Problems with 327 Z

[Guest Anonymous]

I just bought a '71 240Z with a 327 in it on Friday. It has Hooker Super Comp headers, Edelbrock intake manifold, Holley carb, Turbo 350 w/ shift kit, a Hurst Quarter Stick shifter, Accel Super Coil, and glasspacks for exhaust. As far as I know, it has stock internals. I only paid $2000 for it.

It does have some problems though. I have been in two races so far and each time it loses a lot of power when it gets into mid to high RPM's. It stutters a lot and slows way down. Any idea of what this could be? I have a new air filter that needs to be put in because the old one is bad. Also, one of the spark plug wires is pretty messed up on the distributor side. A lot of times it feels like I'm not running on all 8 cylinders. Before I bought it my Dad did a compression test on it and it came out fine. The problem almost always shows up at mid-high RPM's.

It also has a lot of electrical problems. One headlight is dimmer than the other. The car runs with the key in any position besides a point just before lock. The headlights and tach only come on when the key is in the off position. When the key is in the off position, the wiper switch will kill it. Any ideas on these problems?

Also, do you know any site that tells you exactly what year ypur engine is by the number on the block? i don't have it with me, I just know it is 393something. Also, how do you identify what kind of heads you have? On the part of the heads facing the front of the car, there is a pattern that tells you right? My heads have two humps on them.

Sorry about all the dumb questions, but I'm new to this domestic/carbureted engine thing. Thanks for your help.

[Mike C]

Start by fixing your electric problems. You could well be having ignition failure due to lack of electircal power. Next you'll need to check fuel delivery, but once again it may be electric if you have an electric fuel pump. Mortec.com has casting numbers which will give you a general idea what motor you have. Pull one of the valve covers and between some of the sturds you'll find the casting number for the head so it can be identified. Probably a 461 unless it has accessory holes in the ends in which case the 186 or 041 castings are the most commmon. Regardless, you've got a lot of work ahead of you tracking down electrical gremlins. Start by making sure you have good solid ground connections between the battery and the engine and then from the engine to the chassis.

[BLKMGK]

Pull the steering column cover and look for monkey business, I was pretty shocked when I saw th esplicing mine had endured. Higher wattage bulbs are often installed and since the juice goes right thorugh the headlight switch smoke often follows shortly afterwards. Relays, per the tech article here, will fix this and make the headlights MUCH brighter. Straighten up any other garbage you find in the column - it could be pretty bad.

 

Get the Jags That Run swap book. It'll tell you how it SHOULD be wired. It sounds like somone really fiddled around and didn't have guidance while wiring the car. Follow their directions and you may fix LOT'S of issues. Hrm, is the motor set back all the way with the distributor under the hood latch or is it further forward?

 

Lastly, find the sparkplug problem. If it's only missing a little at idle it'll miss worse higher up. as cylinder pressure rises the spark has to be hotter to jump the gap and spark. If there's something marginal anywhere that leaves a lower resistance path that's where the spark WILL go! Check the condition of the wires and all of the plugs, you may find the problem. If one plug is really dirty it may be the one misfiring too

 

Congrats on the puchase BTW, good buy! Post some pics please! It's always nice to see someone else's ride...

[Guest Anonymous]

I'd throw a tune up on it first, new wires, plugs, rotor and cap and adjust the timing to spec for a 327. Once thats been eliminated as a cause, then look at some other things. It doesn't sound like your ignition switch is in very good shape so that may/will need replacement. If you find to many problems with the electrical, it might well be wise to just rewire the car with like a Painless wiring harness.

 

Also, make sure the alternator is putting out 13.5-14 or so volts. I had a problem where the car was missing and down on power and it turned out to be the alternator (uhhh, figured it out when the car like didn't start or something.. ).

 

Just some idea's anyway. Good luck with it, sounds like a OK deal otherwise.

 

Regards,

 

Lone

[DavyZ]

Excellent advice from Lone, BLKMGK, and Mike C. Go for the full tune up like Lone suggested. Also make sure you replace that air AND fuel filter--sometimes a clogged or semi-clogged fuel filter lets the car run up to a certain point and then it starts to lose major power. Check or have someone else check the alternator BEFORE you just replace it. Same thing with the battery too.

 

As for wiring--if yuo find out it is a mess, a Painless system might be the way to go and will relieve all your electrical problems--shoot, if the car looks decent and has little/no rust you STOLE it! Investing $500 to $1000 to solve your problems is chump change. Take your time and buy the JTR manual like BLKMGK suggested.

 

Davy

[fl327]

for the stumble i would say look at the coil, and the cap, your points may be bent or off, or your dist. cap may be loose...

before you take off the column, i would suggest looking at how the wiring is connected to the fusible links, if connected to the wrong fuse, the lights and tach may come on funny like the problem youre having, and play around with it, but remember which ones you plugged in to where. also, a major tuneup is in order, change the hoses while youre at it and test the alternator that may be a cause for concern as well, thats for certain, and get a new battery while youre at it, check to see if both headlights are plugged in right, mine came loose and caused the dull light in one light, if compression is good in all eight and you said one wire is messed up, get a new set its part of the tuneup anyway, and get some good plugs, the double hump heads are the ones ,i have them on mines and i love em to death, camel hump headed old school hi-po !!!! that ignition issue with the key, sorry cant help you on that one....whoa. ok youre gonna have to make sure its wired up right, and open that column up, thats easy, matching colored wires for everything down there, love it.

ok try all that and tell us how you did!

[Two40MuscleZ]

Nick:

 

Try these three sites for SBC Casting Numbers and other gen. engine info:

 

1) http://home.twcny.rr.com/mcss/SBCinfo.html

 

2) http://www.mortec.com/castnum.htm

 

3) http://www.auto-ware.com/techref/castnum.htm

 

I concur with Lone and the other members about first giving your engine a general tune up. Check all elect.connections, dist. and wires. Also check the fuel filter(s), carb and jets.

 

Good luck,

 

 

Van

[Datsun660z]

Hi welcome to the forum

 

Any of the things the others have suggested may be your trouble. I know from my own

experience that if the electrical system lacks (voltage or current) good continuity to the coil it will idle just

fine but when you get on it, it will fall flat on its face. I just finished installing a SBC 406

in my 1976 280z (660z) and the wire that went to the coil was too small I ran that wire to

a relay that I added to the fire wall then a 12 gauge wire from the battery to the relay

from the relay to the coil and that cured my problems, so get your electrical figured out

and you just might have a car that will scare you.

 

Good luck Jon Peterson

 

[ August 08, 2001: Message edited by: Datsun660Z ]

[Guest Night_rider_383]

Nick.... The other guys said it right give her a good tune up 1st. Now with the top end miss i would bet your prod is that damn Accel Super Coil. Some folks have had good luck with them but 3 years ago i went through 3 of them sob's and none was worth a damn. My stock coil went out on my 350 in my camaro so we went to auto zone and picked up a super coil well the 1st had the high speed miss, took it back got another one. It worked good for about 20 min. and then it just died, took it back got another one and it had a mid and high rpm miss took it back and told them i just want my money. Called summit and ordered a msd coil and got it, put it on and aint never gived me a single prob. I used it 3 years on two diff engines under street and racing use.