3.2 Convertion problem

[94MTX3.2Swap]

Hey quick question i just recently got the 3.2 convertion done in my MTX SHO and its having an power issue when it hits high RMPs. its snappy when your in the low RPMs but once it hits high it feels like it loses power. Do you guys have any idea on what the issue might be? if you need more info ill do my best to describe what you ask. My brother thinks it has something to do with the exhaust because it dosent do it when its not conected but when you conect it the problem comes back.

:thankyou:

 

[redshoman]

depending on where you disconnect the exhaust, It may be a clogged cat converter not allowing th exhaust gasses out quicly enough.. causing to much back pressure. I would take a good look inside the y-pipe and resonator with a borascop.

 

[NovaSS]

or DEAD CAT

 

[SHODWN]

Hey quick question i just recently got the 3.2 convertion done in my MTX SHO and its having an power issue when it hits high RMPs. its snappy when your in the low RPMs but once it hits high it feels like it loses power. Do you guys have any idea on what the issue might be? if you need more info ill do my best to describe what you ask. My brother thinks it has something to do with the exhaust because it dosent do it when its not conected but when you conect it the problem comes back.

:thankyou:

Where are you disconecting the exhaust from to determin this? Catback? Y pipe? How are you testing? On the road without a Ypipe or any exhaust will make is slower off the line but will think your moving faster because of all the ground shaking noise and is not really a good test.

As said above the cats fall apart and clog themselves, also the mufflers and fall apart and do something similar, if its a dynocrap exhaust then the fiberglass packing can com apart and make a plug as well.

 

[94MTX3.2Swap]

Well from what my Brother was saying he disconected it from the motor its self. He was thinking it could have been a bad cat also so ill guess thats one of the first things ill have checked out. He was also thinking however that it could possibly be a bad injector? do you think this might also cause this problem? and we havent had it on the road to test it out fully yet still trying to work in the newer parts put on and also need to fill the tranny up with fluid. ill bring all this up with my brother tho and see what he thinks.

:thankyou:

 

[sho'noffmtx]

You could run a cylinder balance test but i would also lean toward the cats.

www.shophoenixproject.com

good luck

 

[sperold]

You are not going to be able to determine anything until you put it under load on the road. How high are higher RPM's?

 

[94MTX3.2Swap]

it was around 6-7k RPMs but we fixed the problem. well kinda stumbled on to it really. while he was checking the injectors he found one that wasnt seated properly and as soon as he put it back in correctly it ran like a top. but i think im still going to replace the cats here soon just to give it a llittle more breathing room. thanks for all the help tho.

 

[sperold]

I think if your problems were around 6 or 7000 RPM, you could probably live with them. Leave the cats alone unless you are sure there is something wrong with them. Treat them to a few thousand miles of a good running engine and they will reward you in return. The "equal to what you have" quality replacement cats are hugely expensive.

 

[94MTX3.2Swap]

i know but we already fixed the problem so i wont be doing it soon. its going to be a bit before i do it.

 

[sperold]

Sounds good. Over and out.

 

[94MTX3.2Swap]

ok a new problem has came up on us and we dont know what to do about it. the car is running like a top but for some reason it keeps wanting to over heat. we changed out the radiator and the thermostat but to no avail. they both needed replacing soo so we thought that was the only problem. but it still over heats. if anyone might have any info or anything we might be able to replace or try that might fix it please let me know.

:thankyou:

 

[93rev2sev]

Make sure the fans come on. Are you using ATX fans or the MTX fan?

 

[94MTX3.2Swap]

MTX. everything on the car is pretty much 3.0 stuff. just a couple things from the 3.2 were kept. pretty much just the injector system and the block are 3.2. everything else that we could get to work from the 3.0 is still on the car

 

[sperold]

Try another thermostat. If you have lots of time, try it without a thermostat at all. See what changes when you run it without one. It will probably take a long time to warm up at all, let alone overheat. Often I have to try 2 thermostats to get one that works. Go for new every time, no reuse allowed.

 

[94MTX3.2Swap]

we tried that one already but still it would over heat.

 

[sperold]

Leave the rad cap off and get it running. If there is a lot of activity in your rad and the liquid looks like Coca-Cola (froth and all), then your motor is injection super hot combustion products into your cooling system through your head gaskets. That is the worst case scenario. If there is no special activity in the rad, concentrate on your fan and whatever turns it on. Can these thermostats be installed upside down? Long shot.

 

[94MTX3.2Swap]

alright ill give that one a try and see what happens

 

[94MTX3.2Swap]

ohjust one quick question i didnt know were else to put this really but my friend is looking at a SHO. the only thing really wrong with it is the cat glows red when its running. im thinking its an injector because they changed that cats out and it still does it.

 

[sperold]

It is probably the injector. Liquid fuel is following the exhaust out and it is being burned in the cat.