1996 Mercury Mystique problem

Tiny
THEROKSHOWGUY
  • MEMBER
  • 1996 MERCURY MYSTIQUE
  • 4 CYL
  • FWD
  • AUTOMATIC
  • 210,000 MILES
When Im driving holding the gas pedal down the car bogs down and starts slowing. Goes real slow going uphill and speeds up slightly going down hill untill I let off the gas then push it again it'll kick and take off like normal. Sometimes I have to let off the gas quite a few times before it'll kick. Any clues what this is?
Wednesday, May 6th, 2009 AT 3:56 PM

9 Replies

Tiny
MERLIN2021
  • MECHANIC
  • 17,250 POSTS
Is the check engine light on? either way I would test the fuel pump pressure.
https://www.2carpros.com/car_repair_video/test_fuel_injection_pressure.htm
Go here and checkout our video.
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Wednesday, May 6th, 2009 AT 4:09 PM
Tiny
THEROKSHOWGUY
  • MEMBER
  • 10 POSTS
Yes the check engine light is on, the car is so old, im not sure what's wrong with it, it might be a fuel pump that thought did cross my mind, I changed the fuel filter, and it idles just fine, once it heats up it seems to idle rough the car vibrates, and sometimes it dies, but when the engine is bogged down it dies everytime I stop. I keep meaning to have a code checker put on it to see what it says, would a bad fuel pump or regulator show up on a code check test?
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Wednesday, May 6th, 2009 AT 4:19 PM
Tiny
MERLIN2021
  • MECHANIC
  • 17,250 POSTS
Depends, some can read live sensor data and lean and rich codes might tip you off, a fuel pressure testing gauge is better tho, if it runs worse after warming up, it could be an EGR or vacuum leak problem, Autozone will scan it free, post all codes retrieved here and I will have another look!
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Wednesday, May 6th, 2009 AT 4:22 PM
Tiny
THEROKSHOWGUY
  • MEMBER
  • 10 POSTS
Where is the fuel test port I can't seem to find it at all on the lines coming in from front or anywhere on my car, does it have a fuel pressure test port?
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Thursday, May 7th, 2009 AT 12:42 PM
Tiny
MERLIN2021
  • MECHANIC
  • 17,250 POSTS
Usually it's on the fuel rail Is this a 2.0 litre?
With Fuel Pressure Gauge WARNING: Always relieve fuel pressure before disconnecting any fuel injection-related component. DO NOT allow fuel to contact engine or electrical components. Remove fuel cap to release fuel tank pressure. Remove relief valve cap. Relief valve is located on fuel supply manifold. Using Fuel Pressure Gauge (T80L-9974-B), release fuel pressure from relief valve (Schrader valve). 1. If fuel pressure gauge is not available, disconnect electrical connector to IFS switch. For IFS switch location, see INERTIA FUEL SHUTOFF SWITCH LOCATIONS table. Crank engine for 15 seconds to reduce system pressure. Turn ignition off. Reconnect IFS switch connector. 2. 5/7/2009 src="https://www.2carpros.com/forum/automotive_pictures/62217_mercb_2.jpg" alt="https://www.2carpros.com/forum/automotive_pictures/62217_mercb_2.jpg" />



https://www.2carpros.com/forum/automotive_pictures/62217_mercc_2.jpg

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Thursday, May 7th, 2009 AT 2:49 PM
Tiny
THEROKSHOWGUY
  • MEMBER
  • 10 POSTS
I found the fuel line pressure port, and I hooked up a fuel pressure gauge to it, and turned the key to the on position I hear the pump engaging but no change in pressure, im guessing I have a bad fuel pressure gauge, I got the codes checked, and it came back with a bad fuel line code the guy testing it at autozone said it's probably the regulator, I ordered one, also it came back with an auxilary code, he said there's a misfire on 2 and 4 pistons, so im guessing a tune up will fix this, I got the spark plugs and im going to check to see if I have spark if not then i'll replace the cap and rodar distributor. Does this sound like it makes sense?
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Thursday, May 7th, 2009 AT 4:08 PM
Tiny
MERLIN2021
  • MECHANIC
  • 17,250 POSTS
What were the fuel pressure readings? Did start the car also and re check pressure?
https://www.2carpros.com/car_repair_video/test_fuel_injection_pressure.htm
Go here and checkout our video.
Use the specs I posted...
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Thursday, May 7th, 2009 AT 4:49 PM
Tiny
THEROKSHOWGUY
  • MEMBER
  • 10 POSTS
Yes and the needle, did'nt move at all. Which I assume it would atleast move, the car turns on just fine.
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Thursday, May 7th, 2009 AT 5:44 PM
Tiny
MERLIN2021
  • MECHANIC
  • 17,250 POSTS
Key on engine off should read 35-45 psi. Have the codes read and post the results please!
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Saturday, May 9th, 2009 AT 9:01 AM

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