Engine timing problems

[Jeepster]

I am still struggling to get my engine running and sort out the timing issue. I did tag onto the end of a previous post but thought I better start my own.

Some weeks back I had a fuel blockage which was traced to the tank sealer in the fuel tank coming free and blocking the feed pipe. So installed new tank and problem solved.

Then whilst on a 100 mile round trip drive the engine started to lose responsiveness and went very flat at mid revs. I managed to limp home and decided that it might be ignition related. I had planned to install new cap and leads etc so thought this a good place to start.

Installed new dis cap, rotor arm, coil, leads, plugs and electronic ignition module.

Since installing the elec ignition, I was told to expect that the engine would need re timing? When all the above was fitted the engine would barely run so I turned the distributor to try and improve tickover. This did improve slightly but the distributor has come to the end of its adjustment before I can advance/retard enough to even start on fine tuning the ignition.

How can I get the distributor to give more adjustment? It won't rotate any further clockwise at the moment.

There is a possibility that the original fault was a fuel blockage in the carbs from maybe some debris in the new tank? I am unable to investigate that until the engine runs.

I have. Fuel filter installed before the fuel pump.

Any help appreciated as I am at a dead end.

 

[Brinkerhoff]

If you've run out of adjustment you'll have to pull the distributor drive gear and reposition it . Refer to the shop manual .

 

[rjc157]

I would try going back to points and condenser and see what happens

 

[johnea]

I would check the carbs and the fuel delivery to the carbs before turning to the ignition.

 

[Jeepster]

I would check the carbs and the fuel delivery to the carbs before turning to the ignition.

If debris were to get into the carbs, where would it lodge?

With carbs I have worked on before, you can usually find the jets and give them a good clean or blow through with the airline to clean out any blockage.

 

[Jeepster]

If you've run out of adjustment you'll have to pull the distributor drive gear and reposition it . Refer to the shop manual .

I will look at the manual when I get home. Is this an easy operation or is it likey to throw everything way out?

 

[RAC68]

Hi Jeepster,

My first thoughts revolved around the possibility that some of the sealant may have gotten past the pickup tube and is still restricting fuel. Then, when you indicating difficulty in setting timing to compensate for the installed electronic ignition, I wondered if the module was seated in the distributor properly.

Sorry for asking some basic questions as I appreciate your Healey knowledge and experience. After eliminating the fuel blockage, did you validate the carburetors bowels are fully fueled and clean and the engine has returned to good performance before converting to electronic ignition? Since your timing adjustment seems to be insufficient, have you reviewed the installation of your new ignition wires follows the firing order and you are timing the engine by tapping off of the correct #1 spark plug wire? Again, are you sure the electronic module is seated in the distributor properly?

I understand these are things I would expect you have already have checked but I think an inadvertent and overlooked change is causing your problem. However, I would not make any major changes to the distributor unless, and until, you establish a reason for this major change.

Good luck, and all the best,
Ray (64BJ8P1)

 

[Jeepster]

Hi Jeepster,

My first thoughts revolved around the possibility that some of the sealant may have gotten past the pickup tube and is still restricting fuel. Then, when you indicating difficulty in setting timing to compensate for the installed electronic ignition, I wondered if the module was seated in the distributor properly.

Sorry for asking some basic questions as I appreciate your Healey knowledge and experience. After eliminating the fuel blockage, did you validate the carburetors bowels are fully fueled and clean and the engine has returned to good performance before converting to electronic ignition? Since your timing adjustment seems to be insufficient, have you reviewed the installation of your new ignition wires follows the firing order and you are timing the engine by tapping off of the correct #1 spark plug wire? Again, are you sure the electronic module is seated in the distributor properly?

I understand these are things I would expect you have already have checked but I think an inadvertent and overlooked change is causing your problem. However, I would not make any major changes to the distributor unless, and until, you establish a reason for this major change.

Good luck, and all the best,
Ray (64BJ8P1)

Ray,

your assistance is appreciated.

The fuel line always had a filter between the tank and pump and this looks clear, so hopefully nothing made its way any further down stream.

Following fitment of the new tank the car seemed to run fine for about 40 miles and the the problem slowly started to become more obvious.

The ignition module looks fine and the plugs are connected correctly. I have not yet been able to set the timing as I am waiting for my new strobe light to arrive and I am only just able to get the engine running enough to start that procedure ( due to the limited adjustment on the distributor).

 

[John Turney]

Each carb should have a screen on the fuel inlet. If those are clean, you should be getting good fuel flow.

 

[RAC68]

Yes, but did you check the carburetor bowls and, as John indicated, the screens leading to the bowls? I understand that finding blockage in the screens and bowls may have a low probability but fine dirt in the new tank or from the fuel lines could have formed deposits on the carburetor screens and in the bowls.

Quoting experience, as you may know, I commonly like to shift at high rpms (around 5K) and my engine usually revs without a misfire. About a week ago I took my Healey for a drive and, although still no misfire, the engine resisted getting to 4K rpms and occasionally backfired through the carburetor. Returning home, I checked the timing and the advance and both were dead on. Assuming my ignition was in good order (no mis), I decided to check and reset the carburetors (something I do only once a year). Pulling the bowl covers and checking the fuel line screens, I found some sediment on the screens and in the bowls. Resetting the carburetors after cleaning the bowls and screens, I went for another ride and found no more resistance to 4K rpms and easily passed 5K as well.

You do have a filter and looking clean is not always an indicator of being clean. There is still exposure from the pump to the carburetors and that may be where some sediment was disturbed.

Only a thought,
Ray (64BJ8P1)

 

[Jeepster]

Update -

managed to set the timing yesterday. Tried at the recommended 15 degrees and at various settings either side of that.

Car is still flat after over 2000 rpm. Starts and idles ok but doesnt want to run over 2000rpm. I also get the occasional popping and banging from the exhaust.

I have checked there is fuel to the carbs, float bowls full and clear of debris. ( I cant seem to find any screens on the fuel line inlet? fuel pipe goes straight into the float bowl)
New coil, plugs, leads, rotor arm, dis cap and electronic ignition.

This is starting to get frustrating, especially as here in the UK we have had glorious weather for the past few days and I am unable to enjoy the car.

 

[RAC68]

I understand your frustration.

When you set the timing with the vacuum advance disconnected, did you reconnect the vacuum advance and see how the timing responded when flipping and raising RPMs? I believe a stuck Advance (mechanical or vacuum) can cause some resistance to increasing RPMs and cause backfiring.

Good luck,
Ray (64BJ8P1)

 

[Jeepster]

I understand your frustration.

When you set the timing with the vacuum advance disconnected, did you reconnect the vacuum advance and see how the timing responded when flipping and raising RPMs? I believe a stuck Advance (mechanical or vacuum) can cause some resistance to increasing RPMs and cause backfiring.

Good luck,
Ray (64BJ8P1)

Just about to refit the points so will check the timing tomorrow and investigate your suggestion. I did wonder if the distributor was at fault?

 

[johnea]

The engine being flat above 2000 rpm might indicate a fuel issue: I'd try to disconnect the fuel line from the carbs and put the end in a jar and turn on the ignition. The capacity of the pump should easily fill a jar in seconds. If it trickles out you have a fuel problem . . .

 

[Jeepster]

The engine being flat above 2000 rpm might indicate a fuel issue: I'd try to disconnect the fuel line from the carbs and put the end in a jar and turn on the ignition. The capacity of the pump should easily fill a jar in seconds. If it trickles out you have a fuel problem . . .

Thanks. I tried that one and the pump fills my container no problem.

 

[Jeepster]

The engine being flat above 2000 rpm might indicate a fuel issue: I'd try to disconnect the fuel line from the carbs and put the end in a jar and turn on the ignition. The capacity of the pump should easily fill a jar in seconds. If it trickles out you have a fuel problem . . .

A fuel problem does seem likely.
Fuel feed to carbs is fine ( I have filled container as above post)
float bowls checked and both full with no debris.
I am unable to locate any fuel screens on the carbs ( I have HD8s and maybe this is not a feature on this carb)

is there anywhere else I can check on the carbs to look for debris or blockage? Ideally without taking the carbs off as I have no idea how you gain access to the lower inner carb to manifold bolts.

 

[John Turney]

I have fuel screens on my HD8s. They pop out when I remove the banjo bolts on top of the fuel bowls. From what I see, since the pump is working fine, the carb bowls are full and clean, I'm more inclined to think you may not be getting sufficient timing advance. Make sure the vacuum advance is connected and working, and the distributor weights are free to move and properly connected. Did you get that timing light? Does the timing advance when the engine is revved?

 

[Jeepster]

I have fuel screens on my HD8s. They pop out when I remove the banjo bolts on top of the fuel bowls. From what I see, since the pump is working fine, the carb bowls are full and clean, I'm more inclined to think you may not be getting sufficient timing advance. Make sure the vacuum advance is connected and working, and the distributor weights are free to move and properly connected. Did you get that timing light? Does the timing advance when the engine is revved?

John,
i am still waiting for my timing light to be delivered ( apparently its in the post) so I had my local garage look at it yesterday when the elec ignition module was fitted. He suggested I put the points back in so we could re check the timing tomorrow. I will report back.

 

[RAC68]

John, the same thing I had thought and suggested. Its always nice to find there is some validating consensus for a hypothetical suggestion.

I also have HD8s and, as John indicated, my screens are spring tensioned under each banjo fitting. Actually, I have not installed an in-line filter as these screens constitute my only protection against debris entering my carburetors (as original). Since you have an installed filter, I can't see how the lack of screens would affect anything.

All the best,
Ray (64BJ8P1)

 

[Keoke]

What gap do you have on the Plugs???

OH Yes you will need filter screens on the carbs but that is not relate to the present problem