Im new to the forum. I have a 1996 Ford ranger xl with a 2.3 litre engine and a 5 speed manual transmission. And it has ran great since the day I got it! But starting about a couple weeks ago it has just been weak. It idles okay with a periodic sputter. But when I try to go it sputters and kicks. It seem like once I get it past 2 and a half thousand ( which I normally don't go past) it runs good, but any lower and the throttle is jumpy and it backfires. The weird thing is it won't die, itll just return to idle. Also sometime while idleing I can hear a humming\clunking sound. I have been checking many things and I'll have a list below. Also there is no check engine light.I'm looking for any more ideas on what else I should do. Thanks!

Replaced:
Fuel pump
Fuel filter
Air filter
IAC valve
Spark plugs and wires
New gas
Ran some injector cleaner

Checked
fuel pressure
Vacuum lines that I could see
Leaks between airfilter and throttle body
Voltage to fuel injectors

 

how long since you replaced the fuel filter

sputtering means the engine is not getting enough fuel pressure IE:: clogged fuel filter

 

I replace the fuel filter with the pump. Didn't help the issue. :\
Also I checked fuel pressure at idle -40 and it didn't drop when revving up the engine.
I do feel like its something fuel\air related though.

 

okay 2 things come to mind

if you have been running 87 octane fuel through your engine , then you have been burning ethanol

those older type of rubber fuel hoses are NOT ethanol tolerate , meaning the ethanol eats away at the rubber inside the hoses , thus clogging up fuel injectors ,

try running several cans of seafoam mixed in with esso 91 octane fuel 93 octane is better if you can find it , 91 and 93 octane fuels do not contain ethanol mixed in

my second guess would be that the converter is nearly plugged up

the catalyst honey comb screen inside the converter does break down over time

 

The owner before me cut the cat and added after market headers with a flowaster. So a cats no at fault here. But what you say about the rubber hoses breaking down and clogging the injectors could be the issue.Thanks for the idea. I think I'll try doing what you said. When you say several cans of seafoam, do you mean at once? And about how many can should I put it per about 20 gallons (full tank) of 93 octane gas? Thanks!

 

seafoam does not affect the fuels ignitability

i would run 2 cans of seafoam mixed in with a full tank of 93 octane of fuel

heck my snowblowers fuel tank is only 5 litres and i always dump a whole can in the tank at a time

the seafoam will dissolve the rubber particles , but it will take time

but i personally would just replace the fuel injectors , being a vehicle that old , they probable require replacement anyway

 

Last night i was checking sensors (by unpluging them and observing the change in idle speed and sound) and when I disconnected the tps (throttle position sensor) there was absolutely no change. I even drove with it disconnected and it drove the same way as before. So im gonna replace this sometime soon and ill let you know the results. If its not the tps then the injectors are my next target. Thanks for the help!

 

HMM nice catch on that problem

 

Just finished replacing the tps. I had to take the throttle body off and it was pretty dirty so I cleaned it also. I installed the new tps and put the throttle body back on it runs perfect now!

 

good to hear

my advice to you is though, you should replace those old rubber fuel hoses with the newer style ethanol tolerant fuel hoses

before the ethanol eats right through them

 

I always prefer fixing a problem before it leaves me on the road side. Ha-ha. So I'll look into installing some new fuel line :) thanks for the advise! Free advise is the best advise!

 

After replacing the tps it ran good for a day. But then it start acting like it usually does. I was wondering if you knew any information on the PCM. It just seems like it not mapping itself right or something. When it reset the PCM it runs good. But then after a couple trips it goes back to its normal ways of sputtering and stalling. Let me know if you have any more ideas and any advice about the PCM. Thanks

 

dis-connect the battery for 1 hour then re-connect it

the computer memory must be reset anytime you replace any sensor(s)

the PCM has nothing to do with engine operation , that is soley the ECM`s job

check the EGR operation with a vacuum pump , the vacuum solenoid may be jammed open slightly

 

clean the MAF sensor as well it may not be reading air flow and air temperature properly

 

I should be getting some maf cleaner whenni rent a vacuum test kit. I will be testing compression to make sure my engine itself is good. And from what I read because mine is a 96 I would need to use an obd2 scanner to reset the computer.

 

yes! the older model OBD1 computers use a small battery to maintain memory presets

so dis-connecting the vehicles battery will not work