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1991 Mercury Topaz difficulty accelerating

My name is Joey, i Have just recently purchased a 91 mercury topaz 4x4. SHortly after purchasing it my wife and i noticed that it was having difficulty acceleration,(was needing to feather the throttle to eventually get the rpms up so we could go the speed limit. I changed out the fuel filter put fuel injector an carb cleaner in the tank. I check the transmission fluid its not burnt or anything neither is the oil. Im no mechanic but being inclined ive been going through my checklist(in my head) which sometimes ends quite bad but saw that the radiator cap was loose rusty the seals seemed really thin. I cant be spending tons of money at the moment and need a solution.if it could be as simple as the radiator cap or if i need to figure out my next play. Anything to push me in the right direction so i can get it fixed is much appreciated. Thank you

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You didn’t purchase this off Craigslist in Millmont PA for $2000 did you??

A radiator cap will have no relation to your lack of performance. The fact that it is carrying a 4 door 4WD car with 100 horsepower might be a contributing factor.

Fisrt off, are there any warning lights showing on the dash? Second, how do you “feather the throttle” on a fuel injected car? What happens when you mash the pedal to the floor?

Answer back but I’d say you have a lot of actual mechanic-ing to do to find the problems this car might have. Post back and we will try and help.

Throttling the gas is just pumping it. and no im in Idaho and purchased it with 90769 o.m. it was an older granny she rarely used it and now she cant drive. Her husband took care of it up until cancer took him…anyway bout the car. Its got new headers i tested the fuel pump tested out fine, i replaced yhe fuel filter ran carb and injector cleaner thru it. I just bought this yesterday. so ive barely had it for 24 HRS. I checked the transmission fluid still pink smells like tranny fluid, oil is good as well i replaced spark plugs and wires and just been goin down the list. after pumping the gas after stopping at bout 14-17mph she does fine until round 50mph where i have to pump the gas if i need to accelerate… the car didnt act up til like 20 miles away after buying the car, i went to a mechanic friend of mine but his state of mind and how he was rambling i knew it was all talk and intoxicants than actually being a mechanic at least i hope im not being the jerk just never hurts to have 2nd opinions esp when u can only fix a car if you know whats wrong with it.

You have a long road ahead to find out what is wrong with it. That is my point. Lots of things to test to find the actual problem.

So you need to find a sober, competent mechanic if you want this thing to run right.

The engine needs a thorough going over. I’d hook a vacuum gauge to the engine to see what kind of vacuum it pulls at idle and go from there. I’d guess the idle air control valve is clogged up or possibly failing. I’d suggest the EGR valve is in the same sinking boat. I’d check that with a vacuum pump and gauge, pull it off and take a look inside. It sounds like air is getting in where it shouldn’t.

I’d run a compression check as well. See the condition of the plugs - are they all firing? I’d replace spark plug wires, cap and rotor right off the bat. I’d even consider checking for a clogged catalytic convertor.

And you never answered whether this thing has any dash warning lights.


i thought i did sorry… my computer has been slow an dumb lately due to kids. service engine light comes on every now an then took it to a buddy who had a reader it gave me codes(11,33,87,41) he was in a hurry so didnt get to talk about much so im wondering to save on cash is cleaning injectors gonna help if the r even operable…i try to go from cheapest part to most expensive esp during the winter time i just have to get this thing safe enough for my kids

Ok, 11 means the ECU says OK. 33 is the EGR valve not opening.

87 is a fuel pump circuit problem. Likely a bad ground connection, maybe a bad fuel pump relay. 42 is a lean O2 sensor condition. An EGR leak can cause that. Start there.

Fuel injector isn’t gonna get the job done.

awesome ill definitely try ill message back toomorrow and let you know how it goes i will definitely start at the egr sensor and valve and will work from there will holler at ya tomorrow Thank u for the info and advice

The lean fault and the performance problem suggests that the fuel pump may be weak or the gasoline has spoiled. How old is the gasoline? Did this car sit for years before you bought it?

i put treatment in it idk how long it sat the air filter was pretty dusty when i cleaned it but i cant estimate off that i would saay at least a year or more from how the guy was talking bout his mom. i put carb an injector cleaner right away as soon as i paid for it and it had a 1/4 tank and i filled it up.idk if this helps but when stoppping she wants to die then when shes up to 14-20mph she does fine til bout 45-50 then have to pump it to keep her accelerating

I’m thinking you got some sort of EGR problem there OP. The EGR may be sticking, sometimes closed when it should be open, and sometimes open when it should be closed. Could cause some of these symptoms. You’ll have to figure out if the fuel pump code is actually a problem or not , that’s the first objective. A fuel pressure test could do that nicely.

im gunna be trying that in the morning never had a car with an egr prob, so of course have no knowledge of how to fix that talked to a couple ppl but when you said egr valve i looked it up and almost to the t describes exactly how my car is behaving. I really do appreciate the knowledge and advice,

EGR valve sounds like a good start. Pull the plugs and have a look at them too. Check the firing order if you have a distributor. 1 3 4 2 and rotation is clockwise if you have the 2.3 liter engine.

During hard acceleration the EGR valve is closed, there is no vacuum to open the EGR valve.

A EGR valve that will not open will not cause a great reduction in power. A EGR valve that will not close will cause the engine to idle terrible and stall.

I’ve had to replace the egr valve on my truck several times over the years. Never had to replace it on my VW Rabbit or Corolla though. As part of a routine tune-up I always test the egr valve on my vehicles by applying vacuum with a hand-held vacuum pump at idle. If that stalls the engine, I consider the egr valve to be working. Fords of that era (early 90’s) from reports here seemed to have some problems with the EGR control device, which is what decides how much vacuum to apply for the operating condition.

There’s several parts that could fail for the EGR system on the 2.3 L Vin X engine

  • egr control solenoid
  • egr vacuum regulator solenoid
  • egr tube
  • egr valve
  • egr valve position sensor
  • pfe sensor

There are SO MANY things that could be messing up this 28 year old slug. I’d try and find a mechanic to diagnose the problem(s).

And like has been said, these were slow when new.