SC hesitates at 3-4000rpm

[gregg911]

When I accelerate up to between 3000-4000 rpm and hold the rpm steady, the car lurches slightly like it's not getting fuel or spark. The fuel pump, accumulator and filter is 5 years and 10,000 miles old. I'm thinking about changing the filter. My thinking is that there is some dirt in the filter stopping a steady pressure flow of fuel to the CIS.

Any thoughts or additional suggestions before I order a filter from Pelican?

On another related item, has anyone replaced the stock CD ignition unit with the MSD? If you did, what was the result?

[Trotskyite]

I have the exact same problem, but only when the engine is hot. I thought fuel filter too, but wouldn't it hesitate at any RPM? It also has had some trouble starting when warm, but fires right up cold. Power seems to be a bit down overall too, but that could just be me.

[Scott R]

Two things here, surging could be a lean condition. But start simple, how is your vacuum advance working? As far as the MSD goes, you're not going to notice much outside of the normal CDI, Bosch did a great job on it. That being said when mine went I replaced it with an MSD, only for cost reasons.

[gregg911]

Originally Posted by Scott R

Two things here, surging could be a lean condition. But start simple, how is your vacuum advance working? As far as the MSD goes, you're not going to notice much outside of the normal CDI, Bosch did a great job on it. That being said when mine went I replaced it with an MSD, only for cost reasons.

I'll check the advance. I was thinking along the same lines, if it wasn't the fuel, it may be vacuum.

I had a backfire a while back and blew the pop off right out of it's seal, epoxied it back in and thought I had it. Maybe there's a small crack or hose that's been damaged.

[gregg911]

I checked the vacuum line to the distributor, it looked good, hose was good, connections tight. Took the cap off the distributor and moved the rotor to make sure that it would advance, it all looked good.

Then I checked the inside of the airbox and with a flashlight noticed a 1" crack at the back of the box. Used a 5 minute 2 part epoxy and sealed the crack, let it dry overnight and drove the car this morning.

It runs great!!

[Gunter]

Alright, good fix.
Consider servicing the distributor anyway.
I posted an easy way to clean and lube, enjoy.

Distributor service (Clean and lube) real easy without removing the pinion gear!

[Fronnzy]

as for the possible vacuum issue, how is your idle, high? If it's high maybe check the route first as high idle is one indicator.