TheSamba.com :: View topic - Engine has a dead spot when reving engine. Idles fine.

Sun Sep 20, 2009 7:22 pm

I need a little help here. I have 1600 DP with SVDA with vac. line attached and timed accordingly and as of late the engine has a dead spot on acceleration. Unlike 009 flat spot issue with the pict 34, this is different. Here is the breakdown:

1. Engine takes a quite a few cranks to get started as if starving for fuel in the carb bowl.
2. Idles great.
3. Timing, valves, adjustment to carb done.
4. Noticed a lot of condensation building up around carb base and adjustment screw area. Condensation tends to drip down the intake manifold a little. Very humid in Miami.
5. Revs with no hesitation, but then at around 2500 or so complete dead spot as if the I lost spark for a split second. I can push past it by giving it more gas and it revs out fine.
6. Plugs and wires are new as well as cap and rotor. All Bosch components.

Now, I have resealed the carb. and blew out all jets and passages, although it was a new Mofoco purchase. No issues were found.

I did notice the fuel filter looking quite empty when running. Should some residual gas be able to be seen as it is refilling from the pump? When the engine is shut off there is around 1/2 the filter full of fuel.

Maybe I am not getting the right amount of fuel from the tank or the screen is dirty.

What gives? Help!!

Mon Sep 21, 2009 5:37 am

I install the filter before the pump then check to see if the gas shoots across the driveway :lol: you'll know if the pump is working :shock:

Mon Sep 21, 2009 5:44 am

One thing to consider is, does your gas tank have a way to bring in air when the gas is sucked into the engine. If not, it could create a vacuum that will cause the fuel pump to not perform effectively at certain RPM's.

Mon Sep 21, 2009 6:22 pm

I have a vented cap, but I have thought about this before. Wouldn't the car basically die out if it was starving for fuel after the dead spot threshold is reached? Once I get past this dead spot, it revs out with no problem. Could a bad condenser cause this? It doesn't happen at the same RPM it seems.