3100's got a cam!!!

[white4d96]

...okay, not really. But it sounds like it does

 

Thing is, only does it for like 3 seconds on startup, randomly. Then it'll surge a bit (like to 1200, nothing massive) for a minute then drop. Vac leak?

[Addicted to eaton]

Check for vac at the map.

[94 olds vert]

My car sounded like it had a cam. The rubber hose around the brake booster was shot. I replaced that and I went away.

[white4d96]

You replaced it and you went away?

 

:lol:

 

I do need to replace my rear breather tube? That plastic tube in the intake tube that IIRC goes to rear valve cover, mine's held together by electrical tape I'll replace the brake booster hose too, as I have next to no brake assist as well (which I actually kinda like )

[joecutlass]

I had the same issue and it turned out being the tps was bad.

[94 olds vert]

Yeah, I was mad my car didn't sound awesome anymore and I went away. Your problem could be a vacuum leak. Like you said if your breather tube patched by electrical tape.

[RobertISaar]

yes, fix breather tube, PCV problems can cause all kinds of weird idle things to happen.

[Garrett Powered]

I had the same thing. turns out the problem was the engine had a built cam in it. lol

[white4d96]

I had the same thing. turns out the problem was the engine had a built cam in it. lol

If only that was it.

 

Speaking of PCV issues, the elbow on my PCV going to the vacuum hose keeps collapsing. Replaced both PCV and elbow still does it.

[dodgethis]

If only that was it.

 

Speaking of PCV issues, the elbow on my PCV going to the vacuum hose keeps collapsing. Replaced both PCV and elbow still does it.

 

Are you saying that when you look at the pcv gromet thats the L shape that hooks to the plastic line that it expands and contracts? I was going to say i had the same situation with me when i did a tune up and ended up was given the wrong gromet. I think it was a dang spark plug boot that was an L shape. That thing didn't do the job whatsover. I was going to mention, try to head down to the autozone, or some auto parts store that sells, the "Help PCV fix" or something like that written on the box. It comes with the rubber gromet and and the plastic black line thats connected to it. I just took a knife and cut between the line and gromet, and used the gromet to fix the problem.

[dodgethis]

Are you saying that when you look at the pcv gromet thats the L shape that hooks to the plastic line that it expands and contracts? I was going to say i had the same situation with me when i did a tune up and ended up was given the wrong gromet. I think it was a dang spark plug boot that was an L shape. That thing didn't do the job whatsover. I was going to mention, try to head down to the autozone, or some auto parts store that sells, the "Help PCV fix" or something like that written on the box. It comes with the rubber gromet and and the plastic black line thats connected to it. I just took a knife and cut between the line and gromet, and used the gromet to fix the problem.

 

One other thing when my pos gromet would pop off the plastic line, and lost vaccum, man my 3100 would knock, stumble, sound like complete shit, until i fixed it.

[white4d96]

Okay, Doing some messing around and found something interesting:

 

If I pump my brakes with the car running, it will "lope" like it does on initial startup. So I'm thinking booster-ish area. I have heard the boosters are failure prone, but what else should I check first? Hose, check valve, ???

[spiderw31]

Okay, Doing some messing around and found something interesting:

 

If I pump my brakes with the car running, it will "lope" like it does on initial startup. So I'm thinking booster-ish area. I have heard the boosters are failure prone, but what else should I check first? Hose, check valve, ???

 

Disconnect the brake booster line from the plenum, and cap it off. You'll know for sure if the booster / check valve is causing the issue that way. Of course you'll have pretty terrible brakes, so don't drive it that way!

[white4d96]

Pulled booster hose and plugged it and she started up perfect, no issues. The check valve should just pop off right?

[spiderw31]

Yes, I believe it just pops off. If pulling the vac line off at the plenum did resolve the issue, I'm gonna say your booster probably has a slow leak. I'd also guess that if you pressed the brake pedal without starting your car after it has sat for a day results in a rock hard pedal.

[white4d96]

Surprisingly it's not that hard. Just for shits I backed down and up the drive with the hose plugged and it was firmer than normal, but still controllable. An emergency stop would be hairy, but that's about it.

 

But yes, if I leave the car sit the pedal firms up. As will it if I pump the pedal like 3 times with engine off.

 

If the booster is leaking I will just get a new 88-93 one (to clear clutch MC when I 282 it)

[spiderw31]

But yes, if I leave the car sit the pedal firms up. As will it if I pump the pedal like 3 times with engine off.

 

Yeah, that's probably a leaky booster then. Pumping the pedal with the car off depletes the vacuum "reservoir", but it should not deplete on its own that quickly. So what happens then is since the booster has no vacuum when you first start the car, it basically is a giant vacuum leak until it is replenished.