. I just swapped a motor into my car(87' N/A) and its not running too well. it idles fine, and actually drives fine unless I floor it, then it accelelerates bad and kind of "jumps". also, when its idleing, if I step on the car hard, it almost dies, then revs, but pretty slow. and it has NO power below 3000. I have to do mad clutch slippage(sp.) in order to not stall.

I'm thinking its either a fuel problem, AFM prob, or vacuum leak. am I on the right track? but I checked all the vac lines, and they're on good, maybe manifold gasket? ( the timing is perfect)

 

Go grab some carb cleaner and start spraying away. Have a friend rev the car while you do this. Performance will increase if you hit a vac leak.

 

Not saying your wrong or anything, but how come you rev the car up when you do it? I've always just done it at idle...if you hit a leak, the RMPS will increase...reving it while doing this would seem to make it much more difficult and defeat the purpose...

 

Some vacuum leaks won't even let you idle... but if you can, test it idling.

 

will doing this show me where the vac leak is? or just that it has one?

BTW, thanks.

 

If the idle goes up, you have a leak. The idle will go up when you spray a certain spot.... so your leak will be in that certain spot.

 

so I just spray all around the engine bay?

 

Welll... kinda, lol. No need to spray the coils, radiator, battery, etc, lol.
Concentrate on vacuum leaks, and gasket areas. You know, where vacuum of air is drawn?

 

he said his idle was solid...but yes..ive seen a vacc. leak (piston engine) that would not idle.

spray on engine...not on motor mounts..j/k.

Id conentrate around the manifolds...dont just give it one consisitent big huge spray..kinda do it in sections...so if idle climbs..you can pinpoint it...you dont have to drench it or anything..but you'll know when you hit it.

 

I'm not THAT stupid

thanks, I'll try this tomorrow when there's some light.

 

don't forget the TPS in your list of things to check

hugues -

 

okay, I think I found a leak

there's an area where I spray, a short 90 degree hose under the BAC thingy that goes into the upper manifold. when I spray where it connects to the manifold, the idle gets slightly smoother, and changes pitch. the RPMs don't really change(maybe a little).
so would this be a vac leak? I sprayed it about 5 times, and it did the same every time.

If this is a leak, should I just put a clamp on it? or what?

 

..

 

Sounds like a leak to me. Go buy some silicon vacuum hose and replace all visible and accessable vacuum lines. Rubber ones get hard from the heat and crack.

 

excellent I just hope this fixes the problem.

 

I tried new hose, drove around the block, same problem. got back, opened the hood, sprayed carb cleaner in that area, made the idle go up.
then I tried putting a clamp on the new hose...... same thing

could there be a leak in the actual manifold where that hose connects? I checked also for other vac leaks and found none.

 

ahhhh! I feel like such an idiot!!!

I went outside when my dad got home to show him the vacleak, and there was no more leak!!!!! but I started the car and it still ran like ***. then he started messing with the spark plug wires and I got really confused, so I pulled them off, and re-attached them correctly, and it ran good!!!! none of those bull$^%t problems anymore!!!! and it actually accelerated up the hill at 2000!!!!!!