Need help.

[Draven521]

So been getting my 71’ Datsun 521 updated. These week been focusing on my brake lines and suspension. The week prior I got the engine running again but to my surprise it would bog down and cut off when giving it gas. If I tap the pedal quick it would bog then backfire and rev really high. Now trying to start it again today it does not want to turn over. It cranks and then backfires. Sounds like a gun going off. A month ago I managed to get it running and finally got it to rev up with no issue. All I really did was disassemble my carb and clean it. Put it back on, it turned over just fine and was running just fine. Now where back to where we started and I can’t get it to turn over and stay on. I need help :,(

[datzenmike]

Check the points are clean on the contact surfaces. Gap when on the highest point on the distributor cam is 0.0198" to 0.022".

 

Inspect cap and rotor for cracks, wear or damage. Plug wires and nipples must be spotless. I wipe down with a rag and WD-40. This gives me an opportunity to closely examine them closely. Porcelain insulation on the plugs must be clean and undamaged. Inspect the top of the of coil for cracks and 'carbon tracking' which is where a spark has broken down the insulation and burned a path for the spark to travel from the center wire to the negative terminal. Looks like a crack or spider web. It may also be found on the rotor inside or outside the cap also. There is no really effective expiry date for ignition parts....  if it looks like shit... it IS. Check the points, coil and ballast wiring connections are clean and tight. 

 

 

[Draven521]

46 minutes ago, datzenmike said:

Check the points are clean on the contact surfaces. Gap when on the highest point on the distributor cam is 0.0198" to 0.022".

 

Inspect cap and rotor for cracks, wear or damage. Plug wires and nipples must be spotless. I wipe down with a rag and WD-40. This gives me an opportunity to closely examine them closely. Porcelain insulation on the plugs must be clean and undamaged. Inspect the top of the of coil for cracks and 'carbon tracking' which is where a spark has broken down the insulation and burned a path for the spark to travel from the center wire to the negative terminal. Looks like a crack or spider web. It may also be found on the rotor inside or outside the cap also. There is no really effective expiry date for ignition parts....  if it looks like shit... it IS. Check the points, coil and ballast wiring connections are clean and tight. 

 

 

Thank you for the reply Mike! All the ignition parts are new. The truck has not been on the road yet but has been on and running for maybe a total of 2hrs since I’ve taken over ownership. I did notice a lot of carbon build up on the spark plugs though. I don’t know what happened from last month to now. Every time I turn the key to turn it over it’ll just crank and let out a big pop (backfire). I don’t see anything else. The points are new! I did rebuild my entire dist because I lost spark this week but thankfully I have spark again

[datzenmike]

I guess I should ask: back through the carburetor or out the exhaust? They are often used interchangeably.

 

 

Out the intake can be a 'lean backfire' not enough gas. Bad vacuum leak, carb gasket or hose off the intake.

 

Too tight an intake may cause the valve to not close tightly and the firing cylinder can get past the valve seal and explode the air fuel in the intake.

 

Spark jumping to another wire

 

 

Out the exhaust is usually an interruption of the spark from the distributors. The raw gas and air is expelled into the exhaust and when the engine resumes firing, this explodes it.

 

 

 

 

[Draven521]

20 minutes ago, datzenmike said:

I guess I should ask: back through the carburetor or out the exhaust? They are often used interchangeably.

 

 

Out the intake can be a 'lean backfire' not enough gas. Bad vacuum leak, carb gasket or hose off the intake.

 

Too tight an intake may cause the valve to not close tightly and the firing cylinder can get past the valve seal and explode the air fuel in the intake.

 

Spark jumping to another wire

 

 

Out the exhaust is usually an interruption of the spark from the distributors. The raw gas and air is expelled into the exhaust and when the engine resumes firing, this explodes it.

 

 

 

 

Little bit of both to be completely honest. As of right now the issue is out the exhaust 

[datzenmike]

Well clean the plugs and while they are out crank it over holding the choke open to clear and dry everything.

[NC85ST]

Just my opinion, but it sounds like a timing issue. Try adjusting the distributor a little bit. May work, may not. 

[Draven521]

16 hours ago, datzenmike said:

Well clean the plugs and while they are out crank it over holding the choke open to clear and dry everything.

Mike I’ve checked just about everything. I still can’t figure out what’s wrong with my truck. Tried to start it again today and just a single loud backfire happens. It’ll crank until it back fires. Any other idea of what the issue may be?

[Stoffregen Motorsports]

It sounds like either the cam timing is off or the distributor is in 180 degrees out.

 

But if it ran before and you didn't change either of those things, it sounds like it could be elctrical.

[Draven521]

1 hour ago, Stoffregen Motorsports said:

It sounds like either the cam timing is off or the distributor is in 180 degrees out.

 

But if it ran before and you didn't change either of those things, it sounds like it could be elctrical.

I checked my marking for the timing and everything checked out. I’m assuming it may be the distributor. What do I have to do? What do you mean by 180 degrees out?

[datzenmike]

Was it running and then this happened??? If yes then the cam and ignition timing will be unchanged, perhaps a small ignition timing tweak but otherwise it's ok.

 

If you had everything apart and assembled it then it's possible some things were but in incorrectly.

 

 

So what's the story?

[Draven521]

1 hour ago, datzenmike said:

Was it running and then this happened??? If yes then the cam and ignition timing will be unchanged, perhaps a small ignition timing tweak but otherwise it's ok.

 

If you had everything apart and assembled it then it's possible some things were but in incorrectly.

 

 

So what's the story?

I figured out the problem. I think my dist is off just don’t know how much or how to getting back to where it’s supposed to be. I dropped the pump and rotated the gear just a little bit. Loosened the 10mm dist plate bolt and rotated it all the way to left and it turned over! It stays on for roughly 15-20 seconds then cuts off. If I try to give it gas it just bogs down. So im assuming I just have to drop the gear again and find the sweet spot, what do you think? 
 

I noticed where the rotor is pointing and it’s not centered on the contact point of the cap, it’s off a bit. 

[datzenmike]

 

Set precisely to TDC compression stroke on #1. Remove the distributor and look in the hole from the driver's side fender with radaiator to the left. This is what you should see.

 

Put distributor back in and the rotor should be near the #1 spark plug lead. NEAR the #1 because the timing is actually 12⁰ advanced. If installed properly this way the distributor is easily within adjustment range for setting the advance.

 

[NC85ST]

Timing issue. Make sure the shaft is set like Mike described and if it still has difficulty, have a second person try to crank it while you slowly twist the distributor, one way or the other, until it fires.  

[banzai510(hainz)]

if was running before how this timing change? only way 180deg out is soempne put the dist mount in 180 when puting the dist back in. the rorot will point in the same direction but the housing will be 180out thus rotating the dist cap.

you have  timing light? this will find it quick on how far it off it it soemwhat runs.

otherwise dial to TDC zero on crank. you can look thru the oil cap ans see where the lobe is at close to like 10oclock position then look at the dist rorot where it pointa dn should be close to #1 plug CCW fire order 1 3 4 2.

 

if idles then cuts out its oil pump off

main jet plugged

condensor bad

 

always make sure points gapped

[Stoffregen Motorsports]

On 1/15/2024 at 7:26 AM, banzai510(hainz) said:

if was running before how this timing change?

We never get the whole story.

[datzenmike]

... and often it's on the wrong track to start with.

[Draven521]

54 minutes ago, datzenmike said:

... and often it's on the wrong track to start with.

 

1 hour ago, Stoffregen Motorsports said:

We never get the whole story.

Story time. I bought my 1971 Datsun 521 in October of 2023. One night I was scrolling through Facebook market place and seen this beauty on there for only $1,000! Talked the guy down to 800 and had it dropped off. Mind you I only bought it because the body lines were decent and it didn’t look too rough. The man that owned it before had passed and his family just wanted to get rid of it. I was told it was running 3 years ago with no issues. Upon delivery I first made sure the engine could turn and that it wasn’t seized. Thankfully turned just fine! Next thing I did was check the tires. They were from 2002!! So I was definitely lied to. Upon inspecting the truck more I seen that the radiator hoses were fairly new as well as fuel lines so I’m assuming the previous owner was trying to get it up to par and his untimely death prevented anything further. I know I should’ve just bought a battery and see if it’ll turn over but I didn’t. Instead I bought everything to update the entire ignition system and did just that. For a while there I wasn’t getting spark and traced it back to a bad connection and it was good. The new starter I bought went out after a day of usage so I threw the old one back in and it holds up. Now when I replaced my distributor my dumbass did not know about engine timing because this is my first project. I didn’t pay attention to where my rotor was pointing when doing the switch over and I had trouble for the longest time to get it to run and finally did. It’ll back fire because of the that and I know that now. If it wasn’t for me watching Hainz video for a week straight over and overs again I wouldn’t have figured out where I went wrong. Yes it was running just fine once I figured out that my firing order was fucked but it would still cut off and bog if I gave it gas. Now comes the disassembling of my carb and cleaning the jets. Slapped it back on and it started over quicker and I was able to give it gas but even after giving it gas it’ll back fire out the carb and a flame would shoot out and then it’ll slowly bog down again (I believe it was too rich). Back to my distributor. Hainz helped me out before and said to loosen the 10mm bolt and rotate it left or right until the engine was idling at the right rpm and I did just that and got it to turn over perfectly fine but still coming across the issue of when I give it gas it cuts off (but I had good idle😎). I’m assuming it’s a clogged jet again because I am using regular gas when running it instead of non ethanol or without adding seafoam. That however doesn’t exclude the fact that my distributor is off if I’m having to rotate it so I believe that’s my issue. You all have confirmed that! So today is the day I drop the distributor pump and put it into the proper position. I will keep you guys updated with how that goes. 
 

the truck has also gotten updated brake lines and suspension! Dropped the tank when I first got the truck. Cleaned it and sealed it with a rubber tank sealant so I never have to worry about rust again. Pretty much everything is now up to date. I checked my timing Hainz. The lobes are in the 10 and 2 position just like your video says and my markings are lined up. Nothing is retarted or advanced. My point gaps are good and the condensor is new 

[Draven521]

1 hour ago, Stoffregen Motorsports said:

We never get the whole story.

I can give every detail If needed. 🫡

[datzenmike]

Unless the old owner said they were new tires what does 2002 tires have to do with anything?

 

Again set to TDC as mentioned, take the distributor out and look. If the oil pump was never out, the distributor will be timed properly to the #1 plug as per the picture I posted. You will have to loosen the timing adjustment screw and set the spark timing by twisting the distributor. Put distributor back in. It is impossible to put in wrong, it only goes in one way. Check the the rotor is pointing to the #1 plug wire. Firing order is 1342 in a counterclockwise direction.

 

Backfiring can be a lot of things not necessarily the distributor placement.

 

It won't backfire from being too rich, more likely from being too lean. Is your choke ON??? '71s had manual choke. Is the choke flap closed when the choke knob is pulled out. The choke forces a rich condition to help start and run a COLD engine.

 

When you have it running let idle 15 min till fully warmed up and the choke turned off. Now is the time to adjust the carburetor, not when cold or choke on.

 

Regular non ethanol gas is the same as ethanol gas for running. I've been running it for decades and the only result is a few % less power.... maybe.

[Stoffregen Motorsports]

1 hour ago, Draven521 said:

I can give every detail If needed. 🫡

We just never heard if it ran good and then it didn't, or if it ran and then you pulled the distributor and then it didn't.

[Draven521]

3 hours ago, datzenmike said:

Unless the old owner said they were new tires what does 2002 tires have to do with anything?

 

Again set to TDC as mentioned, take the distributor out and look. If the oil pump was never out, the distributor will be timed properly to the #1 plug as per the picture I posted. You will have to loosen the timing adjustment screw and set the spark timing by twisting the distributor. Put distributor back in. It is impossible to put in wrong, it only goes in one way. Check the the rotor is pointing to the #1 plug wire. Firing order is 1342 in a counterclockwise direction.

 

Backfiring can be a lot of things not necessarily the distributor placement.

 

It won't backfire from being too rich, more likely from being too lean. Is your choke ON??? '71s had manual choke. Is the choke flap closed when the choke knob is pulled out. The choke forces a rich condition to help start and run a COLD engine.

 

When you have it running let idle 15 min till fully warmed up and the choke turned off. Now is the time to adjust the carburetor, not when cold or choke on.

 

Regular non ethanol gas is the same as ethanol gas for running. I've been running it for decades and the only result is a few % less power.... maybe.

2002 tells me that it hadn’t been driven for quite some time. It’s illegal to drive on a tire thats more than 10 years old and is also a hazard so I highly doubt this thing was running 3 years ago. I’m assuming I’m undoing someone else’s mistake. I took off my dist it is indeed turned 180 degrees. The small side is on the right instead of the left. That’s from what the picture shows so I’m currently dropping it and getting it back in the right spot. 
 

my truck doesn’t have a manual choke. It’s an electric one. Thank you for the insight on the gas. Some random by stander at oriellys said I should’ve been running non ethanol lol

[datzenmike]

There are two TDC positions so take the valve cover off first and confirm that the front two cam lobes are not on either of the two rocker arms. Both valves should be closed and the front lobe pointing to about 2 o'clock and the second (intake) is at 10. I see no reason for anyone to take this apart and mess it up.

 

IF.... it does turn out that the distributor is 180 out simply change the distributor wires on the cap around to make it right. The rotor should be pointing to number 1 then in a counter clockwise direction it's 3 4 2

[Draven521]

On 1/16/2024 at 5:55 PM, datzenmike said:

There are two TDC positions so take the valve cover off first and confirm that the front two cam lobes are not on either of the two rocker arms. Both valves should be closed and the front lobe pointing to about 2 o'clock and the second (intake) is at 10. I see no reason for anyone to take this apart and mess it up.

 

IF.... it does turn out that the distributor is 180 out simply change the distributor wires on the cap around to make it right. The rotor should be pointing to number 1 then in a counter clockwise direction it's 3 4 2

Mike it’s me again. I thought I submitted a reply but I guess it didn’t go through. So upon further inspection I noticed that my rotor points to my 4th plug (4th cylinder). From my understanding of everything that I was told it should’ve been pointing to the 1st plug (if not close to it) is that correct? I was assuming cylinder 1 (plug 1) had to be fired off first so that’s where i think I’m confusing myself. If my rotor is pointing to the 4th plug (4th cylinder) is that the one that gets fired off first? TDC is set. Lobes are in the correct position. Dist pump is set according to the picture you showed me. 
 

when you guys say “should be pointing to the 1st plug do you mean 1st plug and cylinder or have I been misunderstanding that? 
 

I’ll be the 1st to admit I’m not the sharpest tool in the shed but I get the job done😭

[Draven521]

On 1/15/2024 at 9:26 AM, banzai510(hainz) said:

if was running before how this timing change? only way 180deg out is soempne put the dist mount in 180 when puting the dist back in. the rorot will point in the same direction but the housing will be 180out thus rotating the dist cap.

you have  timing light? this will find it quick on how far it off it it soemwhat runs.

otherwise dial to TDC zero on crank. you can look thru the oil cap ans see where the lobe is at close to like 10oclock position then look at the dist rorot where it pointa dn should be close to #1 plug CCW fire order 1 3 4 2.

 

if idles then cuts out its oil pump off

main jet plugged

condensor bad

 

always make sure points gapped

Can you shine some light on my recent reply to Mike just in case he doesn’t get to it in time. Just wanna get this truck on the road. I do have a timing light but for some reason I don’t any reading out of it. I think I bought a faulty one