Bogging Down Accelerating

[ShortyzKustomz]

For those that read my other posts. I acquired a 98 EB Explorer with a SOHC engine... It had been sitting for 5 years due to a locked up a/c compressor. Also the fuel pump was packed full of rust and the tank was horrible. I fixed the a/c system, Replaced the fuel pump, And got it running. Muffler was badly rusted so for now its straight piped. Heres my condition. It starts right up. Idles great. It drives pretty good. Once its warmed up some, If I try to accelerate more then say half throttle, It falls on its face. If I floor board it, It will stumble horrible, even pop and make all sorts of noise. I first assumed fuel filter, Since the tank was nasty, I cleaned the tank for hours, But knew there was still some trash in there. I drop the filter and sure enough there was rusty gas and some trash. New fuel filter, Start it up, Drive down the road... Same exact thing. If I keep out the throttle it will shift through all the gears and drive ok... I can rev it all the way without any issues. Until it does the bogging down thing driving, Then if I floor it to rev it, It struggles. So what are you guys thinking? Keep throwing filters on it till it clears up of course... I got some MAF cleaner. Gonna try that tomorrow night.

 

[my98nnj]

Does it accelerate ok when the engine is cold, then as it warms up, it falls on it's face?

 

[ShortyzKustomz]

Kind of seems that way, But I havent really gone out there with it dead cold and floored it either.

 

[my98nnj]

Sounds like a clogged exhaust system. If its "ok" when it's initially started then drops off as it warms up, that's the catalytic converter.

 

[ShortyzKustomz]

When I say warmed up... Not even all the way to temp. Exhaust flow is good. No changes in tone. Its straight piped out the back so I would tell a difference... Temp never goes hot even sitting at idle for 30+ mins.

 

[ShortyzKustomz]

When I say warmed up... Not even all the way to temp. Exhaust flow is good. No changes in tone. Its straight piped out the back so I would tell a difference... Temp never goes hot even sitting at idle for 30+ mins.

 

[Bodie]

Was the catalytic converter the problem? My 2000 5.0 is doing the same thing. It runs better at full throttle at open loop but at closed loop it bogs down at full throttle. I was going to change the fuel filter but I don't want to waste money throwing parts at the problem. The engine has 312,000 miles on it. It doesn't burn oil but does have a small oil leak at the rear oil pan seal( 1 quart every couple of months). Replies are appreciated.

 

[domct203]

Was the catalytic converter the problem? My 2000 5.0 is doing the same thing. It runs better at full throttle at open loop but at closed loop it bogs down at full throttle. I was going to change the fuel filter but I don't want to waste money throwing parts at the problem. The engine has 312,000 miles on it. It doesn't burn oil but does have a small oil leak at the rear oil pan seal( 1 quart every couple of months). Replies are appreciated.

Replacing the fuel filter would be considered required maintenance, not really ‘throwing parts at the problem’. Besides, you’re only talking $20 for filter and fuel line tool.

 

[Bodie]

Thanks for the reply.

 

[rasouth]

My brother-in-law had a similar problem with his car,,, idled okay, stumbled on acceleration, did not warm up quickly... He ended up taking the exhaust manifolds off and found someone had left a rag in the manifold from a previous repair. It blocked the exhaust from getting out and built up back pressure at higher revs.
Not sure if it fits your problems.

 

[CDW6212R]

Have you checked the fuel pressure since replacing the pump? Do that to be sure the pressure is at least 35-40psi with the FPR vacuum line temporarily off. How bad was the gas tank, how much corrosion of the inner surface was there? I have my 98 Mercury with a similar issue, the inner surface is coming off, and I think only replacing the gas tank will fix mine. The fuel sock was full when I had my tank out last to do the pump.

 

[ranger7ltr]

For those that read my other posts. I acquired a 98 EB Explorer with a SOHC engine... It had been sitting for 5 years due to a locked up a/c compressor. Also the fuel pump was packed full of rust and the tank was horrible. I fixed the a/c system, Replaced the fuel pump, And got it running. Muffler was badly rusted so for now its straight piped. Heres my condition. It starts right up. Idles great. It drives pretty good. Once its warmed up some, If I try to accelerate more then say half throttle, It falls on its face. If I floor board it, It will stumble horrible, even pop and make all sorts of noise. I first assumed fuel filter, Since the tank was nasty, I cleaned the tank for hours, But knew there was still some trash in there. I drop the filter and sure enough there was rusty gas and some trash. New fuel filter, Start it up, Drive down the road... Same exact thing. If I keep out the throttle it will shift through all the gears and drive ok... I can rev it all the way without any issues. Until it does the bogging down thing driving, Then if I floor it to rev it, It struggles. So what are you guys thinking? Keep throwing filters on it till it clears up of course... I got some MAF cleaner. Gonna try that tomorrow night.

When I first started driving my Explorer with a rusty tank I could not go more than 300-500 miles without changing the fuel filter if i wanted to run at speed...I mounted an electric fuel pressure gauge and could watch the pressure drop as the miles went by... I cleaned it numerous times and even had a radiator shop boil it out before using POR-15 in the tank and the tank still dropped rust into the fuel and through the new fuel pump into the filter...

Nothing fixed that except a new fuel tank...I guarantee if you drop the fuel filter you will find rust filling the filter and if you test your fuel pressure it will be lower than it should be...

 

[RandomNerd2000]

I'd change that filter if you haven't, my 2000 5.0 when it got to 270K or so, it had almost no highway power, it just dogged out. Did the spark plugs and had no change, when I remembered (my bad there) the fuel filter, it was so clogged up, I unhooked the engine side, and then the input side, and it was under full pressure. I'm subbing to this thread definitely, my brother has a 94 F-150 that does exactly this, I wanna see what it ends up being.

 

[CDW6212R]

Today's bad gas(ethanol mix) absorbs water within a year or two of time in the tank. If you don't drive a car much, it would be very wise to only buy real gas for it. Non alcohol gas can easily still be okay after years of storage, most places that costs an extra quarter or so per gallon.

 

[mechanical failure]

Was the catalytic converter the problem? My 2000 5.0 is doing the same thing. It runs better at full throttle at open loop but at closed loop it bogs down at full throttle. I was going to change the fuel filter but I don't want to waste money throwing parts at the problem. The engine has 312,000 miles on it. It doesn't burn oil but does have a small oil leak at the rear oil pan seal( 1 quart every couple of months). Replies are appreciated.

I have the and the same miles almost exactly. Same oil issue exactly. A month ago it started kicking like a pissed off horse after it got up to normal temperature. Thought it was a tranny problem still not sure. But it is throwing zero codes and no check engine light at all. But as I'm driving down the road it just kicks and thumps for no reason. No good advice could you some of my own?

 

[DintDobbs]

@mechanical failure The engine choking at temperature could be related to a variety of things discussed in this thread; check for exhaust blockage and fuel filter, etc. first, knock out the easy stuff.

The "kicking" and "thumping" only started recently, is that right? And also only when it's at operating temperature? If it was in the engine, there should be a code, so I'd start with the axles and work your way forward. Could be a leaky differential that seizes after driving a while, could be a dying drive shaft, could be the transfer case trying to lock if you have a 4x4. Does it behave differently while you are turning a corner or curve?

 

[Fix4Dirt]

welcome!