My 94 Ranger XLT with 150k miles on a 4.0 with automatic trans hesitates every time I try to accelerate. Its so bad It takes 4 or 5 seconds to get going at a stop light. I get honked at all the time. When at speed and I try to accelerate, it slows slightly for about 2 or 3 seconds before finally getting power. No check engine light. Also, though it might not be related, it sometimes loses power at freeway speeds. It doesnt die it just starts slowing. The check engine light will come on briefly then go out. I dont have a meter to check it. And Autozone and O'Reillys wont lend me one to take with me while I drive. It also takes longer to warm up. When I first start it it will hardly idle. It coughs and sputters and sometimes dies. I try pumping the gas peddle to keep it running but it doesnt help. After it warms up it idles fine.
Here is what I have done so far with no success:
Changed Air filter, spark plugs, spark plug wires, fuel filter, fuel pump.
I also sprayed Seafoam into the intake manifold as per the instructions on the can.
I'm broke so I cant take it to a shop.
Please help me. I thank you in advance.

 

Can you tell me who moderates this forum? I posted a new thread last Thursday, but it still hasn't been approved. Thank you!

 

Please, can any one help me? I see my thread has been read a lot but I have no suggestions.
Thoughts?

 

Hi,

OK first you need to be a bit more specific.

"hesitates every time I try to accelerate" = ??
Does the engine buck and bog down or do the RPM increase normally but truck doesn't move forward matching RPMs
This would be a torque converter/transmission problem
have you checked fluid level in trans.

Fuel injected engines use air flow to control idle, on a Ford that is the IAC(idle air control) Valve, computer runs this, IAC Valve can get dirty and stick, it can also fail.
It is easy to clean, look here: http://www.explorerforum.com/forums/...ad.php?t=84220

When you start a cold engine the computer looks at the coolant temperature using the ECT sensor, if under 100deg computer will set idle at approx 1,100rpms, as this sensor warms up fully idle will drop down to about 700 on an automatic.
Your ECT sensor could be telling the computer the engine is already warmed up, so computer never sets high idle and engine stalls or runs rough until it actually warms up.
There are 2 temp sensors just above thermostat housing
The one with 1 wire is a sender, only used by dash board temp gauge
The 2 wire one is the ECT sensor, and it can be tested with volt meter, key on, engine off, use a pin to pierce wires, when cold 1 wire will be 5 volts the other above 3volts, when engine is warmed up 1 wire will still be 5 volts the other under 1 volt

Most Auto parts stores can't read your 1994 computer(OBD 1) anyway, only 1995 and up(OBD 2)
But you can do it for free, read here: Ford Ranger - Testing EEC-IV Equipped Engines

Also google: how to read obd1 codes ford
Your '94 will use 3 digit codes.

Any time the CEL comes on a code number will be stored in memory, CEL doesn't have to be on and stay on to read codes.

Dirty MAF sensor will cause engine to buck and bog down, it can be clean


Bad TPS(throttle position sensor) can delay acceleration, this sensor can be easily tested with a Volt Meter and a pin.
Sensor has 3 wires, up and down
key on, engine off during test, pierce wire with sewing pin to test it
top wire will have 5 volts
center will have under 1 volt, .69-.99volt, with throttle closed
center wire will have above 4.5volts with throttle wide open

Older Rangers get stretched throttle cables, it happens over a long period so many don't notice.
Google: ranger throttle cable mod

Basically you put a couple of zap straps on gas pedal end of cable to shorten it back to stock length

Not your problem but thought I would mention it

 

Thanks RonD.
That was good info. I got it fixed. First when I say hesitation I mean the rpm did nothing when I stepped on the gas. No bucking, just no power.
I went with the easy fixes first and they worked. I cleaned the Mass Air Flow Sensor with some spray I got at O'Reillys. I also decided to clean the throttle body. The throttle body was very dirty. I think this was the problem. But one of the two cleanings fixed the problem. It accelerates nicely now.
Thanks for the suggestions. Im suprised no one else thought of cleaning the throttle body. Its fixed!

 

I'm having the same issue right now, I get honked at when the light turns green, I have all new plugs and wires and new coil pack, the mass airflow sensor is clean, I don't know what the issue is? Bad fuel injector or injectors? I put in 16oz of Seafoam with a full tank of gas earlier and it's still having the same issue

 

I had the same issue and even spent money taking it to a shop. It turned out when I filled up with e85 the bucking stopped. I believe it was in alcohol trim mode and as soon as you hit a little over 4000 rpm, the timing would drop to 10 degrees and feel like your engine was hitting a rev limiter. My fuel trims were off so I tried the e85 and no more bucking. I felt like burning it to the ground. I had a rebuilt engine and it would not run. If this works for you, then go for it. Now I have to figure out why it will not go over 4k on 87 fuel and should; may be a bad flex fuel sensor, but the fuel trims are ok on the e85. My Ford dealer will not work on a vehicle older than 2000. I think perhaps a update of the ecu would work this out too. A flex sensor is $500.00 and I am not paying that to find out.