Issues After Intake Replacement On 96 Gt

[MysteryMachine]

I replaced the intake cause the stocker was cracked. Since then it sounds like a WRX. It runs like crap of course. I had the codes pulled and was told it's running lean. Pulling the fuel injector plugs one at a time doesn't really make much of a difference at all. 1 or 2 of them will make it sputter a little then go back to normal. I have checked the spark plug wire routing and that's fine. I haven't had a chance to pull the plugs and look at them. I really don't see what that's gonna tell me, if they ain't working it would be rich not lean. I have checked the injector connectors with a noid light and they all show fine. What else can I check on this stupid thing? I do have a tweecer R/T that I bought for my 94 but beings it's not being used I could hook it up if that will tell me anything. I would really like to get this thing running soon

 

[COramprat]

Could be some moisture in the plug wells. Pull the plugs and make sure they are dry.

 

[MysteryMachine]

This has been an issue for months now. I would think by now that would be dry, or am I wrong for thinking that?

 

[COramprat]

Not if it fouled the plug.

 

[sneaky98gt]

Sounds like an overall system problem to me. I'm thinking MAF sensor or coil packs.

Does it always run bad? Only at idle? Only under load? Etc.

 

[bhuff30]

Check carefully for vacuum leaks. Maybe you missed a vac. hose somewhere.
Also, not all plastic manifolds are the same. You used a npi intake for the 96-98 mustang? The 99-04 manifolds will bolt on (and give a nice bump in power), but there are a few tricks for sealing everything up since there is a little bit of mis-match.

 

[MysteryMachine]

umm at idle it doesn't seem too bad. You rev it and you can tell something isn't right. When driving it, it doesn't have the power it should.

The intake has the same ports as the stocker, my dad bought it for me off ebay. It was a birthday present. If I could find the link I would get it for ya. I do know that it had the gaskets built in which was odd. Only issue I had with the install was the rear bolt on the passenger side was really tight getting back in. Is there anything I can spray around to see if I do have a vac leak?

Can you pull the plug wires from the coil packs 1 at a time or is that a bad idea? I don't wanna get knocked on my ass lol

 

[bhuff30]

I think the dorman manifold has the gaskets built in, which is fine.

If you have a NPI manifold, the front most runner (closest to the radiator) will lead to the passenger side. On a PI intake, the front most runner would run to the drivers side. NPI is direct fit. If you didn't have any other issues with the install, you probably have the right one.

Just look for hoses that aren't connected, including the PVC, and any vacuum hoses you see.

From experience, yes, you'll shock yourself pulling a plug wire while the engine is running...

 

[MysteryMachine]

I was gonna do a PI swap but didn't wanna spend the money at the time so I went with a replacement. I did pull 1 plug wire last night and the snapping it made scared me a little LOL. My biggest fear is that the intake itself is leaking where that bolt gave me issues. I'll try and take a look tonight to make sure I got all the hoses and lines hooked up.

 

[COramprat]

A vacuum leak could be the problem but my experience it would idle crappy too. Is it missing? When the intake cracked it threw water all over. Likely in the plug wells too. Plugs are cheap. Replace them and see if it solves your issue.

 

[MysteryMachine]

I did have water in a couple wells when I changed the intake. I'll give that a shot.

 

[1fun281]

Sounds like you have a dorman intake manifold, i had one on my 99 and it sucked!! i swapped it out with a frpp pi intake and it was night and day difference, car had much more power, much more torque, was alot louder and just ran alot better!

 

[MysteryMachine]

Well spent the afternoon putting in new plugs. I did find a couple were full of water again while changing them. It looked wet around the intake which had me thinking the new one leaked as well. After getting everything back together I fired it up and it seemed to sound better. I reved it and it sounded good. Decided to take it for a quick ride down the road and as soon as I pulled out of the driveway it started sounding like crap and bucking. If I put any kinda load on it runs like . I have to keep it under 2k rpm and go slow. I left it running to warm up and checked the torque on the intake which all checked good. Tried to drive it again and still horrible. The heads dried up and I didn't notice any wetness after driving it.

I did notice a wire on the driver side all the way at the back of the fuel rail that's not connected to anything. I'm thinking it might be some type of grounding wire that connects to a bolt? It has an end on it like the plastic vac lines but it's a wire.

With all the bucking and missing I didn't get a CEL which surprised me

 

[Bob Hughes]

That snaps over a the stud closest to firewall on your fuel rails it grounds rails to engine/chassis as the o-rings insulate the rails from ground. That however wouldn't cause you're running issues

 

[COramprat]

Time to test the coils. When my radiator blew on my Expedition it spoiled a COP. Get a Haynes or Chiltons and it should tell you how to test the coil packs. If you need one let me know. I think I still have my stock ones off my old car you can have cheap. Heck I have two Haynes manuals. PM me if you need.

Did you check for vacuum leaks?