Hello everyone!!

I purchased a 73 Plymouth Scamp about a month ago and have been trying to keep up with any issues. It has 83,000 miles on it and looks to be fairly stock.

What I've done to it since I've got it:

I replaced reman holley 1920 carburator with a 72 holley 1920 from my no longer running 72. The reman started acting up and had to get rid of it for now.

Disengaged egr system and all applicable vacuum stuff, I was getting vacuum to egr valve at idle, making it run terribly, and with the older carb, I don't have the ports to connect it all anyhow.

Adjusted the valve lash, running hot to .010 intake, .020 exhaust, set the timing to top dead center, dialed in curb idle and idle air mixture at 750rpm. Replace fuel filter, did fuel line mod.

Installed oil pressure gauge, and replaced temp switch, and a few other things here and there.

Here are my current issues,

1. Idles rough as a cob, from initial cold start, and I have to pump the gas peddle about three times to get it to start. After it's warmed up it does better but still has something like a miss.

I did notice the intake/exhaust manifold is a little leaky(did the soapy water and got some bubbles) which may be causing the idle problem??

2. I was concerned when I did valve adjustment that I wasn't seeing a lot of oil flying around.There was oil but the white towel i put over the spark plugs had like ten small drops by the time I was done.

Maybe something plugged up, bad oil pump, or just how Slant six is???

3. I put in the oil pressure gauge to make sure I was getting pressure, jumped right up to 50. But I noticed on the drive to work today, when I got of the freeway it dropped to 20, and went up and down from there. Went back out after a couple hours started it up, jumped back to 50

Oil pump problem, Maybe just plugged up line(took gauge off the 72)??

I'm sure this car has been sitting in a garage a fair amount judging by the low mileage, and great condition(original paint, not an ounce of rust), so maybe stuff is gummed up, rotten seals, ???

Any how, thanks in advance for any help or direction!!!

You might want to service the oil pump bypass valve (pressure valve)

Richard

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Part of Tyrde-Browne Racing

Thanks I'll start there when I get home!!

Drained the oil , not positive but it seemed as though the oil was kind of thin, I was trying to smell for gasoline, but I can't really tell, seems like there may be some present, but not 100%. Is there another way to tell??,

tomorrow I'll change the oil, clean out the "bypass valve" and change the fuel pump...

Welcome on the board.

It will be a good idea to service the oil pressure relief valve to make sure it's doing its job, as described in these two threads: thread 1, thread 2.

Tune-up parts and technique suggestions in this thread.

Don't overlook the possibility that the carb you swapped on has problems of its own.

Manifold vacuum leaks will indeed screw up the idle.

A slant-6 in proper condition idles very smoothly.

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Too many people who were born on third base actually believe they've hit a triple.

I'm going to service the oil pressure relief valve right now

Just pick up an oil filter , I get the taller one right?

the parts store book was suggesting the shorter ones for 73 and later, for example 225, 1973 for STP it was a S16(little shorty), and for 72 it was SA8(much taller)

I always run the tall style such as a WIX 1806. I lost one motor to a brand new, bad oil filter provided by our local Valvoline Oil/Lube service center. Not fun.........nothing but the best from now on.......

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

Thanks Ted, I went ahead and grabbed the taller Bosch 3500.

Thanks Dan for the threads and Info.

I just about have everything back together,(waiting on a fuel pump).

Cleaned out the oil pressure relief valve, I had to blow it out from the top with a little compressed air, it was a little thick and sticky in there.

Did Notice a couple things possibly relating to idle while I was poking around,

1. Choke vacuum diaphragm was shot, replaced it with the '73 after it vacuum tested good.

2. I over looked disconnecting a vacuum line that goes from the Intake manifold #6 to the Vacuum Amplifier(?), I plugged it since all the other vacuum stuff is disabled.

I should know if we made some improvements in the next couple of hours!!

Ok, the oil pressure seems good now. 50 at cold start, once its warmed up after about 15 miles it goes to 25 at idle and back up to around 50 while driving, this sound about right??

Idle seems a little better when cold, but never quite gets rid of that "miss" one it's warm. Now and then, feel like there are little surges or losses in power while driving??

I'm looking at some Remflex gaskets to take care of the leaky intake/exhaust stuff so I can eliminate that from the equation, but I don't see any gasket for the "hot box", I'd like to just get a set to take care of the whole thing.

Has anyone ordered from them lately, do they have a package like that??

Miss at idle. Check your valve lash.

Gaskets: Check that the manifolds are true, and just pick up a set from your FAPS. I use Victor Reinz over the counter gaskets.
If you haven't already got it, search here for the torque and assembly sequence for putting the stack back on and together.
The fancy gaskets are great if you can't get the stack trued up. Shouldn't be any reason you can't. Assembled correctly, as long as the manifold surfaces are flat, the stack will seal on the least expensive gasket out there.


CJ

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Part of Tyrde-Browne Racing

Dave73,

The Remflex intake gasket comes with the hot box gasket. I believe the part# is 6008. Their hot box gasket seals the hot box area very well.

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

CJ just double checked and re-adjusted valves last night after a 15 mile drive, nice and hot, running. I really took my time and went too big and then to small just to see what effect it had on the rough idle situation, There was really no perceivable difference,...

so I put them all back to specs, still rough idle. I think I can rule out the valves.

I've replaced that whole group of gaskets a couple of time on my '72 with the stuff from the auto parts store, I would just like to try the remfelx, just makes sense to me, thicker more heat resistant... I've blown through 1 exhaust pipe gasket already on the '73 after only a couple of weeks of having it in.

Thanks for the info Ted I think I'll give them a call today and get that all squared away. If there is still a problem after that I can focus on carb and maybe electrical.

As a side note I really appreciate all the help everyone has been giving me, I'm probably at a sixth grade education level when it comes to this stuff so it's really great to have a resource like this!! I'm on overload with all the info I have been getting from this forum!! The more I learn the more I realize how little I know(ha, ha, ha)...

Anyone know a good place to to get a moderately priced engine service manual??

Also could a chewed up reluctor have such an effect on idle??(I have one on order from napa as well as a purge valve to reconnect the purge canister, should be here soon)

Sorry about the profuse posting...

I just remembered while readjusting the valves last night, I noticed again a lack of oil flow to the valves. I cleaned out the oil pump bypass valve the day before and just put it out of my mind. I wouldn't say the valve train was bone dry, but there was no oil splash when I raised the rpms, and I could not see any oil coming from any wherein any sort of substantial amount. I was tinkering around with the valve cover off and engine running for a good 20 to thirty min. with very little oil showing up!

I read S6Dans procedure for adjusting valves and from what was described, I believe I am not getting a good flow to the valve train.

So a blockage some where?? Can I put some compressed air in somewhere, clean out some other line some place??

Pull the rearmost bolt out of the rocker shaft and see how much goo is on the bolt. That is where the oil comes up to the rocker shaft and then to the rockers.

Richard

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Part of Tyrde-Browne Racing

Dave73,

Doc has posted some views of how the oil flows up through the block and head to the rear most rocker shaft bolt. Try cleaning the bolt up and see if it helps with the flow to the rockers. You may want to pull the whole shaft and soak it and the rockers. When you pull the bolts run some wire through the bolt holes and tie it off so you won't loose anything.

I also use a Remflex gasket on the head pipe joint to the manifold. They seal surfaces that are not in the best shape,,,,,,,I would try to clean/surface the flanges with a file or a board with a dark red 80 grit sanding belt first to help it seal.
I run a 2 1/4 flange and the Remflex part# is 6006.

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG