95 Intrepid 3.3l can't accelate please help

[shaallkie]

I can usually get up to 25mph no problem but above that and the car acts like it wants to choke out, then it doesn't want to shift gears(example the other day on a slight down hill grade and only because it was a down hill grade I got up to 50mph running around 4300rpms it wouldn't shift ). If I accelerate slowly some times it will shift then with out notice it will down shift(hard).
While in park or neutral when i step on the gas and hold it will rev up to 4000rpms then start to bog down or cut out dropping down to less then 3000rpms before i take my foot off. while the rpm's are dropping it sounds like it is starting to back fire.
There was a mil code for the fuel injectors but has not come back since i cleared it.
I have change the transmission fluid and filter and replaced the crankshaft sensor.
Any ideas

[shaallkie]

OK I believe the tranny was in limp mode.
The tranny is currently shifting fine but if you try to accelerate faster then grandma it the rpms start to drop as it cuts out. still sounds like it starts to back fire.


ANY IDEAS

[theFREAKnasty82]

on the back of the right cylinder head, there is a braided ground cable. Make sure it's secure to the head and not loose or corroded. I have seen that ground cable cause all kinds of problems. If that one is OK, check all your ground wires on the body to make sure they're OK.

[jeremy06]

I have some ideas/ things to check... map sensor voltage, tps sensor voltage...check to see if your cat converter isn't plugged. iac motor.... thats all I can think of for now.

[shaallkie]

I've swapped out the TPS and the Idle control motor and am working on getting a map sensor to try but voltage was within limits

[urclueless]

my thoughts are you might have a broken flex plate. the best way to determine this is with an old fashion timing light or an oscilliscope. symptoms of a broken flexplate... total lack of power, misfire/backfire, rev limit, struggle to accelerate. This happens A LOT. I've replaced at least a dozen over the past couple years.

get a real scanner and things will be a lot easier to fix

[shaallkie]

Thanks I'll try a timing light.

[urclueless]

inorder to use a timing light, you need to get #1 @ TDC, mark the crank pulley and mark the timing cover. (there are no factory marks) I use a timing light that has timing degree adjustement. at 2000-3000 rpm, the timing should be over 36° advance. The last cracked flexplate I came across had only 10° at 3000 and showed 20° retarded at idle. when I pulled the trans sure enough the flex plate was cracked and shifted

[shaallkie]

Do you think a bad engine computer could cause a timing problem? I was thinking of try to find one to try.

[urclueless]

Originally Posted by shaallkie

Do you think a bad engine computer could cause a timing problem? I was thinking of try to find one to try.

not likely, infact not at all.

[shaallkie]

I'm still having problems. car is back firing through the intake when you quickly increase rpm's above 2000-2500, and above 4000-4500 if increased slowly. I have not checked the fly wheel yet but would anyone Know if a loose timing chain would cause this? it's loose but has not yet jumped a gear.

[tempfixit]

My opinion is no a loose timing will not affect timing umless it has jumped a gear. You need to check the timing with a timing light to see if the flexplate is broken which I think from your symptoms is the problem.

[shaallkie]

Thanks for the info. I've still got the timing chain cover off so I think I will just lift the motor and do a visual inspection of the flex plate.