before driving it like that. It’s going to strand you soon anyways.

Is the one above the correct one from rock auto mate?

I’m going to order it as soon as you confirm I’m from UK so no room for error

 

[Mbrooks420]

I’m not the one to confirm it. I can’t remember, but I’m pretty sure I used the one above it. There’s several that will fit.