Hey guys, another problem for me. Oh joy. I was driving home tonight from a friend's house, about 40 miles, and a little bit of the way home, car started sounding like it was a straight piped ls everytime I layed on the gas. I drove up yesterday no problems, drove around today no problems. Got home, let it idle, and it died in my driveway. It was hard to get off the line at lights, it didn't really like the gas. I check the plugs and I checked the carb, tore everything down, noticed one of the venturies was loose and tightened the set screw. Fiddled with the float and it started back up. Went for a drive and it still sounds the same. Weber 48 IDA. Streeport motor. MSD boxes.
Here's a vid. You can hear it better towards the end. It sounds much throatier. Any ideas??

 

Hole in the header or exhaust? Ignition miss?

 

Car runs and drives. Slight loss of power. It really doesn't like to be anywhere below 2,000rpms. And if it falls below that, it has to be nursed. Happened out of nowhere and I didn't hear a pop, and there was no indication of an instantly bad thing. It happened when it was running, I drive it everyday too. 9,000 miles on the rebuild.

 

I'm going to check ignition after school, I goofed yesterday and didn't bother checking ignition. I took a look at the rotor and cap, looks good.

 

May have lost a coil or igniter.

 

Would I still have the ignitor if I've got dual MSD boxes? I've never seen the little black box. Yet again I have no idea where to look, and all I'm finding is wiring diagrams when I search. How could I tell if I lost a blaster coil? Sorry, kind of a newbie.

 

Check your exhaust.

 

Headers are fine, no cracks. Besides, that wouldn't be causing the problem of not liking gas and not holding the idle it used to. It used to be a smooth 1,000 rpms.

 

I dont understand where else a "straight pipe exhaust sound" could be coming from.

 

Rotor 1. Top, then Lower plugs. Changed ~600 miles ago.





Rotor 2. Top then Lower plugs.

Saying it's a straight piped v8 was bad I guess. I meant to say it sounds much throatier. But it doesn't like to rev anymore. Anything under 2000 rpms and it wont have it.

 

Plugs look good, but i'd be checking compression to be safe since it doesn't want to idle below 2K

 

Compression is my worst nightmare. Engine was completely rebuilt 9000 miles ago. I dont have a compression tester. But I do hear 3 strong PSH noises. And if I dropped a seal, wouldn't it not run at all?

 

nah it can run on 1 rotor. Compression testers are 20 bucks at kragen.

 

Still running a cat? might be getting clogged

 

Why would a clogged cat make it louder? Lack of power and rank smell I can see but louder.. I'm not as certain.

Have you developed an Intake leak? Vacuum leak? (idle)

 

Clogged exhaust or vacuum leak. let it idle and spray starter fluid around the engine bay without starting a fire. If the idle changes, you have a vacuum leak.

 

Just did a compression test at my friends house....front rotor 80-80-80....rear is 0-0-0. Such is life. Anyone wtb? Lol

 

weird.

 

Still runs though. Which is why its so weird. Quite frankly it could be something else. But with no compression in the rear, it could even be a spun bearing, the needle did not move at all when I cranked it. Problem is, I'm not savvy enough for all this. Best to get rid of it before it sits in college.