need some info and help.

[grandprix92]

hey guys,

i have a 95 pontiac grand prix with 3.1 engine.

this just started out of the blue,

problem

the car started to miss fire under load, like if you hold the brake and give it gas it will miss pretty bad like shake the car and you can hear it out the tail pipe. also it only dose this under load, once going its find untill (2nd problem) you hit 2nd gear and around about 3k rpm it will lose power, like you can feel and see it on the tach struggle to gain speed,it will gain speed but you can feel and see somthing is holding it back

i cant pull codes,never could. anyone got any tips or ideas?

 

[FordMan77]

when's the last time it had new plugs and wires? How many miles are on the car?

 

[digitalgpbandit]

When was the last time you changed your spark plugs & wires? That's the first thing that comes to my mind

 

[mguzzo]

clogged cat?

 

[tomsteve]

When was the last time you changed your spark plugs & wires? That's the first thing that comes to my mind

and fuel filter

 

[grandprix92]

i just came in from replaceing the sparkplugs and fuel filter.

how can you test if the cat is bad?

 

[grandprix92]

dang it, the plugs and fuel filter didnt help.

 

[grandprix92]

sparkplugs and wires,fuel filter, and tps didnt work. lol

 

[bandook]

You really need codes. Does check engine light blink? Check fuse for obd2 port. Are all cylinders firing? On cold start you can carefully feel which ones are warming up.

 

[onxy]

Typically a bad cat will get worse as it gets hotter. You can also tell by the temperature difference before and after the cat after running 5min or so. It should be within roughly 20*, from inlet to outlet. If it's plugged it'll be substantially hotter on inlet side.

 

[grandprix92]

You really need codes. Does check engine light blink? Check fuse for obd2 port. Are all cylinders firing? On cold start you can carefully feel which ones are warming up.

cant check codes, its the obd 1.5, no body has one around where im at

 

[FordMan77]

Well, if you want to invest some money in a scanner I know my older Actron will read OBD 1.5 codes. In fact I bought it for that exact reason so I could scan my 95 Bonneville. I can give you the model# if you want to look for one. Works on OBD II stuff to up until the canbus stuff came into play.

 

[grandprix92]

Well, if you want to invest some money in a scanner I know my older Actron will read OBD 1.5 codes. In fact I bought it for that exact reason so I could scan my 95 Bonneville. I can give you the model# if you want to look for one. Works on OBD II stuff to up until the canbus stuff came into play.

yes please,

 

[FordMan77]

Actron CP9145 Super AutoScanner.

I would verify that it will work on the GP but I don't see why not. I just plugged mine into my 00 GP and set it to read codes for a 95 GP with the 3.1 and 4t60 trans and it was ready to go. In fact there were 3 options for a 95 GP it listed.