1991 Ford Ranger Loss of power, noisy fuel injectors

Tiny
STINSON
  • MEMBER
  • 1991 FORD RANGER
Engine Performance problem
1991 Ford Ranger 6 cyl Two Wheel Drive Manual 100K+ miles

Strange problem. Started to experience a loss of power. Takes a long time to get the vehicle moving but will eventually get up to speed but any hill becomes a struggle. The engine runs fairly smooth, not like a plug wire is off but there is some slight popping or backfire noise when you let off the accelerator. I have done the obvious, new fuel filter, new plug wires, plugs are ok and maintains fuel pressure of 38 psi at the Schrader valve throughout the RPM range. There is a definite, loud clicking sound from the two aft injectors on the passenger side. I removed the connector at those two injectors and the clicking disappears without a noticable change in engine noise. I thought possibly injectors were plugged so I replaced all six. The new injectors did not improve the problem at all. When I put a meter to the connectors while running I get 12.85 volts. The other odd item is after the engine runs for a few minutes, the plug wires are very hot, too hot to touch. Any ideas?
Do you
have the same problem?
Yes
No
Friday, October 3rd, 2008 AT 6:37 PM

5 Replies

Tiny
JACK42
  • MEMBER
Resistance is what creates heat, maybe you do need new plugs. When you remove the 2 injector plugs, does the engine run different?
Was this
answer
helpful?
Yes
No
Tuesday, October 7th, 2008 AT 7:41 AM
Tiny
STINSON
  • MEMBER
I installed new plugs and it runs slightly better or maybe it's just my imagination. The plug wires are still hot and it still has the loud tapping noise. When I disconnect the aft two passenger side injector connectors the noise goes away and engine runs only a little rougher, almost not noticable. I also pulled the valve cover and removed rocker arms. The valves stayed in place so at least a valve is not broken at a stem. If you push the gas it eventually gets up to about 4k rpm and seems to run smoother. I also usually have to hold the pedal to the floor to get it started if it does not start on the first try. Seems like it is flooding. Can the ignition coil cause the hot wires as well?
Was this
answer
helpful?
Yes
No
Tuesday, October 7th, 2008 AT 10:01 AM
Tiny
JACK42
  • MEMBER
Possibly. Do you have nice blue spark or is weak and orange? Good compression on all cylinders?
Was this
answer
helpful?
Yes
No
Tuesday, October 7th, 2008 AT 11:06 AM
Tiny
STINSON
  • MEMBER
I do not have the ability to check compression, guess Ill have to go buy the tool. I am however thinking possibly bad valves I replaced the coil since it's only 20 bucks. The motor fired up easier but still have the noise. The odd thing is after running a few minutes and reving the motor, only the passenger side plug wires are hot, drivers side I can hold onto with no problem. The noise sounds like an exhaust leak but there isn't one. Motor is slow to respond when accellerator is pushed, response is not as immediate as it should be. I would say there is about a 2-3 second lag. Once it respnds it seems ok at high, (4K) rpm's. I am getting lost on whether it's a fuel issue cauing the electrical or visa versa. What are the chances it's the ICM? I don't think this is in anyway emmisiions related, it seems to be affecting only the two aft right hand cyliders. When it gets dark tonight I'll run it and look for any sparks were they shouldn't be. The dist cap is the only thing not new but the cap and rotor look brand new, no carbon, no signs of arcing.
Was this
answer
helpful?
Yes
No
Tuesday, October 7th, 2008 AT 4:14 PM
Tiny
JACK42
  • MEMBER
A compression test will help figure this out. It could be a head gasket blown between those 2 cylinders
Was this
answer
helpful?
Yes
No
Monday, October 13th, 2008 AT 7:36 AM

Please login or register to post a reply.

Recommended Guides