94 Concord 3.5 fludder

[Frankalex]

Hi i have this 94 Concord ran great when i got it then all sudden it seem to bog down as i accelerate once it rolling at highway speeds it seems fine when i first start it it also runs little ruff untill i get up to speed almost like its flooding or starving for gas

i checked plugs they look fine i changed coil pack thinking that might be problem still the same i also checked vacume lines all looked good any suggestions would great

[pontiac69]

i am having the same problems with my 96 concorde. i changed many things but still nothing. i even had it at a dealership and they found nothing wrong and i had to pay them 75 bucks so they can hook it up to the computer.

[taillight]

Check fuel pump pressure.

[pontiac69]

is this easy to do? i am very mechanical but have no idea what to do on this car?

[taillight]

You need a fuel pressure guage. Find the fuel pressure fitting and put the guage on the fitting. start the engine and read the guage.

[jimnsulaw17]

this sounds similar to a problem i had with my old 94 3.5, except mine would sometimes stall as well and then not start until it sat for 10 -15 minutes.
i ended up having to replace the crank arm sensor and it worked liek a champ after that, no bog, all power. cost around $400 to have my mechanic do it, part was about $130 if i remember correctly.
good luck.
jim

[pontiac69]

i may have found one of the problems today. i took the car out for a drive and when i got back home the car had no power at all. i looked under the passenger side the the catalitic converter by the motor was glowing red. must be clogged. good reason there is no power.

[taillight]

A miss firing spark plug will also light up the cat because of dumping fuel into the exhaust. Fix the problem before you fix the cat.

[pontiac69]

Thanks for the infor. I was about to cut the cat off. Wasent going to be easy either. I wish i knew what the problem was in order to fix that and not the cat. The cat in question is on the passenger side. And the rear plug on the passenger side is I think a problem. When the car is running I pull the spark plug wire out of the plug and the motor does change. As if i remove any other wire while running the motor starts to bog down. The rear plug never changes. I pulled the plug and switched it with a different one in the motor and there is no problem with it in any other cylinder so i know its not the plug. I also changed the wire on that cyl. Didnt make a difference. I know the plug is sparking. I pulled it put it in the wire and started and it sparks just fine. I did change the coil pack a few months ago with a used on out of a junkyard to see if it fixes the miss problem. It did not make the problem any better or worse.

[taillight]

Do a compression test.

[Frankalex]

wonder how much work is it to change crank sensor cause iv changed wires plugs coil pack also i noticed i have mile per gallon readout on mirror except im reading per litre/100km and when im going down highway is sits at 7L/100 but when i take off and it bogging it up around 25-30L/100km think injectors need cleaning ? and its just flooding out

[Bob Mayo]

Changing the crankshaft sensor is pretty easy. One bolt. The part costs around $50. A bad sensor will cause car to run rough, stall, misfire and dump unburned fuel into the manifold/CAT.

[Frankalex]

cool thanks im just going replace crank sensor and cam sensor same time
for i can stop over this car but wife loves the car so im stuck fixing it

[clutch492]

Did this work out for you? Was it the crank sensor? I have one that is not starting up after a long drive. Wait overnight and it starts right up. I am leaning towards the crank or cam sensor. The fuel pump does not run after a long drive. I am fairly certain that the cam and crank sensor are both needed to signal the fuel pump to start. AM I CORRECT ANYBODY?

[denco]

Originally Posted by clutch492

Did this work out for you? Was it the crank sensor? I have one that is not starting up after a long drive. Wait overnight and it starts right up. I am leaning towards the crank or cam sensor. The fuel pump does not run after a long drive. I am fairly certain that the cam and crank sensor are both needed to signal the fuel pump to start. AM I CORRECT ANYBODY?

This thread is over two years old.

I had all the above problems with my 97 Concord.
The lower intake manifold was leaking.
I think yours may be electrical.
I had the ignition switch replaced under warranty for the same problem you seem to be having.