Intermittent Problem with Betty's car, I am at my wit's end on this one. Options

[brant]

Tps

[MJHanna]

Time to drag out the carbs (IMG:style_emoticons/default/biggrin.gif)

[ClayPerrine]

My first thought would also be a electrical issue somewhere.

But you say you have no fuel sock, Have you ever had the tank lined?
I had an issue years ago where the liner came off in a sheet and would lay down right over the fuel outlet. Figured it would move off then get sucked back down after a few miles.

I had the tank out replacing the fuel pump. While I was doing that, the gas gauge quit working. I pulled the sender to both check in the tank for debris and to diagnose the gas gauge. The gauge was a broken wire, and the tank was clean inside.

Tps

L-Jet has a 3 position throttle switch. It has one set of contacts open at idle, and another set a WOT. It won't be a problem at cruise, and this can happen at steady state driving on a smooth road.

Time to drag out the carbs (IMG:style_emoticons/default/biggrin.gif)

With my wife, that will NEVER happen. Her car, her rules. She even got mad at me one time for putting a sticker on her car without her permission.



Thanks to everyone for their ideas. I am going to change both the ignition switch and the injectors next.

[EdwardBlume]

You changed the distributor, did you change the cap?

[partwerks]

I had an issue once with it cutting out, and randomly not starting after coming back from going shopping. It was a bolt that had been left too long, and after about 3 years of rubbing on a red wire to the map sensor, it would cut out. Shortened the bolt, and fixed the wire, and problem disappeared.

Might try to replicated the problem, as in wiggle wires, and such while it is running it that helps to dertermine anything??

[ClayPerrine]

You changed the distributor, did you change the cap?

Didn't change the cap, rotor or wires. But I can try that tonight.

[Drums66]

.....I had symtoms similar to those with a few 1.8's.......Check the *resistor
pack* & the wire's to the double relay.....peace (IMG:style_emoticons/default/idea.gif)

[fignewton]

probably not your problem, but one time with a 240Z, I dumped a bottle of carb cleaner in the tank just to realize as i tilted it that the cardboard stuff under the cap was still stuck to the long neck...just as it disappeared down the filler neck. Every time I'd get below a quarter tank, it would intermittently get sucked over the fuel pickup in the tank and the car would not get fuel. Sometimes it would just run badly; others it would run completely out (3 Webers). Had to pull the tank to finally solve the problem.

[7TPorsh]

Hmmm....mine was a pinched hose under the tank.

[ClayPerrine]

.....I had symtoms similar to those with a few 1.8's.......Check the *resistor
pack* & the wire's to the double relay.....peace (IMG:style_emoticons/default/idea.gif)

Resistor pack, injector harness and double relay have all been replaced.

[bulitt]

Clay- disconnect the fuel line at the tb and stick the line in a bottle then have Betty turn the ignition on for a second. You should get a good flow which will rule out clogged line, pump, filter, crap in the tank, vacuum lock.

[jim_hoyland]

Did you try grounding terminal III from the rear of the relay board ? This will eliminate the relay connection and wire- this test helped me the most.

Also, forgot this one; is the relay ground wire firmly attached ? I've knocked this loose when reaching in to clean the case.

[02loftsmoor]

I may have missed this in all the posts, isn't there a ground wire for the breaker point mounting plate?? I had that break on an MG, took a while to figure that out..

[ClayPerrine]

Clay- disconnect the fuel line at the tb and stick the line in a bottle then have Betty turn the ignition on for a second. You should get a good flow which will rule out clogged line, pump, filter, crap in the tank, vacuum lock.

Been over the whole fuel system. Replaced the pump, both fuel filters and all 4 injectors. Pulled the fuel sender and inspected inside the tank with a flashlight.

Did you try grounding terminal III from the rear of the relay board ? This will eliminate the relay connection and wire- this test helped me the most.

Also, forgot this one; is the relay ground wire firmly attached ? I've knocked this loose when reaching in to clean the case.

The relays on the relay board do nothing for the fuel injection on an L-Jet car. I checked the grounds under the intake 3 times now.

I may have missed this in all the posts, isn't there a ground wire for the breaker point mounting plate?? I had that break on an MG, took a while to figure that out..

I swapped out the distributor.


This morning I pulled the steering column apart and replaced the ignition switch. Tried to start the car and it wouldn't crank. Put the old switch back in and it would crank. The brand new in the box ignition switch is bad. I have to go buy a new one on Monday. So I hung the wires below the dash, and used a screwdriver to turn the electrical portion of the ignition switch. Drove it around the neighborhood beating and wiggling the switch and the wires. No correlation between that and the cutting out.



Update on what has been replaced:

1. Air flow meter
2. Complete L-Jet wiring harness.
3. ECU
4. Double relay.
5. Dropping resistors.
6. All 4 injectors.
7. Cylinder head temp sender.
8. Distributor, complete with pertronix unit (tried a set of points too).
9. Distributor cap and rotor.
10. Plug wires.
11. Fuel Pump
12. Front fuel filter in front of the pump (substitute for tank sock. The car doesn't have one any more and hasn't had one for years).
13. Rear fuel filter.
14. Opened tank and inspected the inside. Nothing visible inside.
15. Added dry gas to remove any possible water in the tank.


Trying right now to replace the ignition switch too.


(IMG:style_emoticons/default/headbang.gif) (IMG:style_emoticons/default/headbang.gif) (IMG:style_emoticons/default/headbang.gif) (IMG:style_emoticons/default/headbang.gif)

[JeffBowlsby]

Rather than throwing parts at it, the only clue is that is goes lean with every interruption. What could cause that?

Have you monitored fuel pressure and is it constant? You have replaced all the parts, but what if the fuel pump circuits are intermittent? Have you cleaned your grounds lately? The fuel pump ground on a 74 is under the relay plate. How clean do all the electrical contacts look? Tried DeOxit on every connection?

How about the coil, they can fail intermittently.

How about the spark plugs?

[DRPHIL914]

This thread is like a mirror image of mine, only it's d-jet not l-jet. But I also see mine going lean when it's cutting out intermittently.
My next step is plug wires,

[76-914]

Clay, I've read over this and have a question on some things I don't see. Does this happen at a certain power setting? Does the physical location have any effect? I assume your elev is constant in that area.This is reaching but I found this in an aircraft once. The fuel hose had a soft liner which had a torn spot that allowed this same liner to act as a flapper occasionally and almost always at WOT, read take off!

[ClayPerrine]

Ok.. I have determined what is causing it.

It's the alternator.

(IMG:style_emoticons/default/WTF.gif)

While I was out test driving it earlier, in my head I heard my father saying "What was the last thing you f***ed with?" My dad almost never used profanity, so when he did, it made an impression. I remembered that just before this started, I replaced the alternator with a fresh bosch rebuilt one. So I pulled over and disconnected the alternator wires from the relay board without turning the car off. Took off again, and it didn't cut out at all.

(IMG:style_emoticons/default/WTF.gif)

Stopped and hooked the alternator back up and it started to cut out again.

(IMG:style_emoticons/default/WTF.gif)


Tomorrow after work I am going to replace the alternator with one I just had rebuilt by a local re-builder. Then I will go through everything I messed with just to be sure nothing else is broken, messed up or otherwise out of whack.


I still don't know why the alternator would cause the injection to cut out. (IMG:style_emoticons/default/confused24.gif) Maybe some kind of voltage spike or blown diode sending reverse voltage to the ECU?

[mepstein]

Thanks dad. (IMG:style_emoticons/default/smilie_pokal.gif)

[ejm]

Since the problem is related to the charging system I would swap in another regulator before pulling the alternator. Why did you change the alternator to begin with?