1967 170 inline six hesitation and shake???

[TDubya]

When the 170 on my 69 started running poorly the four screws on top of the carburetor were loose and in fact one backed all the way out. Something easy to check.

 

[iSense67]

Has anyone done a fuel pressure or volume test, Before and after the fuel filter?

Generally the volume test will tell you alot and is free and easy to do using a little common sense.

Put a longer ethenol rated hose going to the pump.

They came from the factory with the black hard hose. Easy to disconnect on both ends and blow through.

Did you say how many fuel tanks it has /had?

It only has one fuel tank and the prior owner put in a new one I believe in the last year. Fuel pressure was not checked at this point.

 

[iSense67]

To

So, I have some questions and observations.

IN the third photo down from the top, what is the loose looking chunk of a part at the bottom of the photo?

The distributor timing advance works by rotation of the plate that holds the points. It needs to move freely by the vacuum diaphragm. You do not want anything rubbing, or restricting the movement. In the photo, it looks like the condenser wire is rubbing the inside of the distributor body? This could cause an intermittent grounding short, of restricted timing advance.

Make sure you test the distributor vacuum advance. Disconnect the vacuum line at the carb, rotate the distributor advance plate against the springs, place your thumb over the end of the line, and if the advance is working, has no vacuum leaks, the plate will stay advanced until you remove your thumb. It's a simple quick test, no gauges involved, and will let you eliminate that part as a possible issue.

Make sure your test the diaphragm in the carburetor "spark valve". It's the part on the side of your carb that looks like a power valve on a two barrel carb.

I would replace your points and condenser with quality part. I would look for NOS parts (Motorcraft) if possible.

John

I believe I figured out an answer to your question about that part in the bottom of the third photo as I found an online reference that it is a “distributor harness grommet.

 

[iSense67]

Update on my issue. Last weekend I replaced the kinked main fuel line and also replaced the condenser. The issue continues. That said I discovered on the carb that it is missing the vent rod in the carb which appears to help relieve fuel when it over heats. And in some cases people when rebuilding will either forget these or plug them. In my case the left it open so I ordered a new rod assembly. A I was looking over the carb I noticed a small hole above the valve spark control. I was thinking I could patch that with locktite gas and heat rated epoxy all said if any of you are carb experts I would be curious to your opinion of either of these two issues could be causing my issue? Also on the small hole do you think using an epoxy would help it or do anything?

 

[1970 Palmer]

The only thing the vent rod does is keep dirt out of the float bowel. It's more of an emission device sealing the float bowel. Good idea to replace/install it, but it will not have any effect on your problem.

It's hard to see for sure but it looks to me like that is just a drilled through and threaded hole from the above screw. Pulling the top off would confirm. No need to slobber epoxy on it, then the screw will be stuck. If it's leaking fuel or sucking vacuum while the engine is running it needs to be sealed up.

None of this will have an effect on your engine miss.

Have you checked the float level? Fuel pump pressure? Flow volume from the fuel pump? Compression? Is the compression low or uneven? Does this year model engine have solid lifters (require valve adjustment), or hydraulic lifters? What did the plugs look like, did any one cylinder have a black of fowled spark plug? Check the spark plug wires with an ohm meter.

 

[iSense67]

The only thing the vent rod does is keep dirt out of the float bowel. It's more of an emission device sealing the float bowel. Good idea to replace/install it, but it will not have any effect on your problem.

It's hard to see for sure but it looks to me like that is just a drilled through and threaded hole from the above screw. Pulling the top off would confirm. No need to slobber epoxy on it, then the screw will be stuck. If it's leaking fuel or sucking vacuum while the engine is running it needs to be sealed up.

None of this will have an effect on your engine miss.

Have you checked the float level? Fuel pump pressure? Flow volume from the fuel pump? Compression? Is the compression low or uneven? Does this year model engine have solid lifters (require valve adjustment), or hydraulic lifters? What did the plugs look like, did any one cylinder have a black of fowled spark plug? Check the spark plug wires with an ohm meter.

Thank you for your insights I haven’t checked the float level or volume from the pump but will have that looked at. The plugs did have some black on them but not horrible. Greatly appreciate your considerations I will focus on those areas this weekend!

 

[iSense67]

UPDATE:

I ended up using an electric fuel pump. It fixed the dying issue but now it’s running rough. I’ve brought this to 3 shops and it was running smooth before except the when it acted up. This latest issue is like a vibration and it barely gets up to 40 mph. The only thing I had the mechanic do was replace the points and he said the distributor was loose so he tightened it and checked the timing. When I picked it up it was running worse than before. So I took it to another shop and he added the fuel pump and checked the points gap and dwell but couldn’t figure out the problem. I’m in over $1000 and i can’t drive this bronco 5 miles without a problem. It’s very frustrating

In summary here is what has been done to it.

New plugs
New coil
New points and condenser
New pvc
New fuel line
New fuel filter
Rebuilt carburetor
New fuel pump
Checked for vacuum and everything was perfect

It starts up easily, idles fine. Note when you drive out it vibrates and isn’t smooth like it was before I started all of this so I solved one issue but all this work has created another. And as I said I’m on my 3 rd mechanic and none of them can figure this out. Any wisdom would be welcome.

 

[DirtDonk]

Don’t have anything concrete. But the unfortunate fact is that long list of parts adds an almost equally long list of possible suspects.
Especially new points and condenser‘s, if in fact the vibration is simply and how the engine runs.

Have you tried revving the engine in neutral and seeing if it still has an unnatural feel and does not want to rev up under load?
When you say it doesn’t want to go over 40 mph, what does it do? Does it simply run out of power and stop no matter how hard you press the pedal? Or does it just get so rough that you don’t wanna push it?

 

[BOBS 2 68S]

I know we are spending your money.
Check the fuel pressure, the electric pump might be to much for the needle and seat.
I replaced the pionts with Petronix system. Bolts right in. LMC truck list this, I also changed the coil with a Petronix unit.
Just remembered... my distributor cap would get a crack in it and when it rained here the Bronco would run like crap. Since you are in a humid aera maybe. I replaced the distributor no more cracked caps.

 

[TNcowboy]

I know we are spending your money.
Check the fuel pressure, the electric pump might be to much for the needle and seat.
I replaced the pionts with Petronix system. Bolts right in. LMC truck list this, I also changed the coil with a Petronix unit.
Just remembered... my distributor cap would get a crack in it and when it rained here the Bronco would run like crap. Since you are in a humid aera maybe. I replaced the distributor no more cracked caps.

Good point re the fuel pressure. I wound up putting a fuel regulator in.
The trouble I had was bucking on acceleration. Soaked the carb in chemdip and rebuilt....still had the issue. Tore it apart once more and used an ultrasonic cleaner, that did the trick. Couldn't believe how much crap came out of a "clean" carburetor

 

[iSense67]

Don’t have anything concrete. But the unfortunate fact is that long list of parts adds an almost equally long list of possible suspects.
Especially new points and condenser‘s, if in fact the vibration is simply and how the engine runs.

Have you tried revving the engine in neutral and seeing if it still has an unnatural feel and does not want to rev up under load?
When you say it doesn’t want to go over 40 mph, what does it do? Does it simply run out of power and stop no matter how hard you press the pedal? Or does it just gets so rough that you don’t wanna push it?

The last point it gets a little scary as itv accelerated so I didn’t want to push it. It really vibrates. Before it would shake and die die to not having fuel now with the electric pump it didn’t die but the vibration and running rough gets worse as it increases speed.

 

[gnpenning]

Double check your firing order. Quick easy and free. Also put a ohm meter on the wires.

Test everything, don't keep throwing parts at it. In the parts world these days new doesn't always mean good.

 

[Bajabrewer]

Bummer that you are still having issues. Are you sure it's the engine that's vibrating as you speed up? When you're driving & it's vibrating push in the clutch & coast - Still vibrating? could be an out of balance driveshaft, wheel or some other driveshaft issue. If it stops vibrating & coasts smooth I would look at the harmonic balancer. It may be close enough to balance to run smooth at idle but when it speeds up it will vibrate. I used Damper Dudes to rebuild a balancer for a 250 that I built & the turn around time was fast & it was around $100. I don't see a 170 listed on their Ford page but I'm sure they could rebuild the one from your engine. Good luck & keep trying you'll figure it out.

https://www.damperdudes.net/harmonic-balancers/ford/

 

[iSense67]

Double check your firing order. Quick easy and free. Also put a ohm meter on the wires.

Test everything, don't keep throwing parts at it. In the parts world these days new doesn't always mean good.

You nailed it I checked and the mechanic who just put in the points had two of the plugs wrong. I corrected it and now it’s running perfect!

 

[mrdrnac]

You should definitely connect that ground strap, it goes from the firewall to the engine. Not sure on a 6 cylinder where it attaches, maybe some one else will know for sure. Possibly to the back valve cover bolt, unless there is another easy to get to treaded location at the back driver side of the engine? Also definitely open the distributor and open the points and see if the contact surfaces are burned looking or pitted, if they are, just go ahead and replace the points and gap them correctly. Then reset the engine timing. I gave up on points years ago due to the constant maintenance required to keep them working correctly. Might be a good time to put a breaker-less electronic ignition in your distributor, it will run better!

Very sorry for my very late reply, I hadn't updated my computer and thought I was answering your questions while still on the first page of the thread, not used to the new format yet. Glad you are getting it fixed!

 

[66BlueGoose]

My 66's don't have a rear ground strap, probably added in 67. The only place for it to go on a 170 would be a valve cover bolt. Looked at your distributor pictures, its pretty dirty in there, I would recommend a rebuild at some point. Basically take it all apart, clean it and put it back together (parts if needed). That distributor also has an oiling port, it's the little hinged door underneath, you should periodically add some light oil. The rebuild on mine made a dramatic difference on the advance mechanism, it was much more responsive under load conditions. Out , rebuild and back in about 4 hours.

 

[Prest72]

UPDATE:

I ended up using an electric fuel pump. It fixed the dying issue but now it’s running rough. I’ve brought this to 3 shops and it was running smooth before except the when it acted up. This latest issue is like a vibration and it barely gets up to 40 mph. The only thing I had the mechanic do was replace the points and he said the distributor was loose so he tightened it and checked the timing. When I picked it up it was running worse than before. So I took it to another shop and he added the fuel pump and checked the points gap and dwell but couldn’t figure out the problem. I’m in over $1000 and i can’t drive this bronco 5 miles without a problem. It’s very frustrating

In summary here is what has been done to it.

New plugs
New coil
New points and condenser
New pvc
New fuel line
New fuel filter
Rebuilt carburetor
New fuel pump
Checked for vacuum and everything was perfect

It starts up easily, idles fine. Note when you drive out it vibrates and isn’t smooth like it was before I started all of this so I solved one issue but all this work has created another. And as I said I’m on my 3 rd mechanic and none of them can figure this out. Any wisdom would be welcome.

I have a 6 and am currently upgrading my distributor to a Duraspark 2 recurved by Bill (wsa111) over on the Ford Six forums. I would upgrade your entire ignition, if anything it will give may more power than you have now and we need all we can get in these 6's. 50/50 it takes care of the issue.