Having problems with your 1999 Mercury Cougar ?

Car gets warm and starts hesitating on acceleration

\015 Car runs fine when cold but as i drive, within 15 minutes or so, the car gets warm and starts hesitating on acceleration and runs sluggishly. What could be the problem?\015
Posted / edited by AnonymousUser on : 15-01-2018

Answers :

Hi,
this could be something in the fuel pump. As the cold motor draws more fuel, it may just be just ok for the engine, but after it is warm, it draws less and may "suffocate" it that way. Same goes for air filter, take a peek if it is not ready for replacement. Has this happened suddenly, or has it occurrend during a long perion of time?
My car wont honk i cant find the correct fuse can you help me find it
Repair Help & Product Troubleshooting for 1999 Mercury Cougar

Tips for a great answer:

- Provide details, support with references or personal experience .
- If you need clarification, ask it in the comment box .
- It's 100% free, no registration required.

Suggested Questions/Answers :

Acceleration problem When the car is warm there is problem trying to accelerate. It sputters and shakes and in some cases it stalls out. It runs fine at idle speed. When I give it gas nice and slowly there is no problem with the motor but the minute that I give it more gas at a faster rate it starts to sputter and hesitate. Many people have been saying fuel filter, but this situation only happens once the car gets to a warm temperature. When I first start the car there is no hesitation on the ga


Possibly camshaft position sensor in the distributor, or weak fuel fump starts acting up when warm, or throttle position sensor. heat has a effect on sensors and electrical components in some weird and hard to find ways. ... 1994 Toyota Tercel

I have a 1986 Toyota Camry LE L4 2.0 Liter FI. When starting it has a real difficult time starting and when accelerating it hesitates. This gets better as the car warms up. The problem keeps getting worse each day. If I rev the engine for a minute or so the problem goes away. This too is taking longer and longer however. This morning the car eventually started, but while revving the motor it died and now won't restart. Any ideas? Fuel filter, EGR or something else? Thanks for your time.


Hello! A device called the Mass Air Flow sensor (MAF)is the #1 culprit...#2 is a stuck throttle body flapper valve...The MAF is bolted to the air filter housing outlet, it has a connector plugged into it, and a hose which goes to th ... Toyota Camry

Car gets warm and starts hesitating on acceleration


Hi, this could be something in the fuel pump. As the cold motor draws more fuel, it may just be just ok for the engine, but after it is warm, it draws less and may "suffocate" it that way. Same goes for air filter, take a peek if it is not read ... 1999 Mercury Cougar

Hi, Thanks for all the info everyone has given me so far...I now have a new problem..When Im driving my car sometimes when it gets up by 50-70 miles an hour...when i have my foot on the accelerator, it starts like kind of chugging, so i let mhy foot off the accelerator, then it stops, but when i get back up by 50 mph, it will start with the kind of hesitation...if i punch it and then get up to 80mph , then it is fine...so anywhere between 50mph and 70 mph...it has major hesitation, kind of feels


Check fuel filter ,air filter,egr valve,pcv valve try cleaning the last 2 with carb cleaner to get carbon off ... 1994 Buick Skylark

1998 olds regency with 3800. On startup car stumbles and hesitates a bit then smooths out. If starting when car is warm it is worse and sometimes won't start at all. Sometimes reving up helps to smooth it out. Sometimes it runs just fine. The times that it won't start is only when it is good and warmed up. The engine light is not on and there are no trouble codes present. I've had the control module(under coil paks) tested and tests fine. Also car has new cam sensor. I'm getting frustrat


... 1998 Oldsmobile Regency

I have a vw golf mk 4, when the car is warm it doesnt want to start, When its cold it starts first time with no problems. If i manage to get the car started when its warm and put my foot on the accelerator it loses power and then stalls. I have had it in a garage and they seem to think the problem is due to engine wear even tho my car has only done 69,000 miles, i have had it serviced every year so surely this isnt the problem, is it?


I had a similar problem on my '93 Golf at approximately 95,000 miles. It got so bad, I could not stop at a gas station for gas. I had to fill up gas cans using my wife's 2000 Jetta and refuel the '93 at home, otherwise I'd be stuck at the pump for at ... 1995 Volkswagen Golf

My 1989 300SEL the check engine light flashes intermittantly starting at around 70 MPH. If I accelerate it stops until I settle in at another highway speed. The car also hesitates slightly at the same time, and then picks right back up. Also have to really pump the gas to get the car to start (Check Engine List flashes a lot during this time also) once I get the car started it's fine.


The check engine light\015\012comes ON when the cars computer (the ECU) notices any kind of electrical\015\012problem in car. In some cases the check engine light comes on then turns off.\015\012In that case the exact error is not gett ... Mercedes-Benz 300-Class

Hesitation I have a 2003 Chrysler PT Cruiser... I get a "hesitation" on acceleration... Even though my car is 5 years old it has only got 26,500 miles on it... (I have seen the carfax report). I have had the car for a little over a year and it has only been doing this a few months... It has never stalled and never failed to crack.... Do you have any idea where I need to start to get this problem fixed. I am a female but I have worked on cars before from changing starters and alternators to hel


Sherry you may try an injector cleaner through it...it may be carbon build up on the valves ... 2003 Chrysler PT Cruiser

I have a 96 SW2 1.7 DOHC. When it reaches colder weather outside and once the car has been sitting for more than 8 or so hours, It has a hard time running, it starts and then immediatley begins to Choke and most of the time is dies, I Normally have to hold the accelerator down and run the engine at around 3000rpm to get to to keep running so it will warm up, Once its warmed up its perfect i can shut the car off and it will start back fine. I have Changed the Fuel filter, spark plugs, replaced tw


This problem has already been solved and accepted. ... Saturn SW2

I have a 96 SW2 1.7 DOHC. When it reaches colder weather outside and once the car has been sitting for more than 8 or so hours, It has a hard time running, it starts and then immediatley begins to Choke and most of the time is dies, I Normally have to hold the accelerator down and run the engine at around 3000rpm to get to to keep running so it will warm up, Once its warmed up its perfect i can shut the car off and it will start back fine. I have Changed the Fuel filter, spark plugs, replaced tw


Your car is equipt with electronic fuel injection. Sensors control the fuel/air mixture and alter depending on the conditions present. You have sensors that detect engine temp, outside temp, humidity, and air pressure (altitude), to provide the per ... Saturn SW2

When I start my car there is gas smell and it has poor acceleration. The acceleration gets better as the car warms up... The car also idles rough.I recently had an oil change I also changed the spark plugs with platinum tip, I also changed the PCV valve and air filter. The car also shakes while idling mind u the shaking diminiished a lil after the minor tune up.. Any ideas??


The gas smell makes me think EGRS (Exhaust Gas Recirculation System) check all your Vacuum hoses, start at your charcoal canister and work backwards.A vacuum problem explains your conditions at least... ... 1995 Nissan Maxima

Hey there my name is victor and i got a nissan maxima 97. The issue with it its rather strange, after the car gets warmed up, the car starts having problems, when the revolutions are to slow. While making wating for the street lights or anything that keeps me from accelerating the car shakes quite a bit and it turns down, some other times the car just doesnt respond, you can push the pedal to the metal and it wont accelerate no matter what, until it "unfrezes" In the repair shop they changed


Sounds like your Mass air flow meter is bad. Seems like they changed your knock sensor when they should've warmed the car up to figure out it is the MAF sensor that's bad. It's a common problem on that generation Maxima. ... 1997 Nissan Maxima

1985 fleetwood 4.1L rwd fuel injection the car hesitates severely when I first accelerate and almost seems to back-fire but gets better after warming up, but still not perfect. if I jump into nuetral while accelerating it revs rpm up fine (no hesitation)and only in gear does it hesitate. any ideas


... Cadillac Fleetwood

Shuts off when its hot and usually after fueling up.............acts like its not getting fuel....................usually after fueling up when car is hot............leave the car sitting for a couple hours and it starts back up.Usually upon starting you have to step on accelerator and let it idle up and warm up.


I would replace the crank sensor and never pack fuel into your gas tank. First click when full stop pumping gas. Next time it does this pour or spray some water on the crank sensor and see if it will start, if so problem solved. ... 1997 Oldsmobile 88

1998 Civic, Cold start, idles fine. When car is warm idle speed increases then decreases over and over again from about 600 rpm to 1100 rpm. once warmed up and driving throttle becomes on-off switch...motor accelerates and slows depending on throttle opening. runs smooth until I get stuck in traffic or a long stoplight. I shut motor off when coasting or at rest, re-start, runs smoothly again. Problem increases when weather is at or above 40 degrees F.


... Honda Civic

I have a 1991 Celica ... starts and idles great....no codes nothing. But when you try to accelerate it hesitates and will **** the car around....almost like it wants to stall...or its not getting enough fuel...... if you feather the gas it will get you up to speed ... but you have to accelerate slowly.... barely touching the gas.....if you floor it .....it will not take off either it ....noo smoke out of the tail pipe.... seems to run clean ..... just no power to take off


This seems like an air fuel mixture problem. ... 1991 Toyota Celica

I have a 1993 Toyota 4Runner that has been giving me problems ever since purchasing it a month ago. After a terrible oil leak we found that it had leaky head gaskets and paid $1800 to replace that along with the timing belt and water pump. Now, after getting it back from the shop a week ago, it is making a knocking noise from the engine when started & when accelerating (speeds up with acceleration) which starts pretty loud at first and seems to calm down slightly when the car is warmed up. We al


A 1993 Toyota 4Runner Water Pump is driven by the timing belt. Timing belt must be correctly positioned and then the timing confirmed once the job is complete. Based on your question, I would say the timing belt or timing is not correct. ... 1993 Toyota 4Runner

Acceleration problems I have a 1997 Chevrolet Blazer with the 4.3 "W" engine and auto transmission. Recently I started having problems with acceleration, cold the vehicle will accelerate to full throttle with just a slight hesitation but as the vehicle warms up the problem increases to the point that just a slight acceleration causes the vehicle to bog. While driving it will get to the point that the vehicle will hardly run, it runs smooth but you cannot give it any gas. I can stop the vehicle a


It could be excessive play in the distributor shaft. Or even a collapsing rubber fuel line. ... 1996 Chevrolet Blazer

When I am driving, and usually only while accelerating, my jeep's back right tire seems to be grinding and makes the car shake a little bit. It is not loose and this has only started happening in this snowy weather, after a lot of use of four wheel drive. Also, sometimes when reversing, I hear a crashing sound when I first accelerate after changing gears. There is also sometimes hesitation when accelerating. Any hep would be great! I have an appointment scheduled to get this all looked at, but


... 2003 Jeep Liberty

I have a 2005 pontiac grand prix 3.8 standard v6. this problem is so annoying seems worst if i don't let the car warm up. when i pull off under light acceleration the car chugs and shifts hard. i have to stop, turn the car off and back on and it will be fine. i also notice sluggishness and seems like it's not giving enough gas when you start it up, sometimes it will struggle like it's not getting enough gas for about 5 seconds. no one can figure this out or "duplicate" this issue but it's h


... 2005 Pontiac Grand Prix

I have a 2005 chevrolet impala v6. In the mornings I go out and start the car to warm up, when I go to get back in the car after warming up the fuel smell is very strong inside the car. After I get going down the road the smell goes away and doesnt come back until I start the car again to warm up. Do you have any suggestions?


You probably have the same problem i do with my car. My fuel regulator is leaking. I have to go have it replaced. It has taken us a year to find the problem because after the car is warm it doesn't leak. Good luck with it.....my car is the same y ... 2005 Chevrolet Impala

Vw polo, 1.4 petrol, 1996. when slowing down revs drop and car stalls and can be difficult to start again. when driving it can suddenly get abit jerky, no power from accelerator then loses the revs and stalls. it starts fine from cold its just when its warmed up abit and driving. any ideas and solutions would be appreciated. thanks


HOT/WARM START ISSUE\012\012 \012\012Its\012a hot start issue.\012\012Can\012be related to low fuel pressure or problem with crank sensor.\012\012 \012\012Also\012it c ... Cars & Trucks

2001 Hyundai XG300 - No codes show up. Regardless of speed or gear, acceleration hesitates, especially climbing up a hill or from a slight incline from a start. If keep gas pedal depressed all the way acts as though its not getting enough gas, or enough air and feels like car is just 'floating' without any power, then suddenly 'kicks in' and accelerates like 'bat outa ....' from 3,000 - 6,000 rpm.


Check the fuel filter to see if the fuel filter is restricted,if so,replace it,if this does not help,have the fuel pressure checked to make sure the fuel pump is pumping enough fuel pressure. ... 2001 Hyundai XG300

Hsitation I have a 96 jeep cherokee that hesitates and stumbles during acceleration only when i start it then it runs fine until i shut it off again. Ive gave the car a full tune up and changed the fuel fuel filter and had the the pump checked by a mechanic that said the car runs fine which confused me. he didnt fined anything wrong with it until i took him for a ride .so then he told me to drive it until it gets worse so they could pinpoint the problem. but i been driving for months same prombl


If it only does it when you start it cold its not the converter when a converter is going bad or restriced it acts worse the long the car runs i would replace the coolant temp senor for the fuelinjection system it won't set a code but it can read the ... 1996 Jeep Grand Cherokee

It feels like gas isn't getting to the engine. sometimes (usually at a complete stop or starting to accelerate) the car hesitates to go and jerks forward. Other times the car is driving along and the check engine light blinks, when this happens the power to then engine feels weak.


Have the fuel pressure checked- this would determine if your fuel pump is working properly. Its really easy if you have a gauge. you might be able to rent one at a part store. or it could need a new fuel filter ... 1996 Audi A4
  • Start your question with What, Why, How, When, etc. and end with a "?"
  • Be clear and specific
  • Use proper spelling and grammar
all rights reserved to the respective owners || www.carrestorationshop.com || Terms of Use || Contact || Privacy Policy
Load time: 4.1921 seconds