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Fuel Injection Bobbing


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I removed the fuel injectors and soaked each one in injector cleaner for a day.   Just got it all back together.  Same issue.   Seems like a wicked miss.    changed plugs, wires, distributor cap and rotor, condenser and points.  No change.

 

Could the distributor be bad?   How can I check.

 

Can existing distributor be upgraded to electronic ignition or do I need to purchase a new distributor.

 

Any other ideas would be appreciated

 

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Did you try as Rob suggested- feeling each line for pulsing fuel, then pulling spark plug wires individually to see if one of them makes no change?  (Following this as I will soon be trying to resurrect a dead tii...)

Dave.

'76, totally stock. Completely.

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I pulled each plug wire while running and it had a negative impact on all 4... 

 

I will check the fuel lines this morning.   Forgot that piece.

 

I did notice that I am now getting a low POP, minimal backfire while the car is idling.

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If you soaked the entire injector together you didn't clean them enough.  You need to unscrew the top from the bottom and try to remove the pintle from the bottom portion. Tii's that have sat for a long time will turn the fuel into varnish and water. This will gum up/rust the pintle inside the injector.  

 

I also recommend removing the pressure maintenance valve on the outlet (fuel return) of the KF pump. That could be gummed up.  Be prepared to look for and replace the o ring on the PMV which strangely is NOT listed as a spare part.

Jim Gerock

 

Riviera 69 2002 built 5/30/69 "Oscar"

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3 hours ago, jgerock said:

You need to unscrew the top from the bottom and try to remove the pintle from the bottom portion. Tii's that have sat for a long time will turn the fuel into varnish and water. This will gum up/rust the pintle inside the injector.  

 

I also recommend removing the pressure maintenance valve on the outlet (fuel return) of the KF pump.

 

You are braver than I am Jim.  I gave my injectors, pressure valves, and pressure maintenance valve to a fuel injection service company for electro-static cleaning and testing.  They bench test each part, and although they can't do a "pulse" test on the injectors they can at least confirm spray pattern and burst pressure.  I had one pressure valve that was damaged and caused poor running.  Took forever to figure that out, until it was diagnosed by the shop.

73 Inka Tii #2762958

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5 hours ago, PaulTWinterton said:

 

You are braver than I am Jim.  I gave my injectors, pressure valves, and pressure maintenance valve to a fuel injection service company for electro-static cleaning and testing.  They bench test each part, and although they can't do a "pulse" test on the injectors they can at least confirm spray pattern and burst pressure.  I had one pressure valve that was damaged and caused poor running.  Took forever to figure that out, until it was diagnosed by the shop.

These cars are very simple.  I sometimes like a challenge when a car isn't performing correctly.  

 

IMG_6413.jpg

IMG_6410.jpg

Jim Gerock

 

Riviera 69 2002 built 5/30/69 "Oscar"

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i took the injector apart but did not take the Prindle out as I was afraid of it.   any trick in taking it out of the bottom half of the injector.   Do I pull it out or push it from the other side.   Don't want to break anything.

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Hovering up to 30,000 feet, the basic sequence I've used is:

 

--Cleaned the entire fuel system (described in a link on first page of this thread).

--Verified correct fuel pressure.

--Verified the absence of vacuum leaks with an inexpensive smoke tester (less than $75 these days on eBay).

--Verified that the warm-up regulator isn't corroded with old antifreeze, and sticking and not extending.

--Verified that the distributor is advancing, then set the timing (either using the ball at 2400 RPM or setting the total advance to 32 degrees using an advance timing light).

--Verified that there is spark at each cylinder, either by pulling off each plug wire, or putting a timing light on each plug wire.

--Fixed any slop in the linkage and set the system up according to http://www.2002tii.org/kb/59.

 

Generally the above steps -- hell, JUST THE FIRST STEP -- sort out most tiis so they run decently. MANY of these cars have massively contaminated fuel systems.

 

--If it's still running like shit, then I've looked at fuel delivery out of the pump to the injectors, which can be the pump or the injectors.

--This (http://www.2002tii.org/kb/59) is still the bible in terms of diagnosing bad suction valves, delivery valves, and injectors. Touching the injector lines with a finger is part of this.

--I have taken the injectors apart to see what's inside, and have found them obviously rust-contaminated, even one with a broken spring (see pics), but if they're clean, that doesn't guarantee they have a good spray pattern and aren't leaking. I haven't done with Jim has in terms of ultrasonically cleaning them. Like Paul Winterton, I've just taken them to a diesel shop for cleaning and testing.

--Installed an air-fuel gauge to get a handle on whether things are wildly lean or rich.

--Using the air-fuel gauge, adjusted the richness at wide-open throttle using the "verboten screw," and dialed in a compromise mixture for the rest of driving by adjusting the pinch point (where the cam covers the hole in the tuna can) and adjusted idle mixture using the tiny mixture screw.

--Only when there was no other explanation for massively lean running did I have an injection pump rebuilt. When I did, I later learned that the car had originally come from Santa Fe, and that, many years ago, the pump had been recalibrated for it to run in high altitides, which explained a lot. But, in general, I think you need to make a lawyer's case to rebuild an injection pump; I think that many people have them rebuilt needlessly. In my case, it was not truly necessary, and the performance improvement was modest at best.

 

 

rusty injector-1024.jpg

closeup #2 of broken injector-1024.jpg

The new book The Best Of The Hack Mechanic available at https://www.amazon.com/gp/product/0998950742, inscribed copies of all books available at www.robsiegel.com

1972 tii (Louie), 1973 2002 (Hampton), 1975 ti tribute (Bertha), 1972 Bavaria, 1973 3.0CSi, 1979 Euro 635CSi, 1999 Z3, 1999 M Coupe, 2003 530i sport, 1974 Lotus Europa Twin Cam Special (I know, I know...)

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Stupid question.   I took the pressure regulator valve on the return out and took it apart and cleaned.  How do I get the little horseshoe clip back in.   It sprung out twice and lost.   Half hour on hands and knees looking for it.

 

Bummer

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1 hour ago, buckweber said:

Stupid question.   I took the pressure regulator valve on the return out and took it apart and cleaned.  How do I get the little horseshoe clip back in.   It sprung out twice and lost.   Half hour on hands and knees looking for it.

 

Bummer

Confine yourself in a brightly lit room (like a small bathroom without any rugs). Close the toilet lid and sink stopper.  Using two small screwdrivers (pocket type), press the plunger in and jam the clip into place. It will usually pop out at least once.

Jim Gerock

 

Riviera 69 2002 built 5/30/69 "Oscar"

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23 hours ago, buckweber said:

i took the injector apart but did not take the Prindle out as I was afraid of it.   any trick in taking it out of the bottom half of the injector.   Do I pull it out or push it from the other side.   Don't want to break anything.

Soak the bottom assembly in Liquid Wrench for a few hours (or 24 hours if crusty). Place the bottom upside down between two pieces of wood then tap the pintle out using a round punch and hammer. Be careful if the injector is really rusty/crusty, as some can crumble the bottom portion if water has been left inside the injectors.  If you are queasy about doing this, take them to a diesel shop. Call before you go to make sure they will work on MFI equipment.

Jim Gerock

 

Riviera 69 2002 built 5/30/69 "Oscar"

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Thank you Jim,

Was able to reassemble the return pressure valve and put it back in.   Same worked for the inlet banjo.   Pulled the screen and cleaned it.   Put new plugs in although the other looked good.    I will put it all back together and then see if any change.   I will then pull the injectors and take them apart.

 

I did order McCatrney's 2002 restoration guide from Amazon.  Due to arrive on Thursday.

 

Thanks again to all.

 

Buck

 

 

 

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Cleaned the inlet Banjo and screen and the return pressure valve.   I threw plugs at it as well and put it all back together.   It runs 95% better.   There is slight hesitation in wrapping up but it runs pretty well now.  Far Far better.

 

Thanks to all for your help and patience.   Very Very happy that it is running better.  

 

Regards,

 

Buck

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