Hello all

my name is JB. I'm new to this whole forum thing so bear with me. A little new to the high performance motor as well.

I recently bought a car purely for the motor. It's a 383 Stroker ran great for 2 weeks after I was finished working on it. Unfortunately the electric fan relay went out it got really hot started making some what I thought were ticking sounds. I figured out however it was exhaust manifold gasket had blown. Also noticed it was leaking a little coolant from around front intake bolt on passenger side. Replaced both exhaust and intake gaskets. Now it fires right up sounds great. No knocking no smoke no backfire but when you get it on the road and start to give it some gas it just dont jump anymore. It hesitates and sputters. It's got Pro Dart 1 heads, a Comp 212 cam, KB 111 pistons, a Weland team G highrise, Holly 770 street avenger, MSD street fire HEI, 2500 stall. I hope that's enough info about the motor. Getting frustrated with it and not sure what to try next looking for any advice sorry for the long post just wanted to make sure you knew as much as possible

. Thanks JB

 

Probably the ignition timing is about 20° or more retarded from where it wants to be.

Try advancing it and see what happens. Keep advancing it until it quits running better and starts running worse. "Better" and "worse" being some combination of peppy throttle response, max power, best gas mileage, cool running, easy starting, freedom from pinging, and so forth; according to what's important to YOU. Don't worry about "light" and "mark" and "number" and "spec"; instead of YOU thinking YOU're going to tell the engine what it's gonna get and it better like it, LISTEN TO THE ENGINE telling you what IT wants, and give it THAT instead. Remember always: "if it RUNS good, it IS good".

 

I agree. Needs more initial timing. Turn the distributor counter clockwise about a 1/4 inch and see if that improves it.

 

Thanks for the reply. I tried advancing the timing as suggested. It helped s little but still same issue. In park I can rev it up and all seems fine but soon as it's under load the is power loss when trying to accelerate. If I better it I can build up speed and get it going but obviously it's not right. I did notice however while I was doing that the vacuum was way low. I have a boost gauge on the car and it's only reading 4 to 5 psi at idle. About 10 when you give it gas. Checked all vacuum hoses. They were fine no leaks. I thinking maybe something went wrong with the intake gasket while I was installing it. It was a pain getting on. Just didnt seem to want to go on smooth. Hate to pull it all off again if that's not it but not sure what else it could be.

 

If it idles ok, I doubt the gasket is the issue. Keep advancing the timing until it cranks hard, eventually you'll get there a little at a time.

 

Advance the timing ALOT. Not just a little tweeeeeeeeeek.

 

so thinks for all the advice. This is where I'm at. I changed their take gasket for the second time. Sorry didnt see the post till after I had already done it. I have advanced the timing to the point I'm starting to run out of real estate. Lol. Now besides the idle being the same. Pretty much perfect maybe a little high. Everything else is just the opposite now. If I'm getting on it if runs great. Like a beast. When I even out to a cruze it starts to sputter and cut out. I wondering if I have fouled a plug or two.

 

Look at the rotor and make sure the tip thing isn't knocked off to the side.

 

Thanks like always everyone. I appreciate it. I'm trying everything you throw at me. Ok checked the distributor cap nothing knocked to the side out of place or anything can see. In fact that distributor is only 5 weeks or so old. So I fumbled with the timing a lot today got it where it runs pretty good most all the time except for that cruising between like 20 miles an hour up to 45mph if you're at a steady Pace it really really bugs out sputters bad anything higher than. 45 gets the RPMs up and it runs good again even at a steady 45mph with the RPMs up.
Something I was thinking about that happened the same time I don't know how it happened or what causes it or if it has anything to do with this but since then when I'm done driving and turn the key off the car doesn't stop running for almost a second doesn't seem like long but when I can pull the keys out of the ignition and start to reach for the handle before it cuts the power to it. Is kind of weird never did that before it's not dieseling it just literally doesn't cut the power to the motor for like a second. Got time to check my insurance policy for Accidental Fire coverage. Lol

 

Time to step back a second and reassess.
In as much as I appreciate setting the timing by ear at some point after fiddling and moving things around you have to get back to a baseline of some sort. You don't know if your initial timing is 8 degrees or 28 degrees at this point. An engine will run with either, some better than others with one of the the other. So, I suggest you put a timing light on it. Start with some known value and go from there.

I'm guessing the above refers to a vacuum gauge and inches of vacuum. 4-5" inches of idle vacuum is a problem. With that cam, installed properly, I'd be hoping to see 12-14" at a minimum. That's provided your static compression ratio isn't in the toilet.
Set the base timing to a known acceptable value, anywhere from 12 -20 degrees should be what the engine could use. While your at it, rev the engine and observe that the timing advances. It should keep advancing until past 3000 RPM. That value depends on what been built into your distributor's timing curve. All are somewhat unique and tune-able. Check the vacuum once you've baselined the timing. If it's low, try the old starter fluid trick (or similar) around the manifold base, carb base and vacuum connections. Watch for any changes in the idle speed. That might reveal something.
I'd hate to think that your overheating adventures caused any permanent damage but that could be. Check the plugs as you mentioned. The next step if nothing has been resolved is a compression test. That will reveal a lot about the state of the engine.

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Take some time to learn how to properly set ignition timing. Surely dont want to blow your motor up.

 

In order to "set the timing" using the mark and light, you have to (a) have an accurate timing mark, and (b) know what the "correct" timing should be.

You know NEITHER of those things. "Setting the timing" by using the light and mark is MOST LIKELY why your engine ran like crap in the first place... wherever you "set" it to, was NOT the optimum that THE ENGINE thought it should be.

"Set the timing" by adjusting it to where the engine runs right. Ignore all the rest of that.

 

Please dont just set the timing "wherever", or "it seems right". You absolutely should know how to use a timing light and use it. It is a great idea to get a piston stop and verify TDC, your timing tab, and balancer mark, to be absolutely accurate. Now will the motor like 34 or 37 degrees total, etc? Thats where some experimenting can come into play. I think its important that we give correct information. Do you have a timing light? Any experience using one? Surely dont want to see you set it at a ridiculously retarded position and blow the motor up cause "the motor thought it seemed happy there."

 

Seems to me the OP has been trying that and failing. He can't find that "sweet spot" the engine wants. He could be so far out (and the engines performance seems to indicate so) that he'll never find a correct setting. I'm suggesting he establishes some sort of starting point. Once there, he can dance with whatever method suits him. But as of right now, without the benefit of forty plus of experience, there's no determining where he's at.
And JB, I don't mean to cast any doubts on your mechanical skills, but it appear that it's time to step back to square one. Verify the timing. And your low vacuum.

 

Quite the contrary:

Sounds like most likely he used "light" and "mark" to set it to some "spec" he got out of "book", and now his car runs like crap.

"Light" and "mark" are of value IF AND ONLY IF (a) the mark is right, and (b) one already "knows" what THE ENGINE WANTS. "Spec", based on "book", is good ONLY for restoring a NEW car, with THE ORIGINAL MOTOR, back to factory settings; which in any case, IS NEVER the point at which THE ENGINE will be the happiest, even if it's still 100% original. The single highest priority for factory "spec" is EMISSIONS", which I seriously doubt the OP put a 383 in his car for the purpose of improving.

He has an engine that's completely different from whatever the "spec" in any "book" was created for. Plus, who knows whether "mark" is accurate. It is virtually 100% GUARANTEED that any "number" he comes up with will (a) NOT match his "mark", and (b) will NOT be what THE ENGINE wants.

Which is why the first thing he needs to do is put down "light" and "book", and ASK THE ENGINE what IT wants. NOT try to force-feed it something random that makes it run like crap.

"If it RUNS good, it IS good."

We call the process of extracting form THE ENGINE what its wants are, TUNING. That's what he needs to do. "Light" can be used AFTERWARDS to see what THE ENGINE WANTS, so that if need be, he can put it BACK to there. "Light" WILL NOT help him get the engine to run it's best. Only tuning can do that.

 

Perhaps the OP doesn't speak engine as fluently as you or I. In which case I recommend he gets a dictionary.
Now, that said, it was not suggested that he force feed something that makes it run like crap. Maybe, just maybe, the current setting is SOOOOOOOO far out to lunch that it'll never come back blindly. If it can established through some empirical measurements what the timing MIGHT be as suggested by a LIGHT and a MARK, then maybe, the OP can get somewhere. Again this is not to suggest that the timing is RIGHT or this is what the engine WANTS. But at least it'll give an indication of what the engine HAS.
Lesson one in troubleshooting. Establish your current position. Then go from there. But, you know that. You're just letting your experience get in the way .

 

"Light" is worthless in a situation like this.

For example: what if he has the stock crank damper, but a bolt-on timing pointer? Right there alone, "light" is going to be about 30 degrees OFF. Then, what if his damper ring has slipped, as most have?

What good does "light" do? He has no idea (nor do we) whether it's reliably accurate, and he doesn't know what the "ideal" setting even is. "Light" is WORTHLESS. Telling somebody to do that is not helpful, especially not if that's what got them to the point they're already at, as is likely the case.

He needs to determine WHAT THE ENGINE WANTS, not attempt to force some " number", however it is obtained, onto it.

Put down the light and start tuning. Then once "best" has been found, pick the light back up, see what it says, and write it down.

 

I wouldn't worry so much about the timing at this point. My concern is the very low vacuum at idle.
JB, you said you checked all the vacuum lines, but what about the power brake booster?

 

Grossly retarded ignition timing will cause overheating, low vacuum, greatly reduced power, and general runs-like-crap. IOW it's the simplest explanation that fits all the facts we have at hand. That's kind of how we got here... trying to get him to put down the light, which obviously isn't telling him the truth; and advance the timing until he finds the point where the engine likes it and wants it to be, independent of whatever number he comes up with using a light.

"If it RUNS good, it IS good". Conversely, if it RUNS bad, it's … NOT good. No matter what "light" says.

 

Sorry guys busy few days at work. No time for anything. Thanks for all the suggestions. Let me tell you where I'm at and stuff. I'm not a master mechanic by any means but I have worked on my fair share. I do have a timing light and I have put in on just to see if things lined up. TDC i found using a camera on compression stroke. Just waited till the shiny wall was covered by the piston. Thet matched o° to the 10°. Now I didnt build the motor so I can't be sure that it's correct but I believe it is. Now I have played with it for hours. All the issues are under load. So I can advance or retard timing 10° under idle and it seems to run good but a no point was I able to get back to how it was befor the overheating. Except once. That was 2 days ago. I decided maybe fouled plug bad wire. So I replaced plugs and wires just hoping maybe I get lucky. Did find a wire under brake booster that had got against the header and burnt a bit and cracked. Anyhow so replaced plugs and wires. Did nothing else at all. Fired it up ran good as usual so out for a test ride again. I made it about 20 yards befor it died. I was trying to turn around it ran the worst yet. Tried to start it again a couple times till the battery died. Pushed it back to the house put a charger on it. Waited about an hour had a neighbor come over to help me push it in the garage. Thought I'll try it again just so we dont have to push. Fired right up. Did a u turn really quick befor it might die and it lit up the tires and spun me clean around past the driveway. So I told him get in. Took a 20 min drive ran great. Parked it. Decided to go for a ride today got in could barley make it around the block. That's where I'm at. Yes vacume now is still about 10 at idle use to be a out 15+ I did do all vacuum lines but no not the booster and that could be part of it. The car does rev a little higher when I put my foot on the brake.
sorry this was such a long post just trying to get all the info out there. If I didn't answer anyone's question I apologize. Thanks for all the advi5 everyone.
. JB.

 

Acoupla things:

Post a pic of the dist rotor.

Is the vacuum can of the dist up against the right rear intake runner yet? if not, advance it some more (dist body CCW) and see what happens.

 

I forgot to mention: when you take the rotor pic, have the timing mark set to 0.

 

Normally in a situation like this you need to perform a complete diagnostic from the ground up.

1. Compression test. Use two different testers, one is always bad.
2. leakdown. Not necessary but if you can, do it.
3. Timing test. Use any means necessary to determine piston 1 TDC and mark the balancer. Then run the engine and do it again so make sure nothing moved. Finally set the idle timing to around 15-18* btdc and the full timing (using internal springs and weights I assume) to about 28-32* btdc if using 93 octane and less than 11:1 compression.

4. Crankcase and PCV pressure test. Pressure test the crankcase (only 1psi~ to 2psi MAXIMUM) to find all the leaks of the crankcase. Locate the PCV valve. make sure it has a pcv valve and that there is suction on it at idle. Find the freshair side of the pcv system also and inspect it for leaks, damage, blockages, etc... Replace as necessary

5. ignition and fuel system inspection. Do as before examine or replace all ignition parts including plugs and wires and rotor etc... If they look worn or fouled or damaged.
6. Finally you need a wideband to do the air/fuel ratio test. make sure it idles around 14.5:1 (carb'd? its fine even 14.0) and that at Wide Open Throttle you hit 12.0~12.5 is a fair range for 93 octane and less than 11:1 compression.

7. Also perform a cooling system pressure test IMO

Engines only need fuel air spark. If the spark system is good and setup right, and wideband shows good a/f ratio, the only thing left is air so air filter better be on it to protect the carb and make sure there are no crankcase (PCV) leaks and that the pcv system is intact and connected properly. The PCV system should pull a vacuum on the crankcase during Wide open throttle because it should be attached to the post-air filter tube (Like a factory vehicle). Examine factory service manual for almost any car to determine how this system should be setup and connect it properly for optimal performance and oil control.

Last you should not be trying to set the timing by ear or by magic. This is a huge mistake. That guy sofakingdom I used to think he was pretty smart but now I'm wondering if hes trying to **** you over on purpose or what. I don't think he is but the notion of setting timing (something done incrementally in terms of 1/16" at a time) is absurd IMO, I would NOT attempt that. One WOT run with a bit too much timing (42 instead of 36 for example) and you risk permanent engine damage. Not fun!

 

Honestly the first thing you need to do, for any engine, for any car, after an overheat situation, is a compression and cooling system pressure test. You have to rule out the bad head gasket and warped head theories before moving on to anything. I forgot to drive that home in the other post

And the more I think about it, sofa must either know you and not like you, or be jealous of you. Because 1/16" turn of a distributor can ruin your engine and he must know that by now. Every competent mechanic knows thats a risk you shouldn't take. Shame on that

On the other hand I maybe he just thinks you are hopeless and can't possibly learn how to properly time an engine. I doubt that is true, I believe you can do it

I've tuned 100 engines and before any of them went on a dyno it gets:
compression test
boost pressure and crankcase pressure test
timing test
Every. Single. Time.


A competent tuner should automatically know solid timing initial values for the majority of custom installation/configurations by simply imagining the process happening including stereochemistry of combustion shape/design (advancements in chamber technology) considerations, which is largely year based. So at some point it becomes safe for a good tuner to recommend values to himself and others most of the time, even for engines which he has never seen, You can get that way too if you practice and learn how.

 

I hope these help.

 

Ok that was a long check list. I will start with what I have the means to do st the moment. I know I'm going to get it about this... I did try to do compression test first thing. But the damn hooker headers make it impossible to get to them all without removing the headers. At the time I was really hoping not to have to take them off. So I could get tester screwed into 5 of them. All ranged between 125 and 145. At the time I was only looking for sings of damage ( Low compression ). So to just get and idea about the last 3 I did a simple thumb over the hole. I did a couple of the ones I had already done as a reference then did the last three. All felt like good compression to me. And there was never any signs of water in the oil. Or gas or anything in coolant. Mot to mention that after it overheated and I fixed the fans. The car still ran great perfect. It just had that awful knocking sound that was the exhaust leak. I replaced the exhaust manifold gasket and the car sounded great back to it's old self BUT I never drove it so I'm not sure. Cause as I was buttoning everything up was when I noticed coolant coming from around the 2 bolt from the front passenger side. So replaced intake gasket. That's what got me to here.

 

I would switch the vacuum advance line from the distributor, to the carb,... from ported to full manifold vacuum. Whens the last time you changed the fuel filter?

 

In as much as I've had excellent results using full manifold vacuum for the advance, I'd recommend against changing anything at this point.
Compression is a little low but I doubt that's the issue seeing, as you said, it ran well after the overheating.
Fuel filter inspection is a good idea. So is double checking the firing order at the distributor. It easy to inadvertently swap a couple of wires during a repair.
Still sounds like a timing issue though. (But check that fuel filter).
As suggested, try advancing the distributor until you run out of rotation room. Put a light on it then and post the results. Yes, the mark could be off, yes TDC could be incorrectly identified, but if the distributor was never removed at any time, the correct timing has to be in the installed range somewhere.
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HEI? do you havea full 12 volts going to it? Less than that can cause that exact same situation

 

I agree, put the vacuum line down to the baseplate to get full manifold vacuum at idle. That always seems to help part throttle response too

 

I’ve tuned 100s of cars myself and have found that many people’s timing tab for top-dead center were way off. Unless YOU degree/set top dead center and set the timing tab to read correctly, YOU can’t be sure if the timing tab pointer is correct. You can use a piston stop and degree wheel to set the pointer/tab but before going through all that, try this.

Loosen the distributor where it can barely be moved by hand. Have someone get in the car to crank and run it up to 3500 rpm and hold the throttle steady. Move the distributor up and down and the engine will increase and decrease in RPM. Move it to where the engine revs the highest and bring it down just a hair. This should be really close to what the engine wants (with the current distributor springs and weights). Bolt it down. If the car cranks easily with just a touch of the key, then you’re probably really close to where it needs to be. If no cranking issues, put a timing light on it to see what it reads at idle and at 3500. If it reads within reason the tab is probably OK or at the least OK enough. If it ran right before and there’s nothing else wrong except for the timing, this should at least get you back to where you were or possibly even better.

The start/no start when hot then cooling down sounds a lot like a bad coil or bad ground on the coil. Make sure the ground strap inside the cap (under the coil) is secured tightly. Sometimes the screw gets stripped and messes with the grounding factor.

 

Applying the brakes shouldn't cause a difference in idle. There's more than likely a problem with the brake booster. Could be the check valve, might want to remove that filter to rule it out.

 

So I'm workin on all these suggestions. Thanks again by the way.. Some info for everyone. The distributor has been taken out but since then I have ran it several times and have checked timing several times as well. Every time I find TDC it has been the same 10° lines up with the 0 mark. Not saying that is correct. It is consistent however. I advanced it as far as I could and that puts the 10° mark at well befor the start of timing mark plate. I'm guessing around 45°. I checked fuel filter but ther is no filter so I'll be picking one up today. Also checked volts at distributor cause car has had some electrical issues. It's pretty steady at 11.7 but thet seems a bit low to me. Working on checking more as time permits.

 

Interesting insight.
To follow that thinking, are the HEI ignition modules a go/no go kind of deal? I know heat kills them but will they fail intermittently? That may explain some of the OPs symptoms such as the sputtering and backfire.

 

Just wanted to clarify that when I said no fuel filter I was talking about a stock filter. Yes the is one on the carb. That is clean. Trying to find out about volts to distributor. Were I measured it was befor distributor. I would think that should be in the high 12's to low 13's when car is off depending on battery charge.

 

Can't be 45 degrees initial advance. You wouldn't be able to crank it. 12-15 degrees initial will be the place to start, with the vacuum hose unhooked. It may very well jump up to 30 degrees at idle with the hose hooked to manifold vacuum.

 

I think cuisinartvette means that there either might be a ballast resistor, or resistance wire built into the harness that is still in play. Great suggestion.

 

Any news?