russ98stang

I just put an engine in with 70,000 on it and it ran great when it was pulled out. It runs great now but when i put a load on it it sound like a bunch of **** rattling or like a spark knock. I am running premium fuel so i dont know what could be causing this. anyone got any suggestions, i would greatly appreciate them.

russ98stang

o yeah, i forgot to ask. Do i need to retune it since i have the PI engine in a 98 car?
I went back with my original wiring harness with the NON COP's.

jvog

you should be tuned for your PI engine. The compression is different than an NPI engine that has had a PI swap

Frostbitten

the engine has different cams, compression ratio, intake, etc...sure its gonna run bad on a factory non pi tune...

wolverine8490

I swapped PI stuff onto my 96GT and did not get it tuned for months. I never had any strange noises. It actually ran pretty good without a tune.

As for what it could be, I'd say it could be a lot of things. Is it missing or does it just sound bad.

It is is missing, I would check for anti-freeze in the plugs holes, as well as make sure you have the firing order correct to start off with.

russ98stang

It just sounds like it is spark knocking when i put a load on it. I also forgot to mention that i havnt tapped for the second intake sensor. I cant seem to find the right tap for it. I've tried every where; parts houses, Norther Tool, Sears, Lowes. They all had the 3/8-16 NP. It says in the article that I need a 3/8-18 NPSF. But I do not think that sensor would make it sound like that, it just makes my fan run all the time.