LZ22 dying after fast idle (or sooner)

[71Hustler]

Hi everyone,

 

I wrote about this on FB Ratsun a couple weeks ago, thought I'd also ask here.

 

I have a 69 510 wagon with a LZ22 (bought this way, didn't build it) and a Weber 32/36 DVG. A few weeks ago, after starting strong and fast idling fine, it started gasping and dying when getting warm (when the temp needle starts moving). I think this video is public: https://www.facebook.com/kimberly.pendell/videos/10153993666923828/?l=765998126179561160

 

Once the engine was warm, it would still start strong, but quickly do the same (it's not dying quick, there's the few moments of painful attempts to keep itself going). In all of this, choked or not results in the same behavior once it's been running for a few moments. Stepping on the gas won't save it either. 

 

So, it seemed either fuel related or maybe electrical. However, after the following steps listed below, it's still dying, but even quicker (think it ran for about 40 seconds today even with a fully cold start -- granted it's 80 outside today).

 

I have, in this order:

-fed gas straight into the fuel pump from gas can to rule out tank/gas line/filter problem, no change in behavior

-checked for vacuum leaks with carb cleaner, couldn't find any

-replaced the condenser

-rebuilt the carburetor (returning idle and mixture screws to their earlier locations)

-double checked tightness on intake manifold, and carburetor adapter plate

-replaced the coil

 

Vacuum leak is still a possibility--my husband isn't entirely confident in his thoroughness, but we can't keep it running long enough at this point to look for them.

 

Any thoughts?

 

[datzenmike]

A case could be made for fuel or electrical. Lets narrow it down.

 

Electrical...

Get a timing light and connect the trigger to the coil lead. If the strobe flashes are continuous then not electrical from the points back to the ignition switch. Now try each plug wire. If there is an interruption of the flashes on any of the wires then the spark is jumping to ground somewhere between the distributor cap and the plug wire.

 

 

Fuel...

Next time it quits, take the top off the weber and see if there is gas in the float chamber.

 

If there is gas.... do you have an idle cut solenoid? Remove it and cover the hole with finger and try. If this works check the wire for looseness and/or make a temporary jumper from the battery 12 volt supply. If still not working the solenoid is bad. 

 

If no gas.... is the float set too high or stuck? Take the coil wire off so the engine won't start. Remove the fuel line from the carb and direct into a suitable container while someone uses the starter to turn the engine over. You should see sudden sharp gushes of fuel if the pump is working and the line is clear.

 

 

 

Need to know what it drives like? Does it act up while driving?

[banzai510(hainz)]

 No need to take the top off the carb to ck the float cahmber

Just cycle the linkage and see if the accell pump is pumping gas. If yes the chamber is full.

 

I think its a idle jet that is plugged on the weber

[71Hustler]

A case could be made for fuel or electrical. Lets narrow it down.

 

Electrical...

Get a timing light and connect the trigger to the coil lead. If the strobe flashes are continuous then not electrical from the points back to the ignition switch. Now try each plug wire. If there is an interruption of the flashes on any of the wires then the spark is jumping to ground somewhere between the distributor cap and the plug wire.

 

 

Fuel...

Next time it quits, take the top off the weber and see if there is gas in the float chamber.

 

If there is gas.... do you have an idle cut solenoid? Remove it and cover the hole with finger and try. If this works check the wire for looseness and/or make a temporary jumper from the battery 12 volt supply. If still not working the solenoid is bad. 

 

If no gas.... is the float set too high or stuck? Take the coil wire off so the engine won't start. Remove the fuel line from the carb and direct into a suitable container while someone uses the starter to turn the engine over. You should see sudden sharp gushes of fuel if the pump is working and the line is clear.

 

 

 

Need to know what it drives like? Does it act up while driving?

Thanks for the tips on electrical!

 

I don't have an idle cut solenoid. I'll check the float chamber next time. When it dies, there's often a burst of gas that shoots up from the carb (almost looks like smoke).

 

In terms of driving, we can't drive it...When this first started happening, my husband just got down the block and promptly turned around. It's been in the driveway since then.

[71Hustler]

 No need to take the top off the carb to ck the float cahmber

Just cycle the linkage and see if the accell pump is pumping gas. If yes the chamber is full.

 

I think its a idle jet that is plugged on the weber

Yep, plugged jet is the most popular suggestion. But I cleaned and rebuilt the carb--I feel pretty confident that the jets were clear and I got the float in the right place (brass float at 41mm).

edit:  also checked the float for leaks.

[banzai510(hainz)]

see you replaced the coil. You put a stock coil back in. Try running the old coil

 

Does the accel pump work on the carb. You should see gas squid in when you cycle the linkage. this should be able to keep the car running

 

cheak the idle jet anyways. But most likely its clean. 510 tank are usually clean. 521s are dirty cause the fuel line is in wheelwell.

[racerx]

When you say vacuum leak being a possibility did you spray carb cleaner around intake, carb plate, hoses? If there's vacuum leak, your RPM will go up and you can hear it.

 

When you installed the weber did you or your husband tightened it too much to the point that the carb plate got warped, which can cause a vacuum leak. Does it look like your carb is flooding, if so it could be the needle seat or housing.  Both of these happened to me and the car would run then die.  Good luck and keep us posted.  You can also OHM out the coil, not sure what the values are for yours.

[71Hustler]

When you say vacuum leak being a possibility did you spray carb cleaner around intake, carb plate, hoses? If there's vacuum leak, your RPM will go up and you can hear it.

 

When you installed the weber did you or your husband tightened it too much to the point that the carb plate got warped, which can cause a vacuum leak. Does it look like your carb is flooding, if so it could be the needle seat or housing.  Both of these happened to me and the car would run then die.  Good luck and keep us posted.  You can also OHM out the coil, not sure what the values are for yours.

Yes, carb cleaner was sprayed around the intake and carb plate. I'm not sure if my guy sprayed around the hoses, so that's still a possibility.

We couldn't find torque specs for the carb and adapter--I don't think he got too crazy with it. I replaced the fuel line from the pump to the carb as well cause it looked pretty old.

I'm waiting for a friend to help me with more troubleshooting, hopefully this weekend. *Fingers crossed*

[banzai510(hainz)]

there is a cheap carb adapter that can crack.

[Doctor510]

Yes, carb cleaner was sprayed around the intake and carb plate. I'm not sure if my guy sprayed around the hoses, so that's still a possibility.

We couldn't find torque specs for the carb and adapter--I don't think he got too crazy with it. I replaced the fuel line from the pump to the carb as well cause it looked pretty old.

I'm waiting for a friend to help me with more troubleshooting, hopefully this weekend. *Fingers crossed*

Check the fuel filter in the carb, it's under the 17mm brass nut under the fuel inlet fitting

[71Hustler]

Ok, so my fuel pump is definitely working fine, I have spark at the coil and plugs, and the coil read on the meter correctly. We also confirmed that the ground wire in the distributor is good (a suggestion as the possible problem from elsewhere).

 

All the actions I've taken so far have been to address this existing problem -- nothing's changed it. In terms of cracking or warping the carb adapter, the carb was removed and rebuilt to address this problem. If there was an existing crack in the carb adapter, I think we would have noticed it when reinstalling the carb.

 

It's dying even faster now, starting and turning over just a couple times. This seems pretty dramatic behavior for a vacuum leak, right? My friend suggested that something might be going on with the timing chain, so I guess that's another thing to check. I'm on the verge of having it towed into a shop, but dreading an expensive diagnosis.

[71Hustler]

Check the fuel filter in the carb, it's under the 17mm brass nut under the fuel inlet fitting

Yep, it's been checked at least three times in this whole ordeal.

[racerx]

Hard to tell if carb plate is warp unless u take it out and place it on a flat surface. U have a ballast resistor? May want to omh this out.

[racerx]

You can also run some comressed air to fuel line from line that feeds the carb, take off your gas cap, u should hear air coming out. One time this happened to me and not sure how silicon got in fuel line. My guess is previous owner siliconed gas sending unit housing and got into gas tank. Good luck and let us know what happened.

[71Hustler]

Hard to tell if carb plate is warp unless u take it out and place it on a flat surface. U have a ballast resistor? May want to omh this out.

Yes, there's a resistor for the coil. Sorry, but what does "omh this out" mean?

[71Hustler]

You can also run some comressed air to fuel line from line that feeds the carb, take off your gas cap, u should hear air coming out. One time this happened to me and not sure how silicon got in fuel line. My guess is previous owner siliconed gas sending unit housing and got into gas tank. Good luck and let us know what happened.

We ran gas straight into the pump from a gas can earlier to see if it was a problem in the tank or line, but engine still exhibited same problem. I replaced the line between the pump and the carb (it looked ok, but figured I might as well). Last night, we disconnected the line from the carb and ran it into a can, then ran the starter--gas flowed just fine from the pump and down out the line.

[71Hustler]

Hard to tell if carb plate is warp unless u take it out and place it on a flat surface. U have a ballast resistor? May want to omh this out.

Point taken, thanks--we'll check the plate for warping. Still surprised to think that this could cause such a massive failure.

[racerx]

If carb plate is warped, it causes a vacuum leak and car will start and then die. As far as ohming it out, you need a multimeter with ohm setting. You are basically testing for continuity or if there is a break in the wire. The ballast resistor, i could.be wrong is like 1.5 ohms it limits the current, hence resistor or resistance. I been in a similar times and i know it can be very frustrating. But this could also be fun because you will learn new things and how ohmeters works and how each indvidual part, whether or not it electrical or mechanical. Theres a lot of guys on this forum that knows their stuff, like doc510, datzenmike or hainz...if u dont have already get a multi meter and spark tester at harbor freight, very cheap and someone just downloaded tons of manuals on the General technical subject area that is very useful. In the meantime, make a list of the things that u have tried. Did you try running air in fuel line? Good luck.

[datzenmike]

I think more than enough questions have been asked about the adapter.... and answered. 

 

I can't see it being spark as it starts and then peters out. Electricity doesn't work that way.

 

But. As to the ballast resistor. Does it start while using the starter but quit as soon as you let go of the key? this could be the ignition switch or the ballast. A quick way to eliminate both is to jumper +12 volts onto the + coil terminal. Try starting it.

 

 

I think it's not getting fuel. I don't know webers but if the idle and primary barrel run on the same jet.. it's got blockage.

[71Hustler]

I think more than enough questions have been asked about the adapter.... and answered. 

 

I can't see it being spark as it starts and then peters out. Electricity doesn't work that way.

 

But. As to the ballast resistor. Does it start while using the starter but quit as soon as you let go of the key? this could be the ignition switch or the ballast. A quick way to eliminate both is to jumper +12 volts onto the + coil terminal. Try starting it.

 

 

I think it's not getting fuel. I don't know webers but if the idle and primary barrel run on the same jet.. it's got blockage.

 

In terms of the resistor, ignition, and ballast, it starts, and I can let go of the key. The engine dies a few turns in after start.

 

I did a compression test (cold, obviously) and got 150 +/- 1 across all four, so I was happy to rule out anything crazy going on there.

 

So, the plan at this time is to figure out how to check static timing, look more closely at the distributor, and circle back to the carb. It has to be fuel or timing related I think. A mechanic last year had adjusted the timing and carb to try to stop it from dieseling (unsuccessfully), but I wonder if that put it right on the edge of falling out of time. (Granted, I don't know if that's even possible)

[racerx]

to get more accurate compression check you should have the engine at operating temp.(hot), feel the upper rad hose (hot) or check your temp. gauge and then open your throttle all the way, then do a compression check.  I could be wrong but I don't think it's your timing because you say it starts then dies but it's good to see your initial timing. You can ohm out the ballast resistor, see my post earlier or jumper as what Datzenmike stated. You could also check to see if your carb is flooding and is so it could be the needle valve seat or housing.  Mine did that before and I opened up to top half of 32/36 weber and housing was cracked so it was letting gas in and flooding. 

[71Hustler]

to get more accurate compression check you should have the engine at operating temp.(hot), feel the upper rad hose (hot) or check your temp. gauge and then open your throttle all the way, then do a compression check.  I could be wrong but I don't think it's your timing because you say it starts then dies but it's good to see your initial timing. You can ohm out the ballast resistor, see my post earlier or jumper as what Datzenmike stated. You could also check to see if your carb is flooding and is so it could be the needle valve seat or housing.  Mine did that before and I opened up to top half of 32/36 weber and housing was cracked so it was letting gas in and flooding. 

I can't run the engine to do a hot compression test, thus the cold one.

[racerx]

Then you can't check initial timing. On the other hand, did you ohm out the Ballast Resistor?

[toylet]

Get some starting fluid and try to get the engine to run off the starting fluid.. If it does run, than this would indicate the fuel system has a problem.

[71Hustler]

Goddamn it! It was the points all along.