72 Tii Sputtering- After Warmed Up

[Ncbimma]

Update...

 

-Volts at battery at 2k rpm is 16.7

- Sprayed carb cleaner all over intake runners...no idle change

- Sprayed tunacan...nothing

- Need to check coil continuity- all plug wires are mostly new from bavauto

 

On the positive, I finally got the hazards and flashers to work properly... woohoo!

 

 

Edited July 28, 2017 by Ncbimma

[ray_]

Report back after you check fuel pressure.

 

I still suspect screen blockage at the tank. The screen there will collect tank crud during running so I'm not certain a test at idle will show the fault.

 

You allude that after the fault materializes, the car will run properly again. This again points to crap being sucked up at the tank screen, IMO.

[Ncbimma]

Good point. 

 

Never dealt with a gunked up tank before...any recs on a cleanse technique without pulling the tank? I assume just a siphon and scoop/sweep.

 

Best locale to T in a pressure guage- closer to tank or pre Kfish?

[ray_]

You can put the gauge at the cold start valve. 

 

If the tank is dirty, it's likely rust flaking off. If you determine that, pull it and get it coated.

 

GL,

[torquewrench80]

8 hours ago, Ncbimma said:

Update...

 

-Volts at battery at 2k rpm is 16.7

 

 

 

Are you certain of that voltage figure? 16.7? If that's correct your charging system is overcharging the battery, probably due to a malfunctioning voltage regulator. Leave it alone and you will ruin the battery by cooking it.

[2002#3]

Excellent suggestions.  

As others have stated, make sure your fuel pickup screen and unit do not look like this.  They should appear snow white (when new) and shiny silver, respectively.

Larry

Cincinnati, Ohio

[Ncbimma]

The volts we're checked with car off on battery at mid 12s. Then at idle, it read just about 13- fluctuating. Then at 2k rpm it sat around 16... Maybe I was at a higher rpm? I was using an extending brush handle to mash the accelerator- so might not be exactly 2k. I actually fried my voltimeter shortly after messing around with it and a 220 line in the garage...so I can recheck after I replace fuses..

 

Voltage regulator is brand new- I just replaced it think in it was causing the red dash light to flicker when the sputtering occurs.

 

My in tank screen is definitely not snow white. It's a rust brown in color but not gunked up. Something tells me the rust color is indicative of fragment obstruction...

Edited July 28, 2017 by Ncbimma

[Danz3]

I had similar issues when I first got my 74. I checked and chased the issue and finally pulled all the vacuum related hoses and replaced with new and verified that all were plumbed correctly. No issues since.

[Glen Karr]

I've learned a lot from reading Rob Siegel's (the Hack Mechanic) books and articles on the Tii's.  If you are still running the original electric fuel pump there is a cone filter in the inlet of the fuel pump.  When I changed out my fuel pump to the newer style I found that this filter was about 80% blocked with what looked like rust. It may be causing a fuel starvation problem on your Tii. When I installed the new electric fuel pump I installed a filter between the pump and the and the fuel pickup (NAPA 3299).  Also 16 volts is too high.  With car off it should be about mid 12's.  Running at any RPM the voltage should be mid 13's to 14 volts.  It would appear your new voltage regulator is not operating correctly.

Best

Glen

[gallian93]

I have to say...i still think you have some sort of vacuum leak...

Here are my assumption...

 

...You don't have an AFR meter on your car or you'd have mentioned it....

 

even if you had a bit low fuel pressure (say 20-25 psi rather than 29) it would matter more at higher RPM not at idle...but you said you looked at it...(if you don't have a pressure gauge, pull the return line to the fuel sender and run the pump..you're supposed to get a certain amount back in liters, that certain amount escapes me but you can look it up on the FAQ)

 

if you had spark issues you'd have a hard time get started.....

 

like you said in the beginning.... your car starts up fine and them after 20 mins starts to "sputter"...

 

I am thinking that during warm up the extra fuel from the WUR is helping with the additional air and then when the cone on the regulator extends (and shut off additional fuel) your tii is going lean and sputtering...have you noticed a change in your idle RPM?

 

I know you have said that you've sprayed carb cleaner over the runners... but there are plenty of other places that can give you a bad leak...

 

But before you go hunting for the leak... try this... cold start the car... and grab a flash light and look at your WUR.... i am pretty sure you are going to that as your cone rises and your additional fuel (thingy) screw hits or gets close to the stop you'll get the sputters...if that is the case get back to us and we'll track down that leak!!!

GL

 

Omer

 

EDIT... one additional thing i'll say is make sure the car is finished with the warm up sequence before carb cleaner hunting...it will help

Edited July 28, 2017 by gallian93

[torquewrench80]

5 hours ago, Ncbimma said:

The volts we're checked with car off on battery at mid 12s. Then at idle, it read just about 13- fluctuating. Then at 2k rpm it sat around 16... Maybe I was at a higher rpm? I was using an extending brush handle to mash the accelerator- so might not be exactly 2k. I actually fried my voltimeter shortly after messing around with it and a 220 line in the garage...so I can recheck after I replace fuses..

 

The actual speed isn't that critical, 1800 - 2200 is generally acceptable. Increasing the speed beyond that won't matter. Your max voltage should be 14.6, no matter how high you rev the engine. If it reads 14.7, maybe even 14.8, I wouldn't be too concerned. But.....anything over that means the voltage regulator is defective and in the case of 16.7 very possibly not functioning at all. The regulator is what controls the voltage output of the alternator. Many years ago I saw a vehicle with a complaint of no lights functioning. All the bulbs were burned out due to a defective voltage regulator. No joke. It makes me wonder what else on a vehicle excessive voltage might damage or cause. Personally, I'd stop looking at maybe/might/could be a fuel problem and correct the excessive voltage problem first, then I'd look to see how it ran afterwards, then I'd look to see if something might have been damaged due to the excessive voltage if there is still a problem. 

[kbmb02]

36 minutes ago, torquewrench80 said:

Personally, I'd stop looking at maybe/might/could be a fuel problem and correct the excessive voltage problem first, then I'd look to see how it ran afterwards, then I'd look to see if something might have been damaged due to the excessive voltage if there is still a problem. 

 

+1 - FYI, I've seen the readyily-available brand new voltage regulators fail within a week (and have replaced them with good, working used units from the stash). -KB

[Ncbimma]

Thanks all.

 

I will scoop up a new multimeter to verify. Maybe I fried mine messing around with it causing false/absurd readings.

 

I'm going to research what are all the vacuum connections and review/replace them.

 

Discovered today when I turn on my heater it fries something under the hood where it connects to the heater fan- something was smoking and popped my fuse...

 

[Ncbimma]

Just rechecked the voltage on the new regulator with a brand new multimeter set at 20v manual read:

Car off 12.5

Car on 13.6

Car at 2k 16-17

 

I tried testing the coil (Bosch 12v blue) set at 20 Omega and primary read 0.00 secondary read 8.3 ...this was with car off...I'm unsure if you power the car to test the coil.

 

I put back in the old volt regulator to see what happens.

And same battery results...on 2k the volt reads 17...

 

Bad alternator?

 

I crunk the car and I watched the warm-up regulator press a bit from the cold start and it settled back into it's resting place after 5 mins.

 

Idle speed was stable. I could blip the throttle easily and there was great response. I drove the car around the block 3 times spiritedly and got the early sputtering signs with the red light dimly glowing on dash and increased hesitation/ sputters. At idle car is stable- idle speed was slightly lower than at the cold start. 

 

When blipping throttle now, the car staggers to recover back to the start point and almost bigs out and the red dash light glows stronger.

 

Messed with WUR lever a bit and car begins to stall when any pressure is applied. Releasing and car returns to idle normally.

 

Sprayed all sorts of the bay with carb cleaner and found no areas that caused a reaction. All runner attachment points, all around valve cover way down where intake meets block...no reaction.

[ray_]

Well, the alt is putting out voltage. But it seems the regulator is not regulating. 

 

You may have a bad diode in the alt; that can cause the light to glow.

 

I'm wondering if excess voltage is causing the ignition to act wonky. But I don't think so.

 

I'm pretty sure you can pull the plug from the VR and take the alternator out the the circuit.

 

I suggest pulling that plug, checking with your meter to confirm the voltage when running is just battery voltage (12-ish), and seeing if the stumbling continues.

 

I still think it's a blocked screen, tho

 

Cheers,