How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Jerry Your Own Question
Jerry, Master Mechanic
Category: Mercury
Satisfied Customers: 17220
Experience:  ASE Master tech. 30+ years mechanic, shop forman, service manager
Type Your Mercury Question Here...
Jerry is online now
A new question is answered every 9 seconds

1991 mercury capri has little hill climbing power. I replace

This answer was rated:

1991 mercury capri has little hill climbing power. I replace TPS, inner and out ignition module, new exhaust system, spark plugs & wires, coil, and new fuel filter. On level ground it moves okay,but any slight grade and its down to 25 to 35 tops! The rpm sometimes surge before it shiifts gears. I forgot to mention its a AT non- turbo.

Hello and welcome. Thank you for trusting us with your vehicle concerns, I will do my best to help you with your question.


What is the fuel pressure?

Customer: replied 4 years ago.

I don't see anything on the reply John.
Customer: replied 4 years ago.

I have not had a chance to take a spin to see if over night miracle has taken place on flushed job! O yeah I forgot to mention that I added another bottle injector cleaning on top of full tank of fuel.

Customer: replied 4 years ago.

Did I mentioned that I observed no vacuum leaks when Valvoline was flushing the system. My thinking is there should have been white smoking pouring out all gaskets and ports?

You have to see what the fuel pressure is and I 'm sure the exhaust, (being new) is clear.
Customer: replied 4 years ago.

Thanks for the come back, but I had one mechanic check the pressure after installing fuel filter under the hood. At that time he said it was O kay, but will get it check again.

If the fuel pressure is up to spec and the exhaust is clear and it still lacks power there is a good chance that the engine is getting low on compression, may want to check that too when the engine is warmed up, thanks
Customer: replied 4 years ago.

Thanks for pointing me in right direction. I Will let you know how it turns out.

Ok John, thanks. The fuel pressure should be,

Fuel Pressure 28-36 psi

You also may want to check it while moving and at a higher RPM.

If you do not require further assistance, kindly rate my service.


Jerry and 6 other Mercury Specialists are ready to help you
Customer: replied 4 years ago.

One more question would the access to fuel pump be under rear seat?

I'm asking just in case everything go south from here. Thanks for the advice, because I'm running out of electrical parts to replace! (ha, ha)

Sorry John, I just found your reply. Happy labor day. Yes the fuel pump is under the rear seat cushion.


  1. Relieve the fuel pressure as follows:
    1. Remove rear seat cushion.
    2. Run engine while disconnecting fuel pump electrical connector.
    3. Allow engine to stall. Fuel pressure is now relieved.
  1. Remove fuel tank sending unit.
  2. Remove two fuel pump wires from sending unit.









  1. Remove retaining clamp screw and remove clamp.
  2. Remove rubber retaining band.
  3. Remove fuel pump from sending unit.


  1. Install fuel pump to sending unit bracket and secure with retaining clamp.
  2. Install rubber retaining band.
  3. Connect fuel pump wires to sending unit.
  4. Install sending unit onto fuel tank.



Customer: replied 4 years ago.

Sorry about getting back late! I gave you excellent rating. I replaced fuel pump. Problem still persist, it seems to drive and shifts okay on level ground when it is warmed up from x-way drving but still lack power when climbing hills especially from a dead stop max. 30 mph and it seems to stay in low gear until it gets to a certain point of level then it might take off or the rpm will race.

The only other thing that would normally do that, (very low power on a hill) would be the compression of the engine if it were low. Sort of just weak. Hard to say though, without a compression test of the cylinders. The 1.6 wasn't really a power house when they were new, but a good engine. Nice car the 91 Capri and we want it to run best that it can.
Customer: replied 4 years ago.

Thanks Jerry for information. I have nothing to really compare the capri to, since all I ever own big V-8's and 4.0 six. I 'm trying this one from junk yard!

Is it possible for it to be a transmission problem. I will get compression check again but was told it was okay at one time. Thanks again I will

Customer: replied 4 years ago.

Thank's will keep you informed on progress. Excellent advice!

Yes, John, you want to be sure that it is kicking down when it's floored, (or going up a hill) and that it's not slipping of course. It just seemed to sound more like a low power problem. Then again, it's hard to say without driving it.
Customer: replied 4 years ago.

Hey Jerry! Thanks for advice on power loss. Replacing fuel pump was easy enough. Still not problem. I went back over a mechanic work and found the timing off. Shooting in dark without timing light I loosen
distributor turn clockwise marking each move until I found sweet spot.

Runs good now, thanks! Trans seems to be shifting better also. I am slowly making adjustments on idle with throttle cable and Idle screw.

Good Job John, that will probably run just fine when you get it just right. Really a nice little car and I expect that they will go up in value as the years go by. Thanks again and let us know if we can ever help you in the future.