out of the blue.. BAD missfire/hesitation & crazy tach signals

[keithrulz]

70' 1.9 opel gt
new spark plugs ignition coil wires etc.

I was taking a cruise yesterday like normal with no worries or problems and was on the road for about 45 minutes. Came to a stop light to find out when I go to take off i had some hesitation. well 15 minutes pass and it got much much worse.. almost no power.

It holds a perfect idle despite all this.. The only way it wanted to run was with the pedal to the metal or with very light throttle to hold speed, greatly limiting my top speed, I was probably doing 50 in a 60 all the way home. acceleration was near impossible unless I really put my foot in it. i can feel the intermittent bursts of power like it's trying to run correctly but just keeps tripping over itself. (unless i floor it then its fine) sounds like timing to me. but the distributor hadn't moved. and both advance and retard lines see no vaccum leak to and fro manifold and dist. i couldn't find a leak anywhere.

also at idle (1000 rpm) if i touch the gas to accelerate while out of gear the tach drops to about 700-600 rpm before it climbs past 1000 rpms all while hesitating and missing. KIND OF reminds me of when i don't have enough choke on a cold morning then tap the gas.

all input and ideas are welcome... i just fear that the problem will disappear by tomorrow like it did months back before the rebuild. nothing much more aggravating than trying to fix something that is no longer broken. .

[spamseptictank]

Perhaps the timing chain jumped a tooth?

[GTJIM]

Sounds like you are experiencing fuel starvation - it revs with no load but falls on its face when power (more fuel!) is required.

Check out the fuel sock in the tank - search for 'fuel sock'

Other than that you may have electrical gremlins - perhaps a bad coil.

DON'T drive it anymore till you fix the problem as fuel starvation will cause engine damage from lean mixture 'burning' the pistons with detonation.

'Caning' it will not solve the problem!!

Fix it .... now.

[neuropel]

When did you last do a tune up with new plugs/wires/ignition? Also, was it wet outside?

[MICAH1]

Have you checked to make sure the wires on your coil have a tight connection???

If you have the 32/36 weber, make sure the fuel strainer/filter (located under the fuel inlet) on the carb, not the in-line fuel filter, is clear and not clogged.

[dallasmanta]

If you are running points and condenser replace both. Sounds like the condenser is failing.

Most poor running issues in non electronic ignition cars is this component failure from past experience based on your description Remove fuel filter and blow the reverse direction to flow over a white paper towel to see how much crud/ sand/ water may blow back on to the paper. This will tell you if the fuel tank in tank filter needs to be removed and cleaned.
Ron

[stangslayer]

check for a cracked coil or carbon tracers around coil, check for good ground at coil. make sure plug wires are routed correctly and not arcing between each other

[Dan-MI]

Not to say it isn't fuel related, but I had this happen with a different type of car years ago. It'd idle and hold a speed but if you moved the gas (either letting off or stepping on it) it'd stumble badly and usually die. It ended up being the condenser.

[tekenaar]

Surprised noone has mentioned checking inside disti cap for carbon tracking, contact corrosion and/or moisture inside . . . moisture there will definitely! do this!

[ungermm]

My first guess would be a vacuum leak either at the intake manifold or at a vacuum hose. Hesitation or stumbling when you apply gas is a common symptom of a vacuum leak. Did you check the brake booster and hose?

As far as lack of fuel to the carb ... Although you might get an initial boost from the power pump, if you had a fuel starvation problem, I would expect that you would notice a loss of power at 50-60 mph while putting the pedal to the metal. However, if you were able to have prolonged acceleration after the stumbling or hesitation, then you were getting the additional fuel to the carb.
Jerry

[gt crazy]

my car did the same thing on bad days. my guess is electrical, just like my car.

[keithrulz]

Popped the distributor cap off and opened up the guts and the ground wire inside looked like it had a good connection, NO there were only 2 little strands of wire still connected! fixed that. (if this was the main problem im still puzzled on how the problem resolved itself months ago.)

also fixed the resistor for my msd coil. the substance the wire inside the rezistor was wound around had broken. and the helix was all bound up. I don't know if that had anything to do with my problem or not, but I bought a coil that didn't need external resistance.

I also checked the carb strainer (no i didn't know about this thing, awesome!) and it wasn't too bad but had collected some fine parts in it. one thing that concerned me was there was a small shred of rubber in it. assuming fuel line, i may be a sign to replace my fuel line.

Haven't changed the main inline filter or checked it since i put it on a few months ago, im heading to get a couple clear ones in a few moments, i like that idea! as for the in tank fuel sock I'll tackle that when I have more time.. and hopefully get my fuel level sender working in the process.

car runs great now.

[yellaopelgt]

Get 2 clear filters and put one A. right where the fuel line exits the tank.... Or B. right in front of the fuel pump. Either way, it will help you to figure out just how much junk is in your tank BEFORE it tears up your fuel pump!!
HTH Joe

[MICAH1]

Keith,
Glad to hear that you are running well again. I've placed a clear glass see-thru filter right before the weber, and have an in-line filter under the car prior to the electric fuel pump. That's two filters, plus the carb strainer before the fuel enters the intake.

[keithrulz]

thanks guys

I took out the old filter that was placed right before the fuel pump and put a clear filter in its place. i don't know how dirty if at all the steel filter was.. is there a way to check?

yes placed the other clear one right before the carb.

[GTJIM]

Glad to see you got on to it and cleaned up the problem(s)

You can cut the steel filter open with a hack saw to see what is inside - and that will make sure you are not tempted to use it again too.

[yellaopelgt]

Thats a really good question........I guess you could try putting down a white paper towel on concrete and just tapping it from the inlet side and see if any junk falls out??? I cant really think of any other way other than opening it up somehow...and then whats to decipher whats old junk and new junk? Maybe let it dry out for a while before you try this?? Just a thought....Regardless, you'll really like the clear filters,a small investment that is worth the piece of mind of being able to see whats going on with your fuel/tank!!!
P>S> You could also fill the filter with water...keeping the ends closed with your fingers, swishing it about,and dumping it into a coffee filter...

[keithrulz]

Well I'm pretty sure I found the culprit. might be surprising to you!

None of what I did before fixed it.. it reoccurred and not during the 200 mile drive to campus, but a short cruse around town after I got back a few days later. THANKFULLY not during the long drive!

While the car is idling and running poorly at a rpm higher than what the tach shows (but still idling less than what it should be idling at) I pull slightly on the top of distributor, toward me (drivers side) and the missing stopped, the tach read the correct idle, Idle jumped up, and it ran smoothly until i took the applied force off the distributor, then it ran poorly again and missed!

I figured i didn't have the clamp tight enough but it was very tight. when i loosened it all the way the car ran perfectly fine just like when i pulled the distributor toward me.

ive read in a previous thread that when the distributor was tightened the advance would retard maybe due to the cork gasket. well it is doing a similar thing but along with the missing crazy tach signals. and loss of power/undrivability.

I advanced the distributor beyond what i had it set at then tightened it down and it made no difference. it still missed sputtered backfired and the tach was bobbling everywhere.

what inside the dist. is doing this and why randomly? is it the dwell changing?

[MICAH1]

Kieth,
I think Otto may have been close to sometinng..... I take it that you are still running point& condenser??? If that is the case, I think now would be a great time to switch to the PERTRONIX system or new distributor!!!

[keithrulz]

you're right it is points and dist. That may be my only choice. I was hoping someone might know how to fix the distributor I have. I don't think holding it toward the drivers side with a bungee cord is a good permanent fix

i'll have do so some research on the pertronix for i don't know much about it.