RPM hang on 1.6 n/a CR engine

[sgnimj96]

       The engine started great and ran good but the rpms did hang some between shifts before I took the pump off to replace the big o-ring in head (It was leaking bad)...
     So here is some info:   After I got it back on (timed @ .88),  and I did try less and more advanced timings,  : it fires up like it should but doesn't want to idle right at first.       Cold start helps with the initial idle but after a minute it seems fine (it's not cold here in Florida today).    The thing is when i rev it up - the higher I go the longer it takes for the rpm's to come down,  up to 2 or 3 seconds.   A low rpm's it doesn't really hang.    I still haven't really rev'd it up because I know something is wrong.           The throttle is not sticking.   I took the springs off, cleaned them,  and also tried different settings with the smoke screw / idle screw.      Strangely,  less smoke screw did not help,  and a really low fuel screw / high idle setting make it worse.      So I took the smoke/fuel screw completely out to look at it and the was a ball of crud on the end of it which i sprayed off with brake cleaner.      Then,  thinking crud could be a big factor here,   I ran a can a diesel purge through the pump with some filtered hoses to a bottle.   The stuff looked clean running through the hoses but the bottle turned a faded color of 2-stroke oil (which I had used as a fuel additive previously).    Nevertheless,  this did not fix the hanging rpm's.     Other than that it drives fine.
       I'm wondering,  can take the governor out and clean it or does the whole pump have to come apart to get cleaned ?

[ORCoaster]

You should be able to top the top and see where the gob of stuff might have been on the lever that the fuel screw touches.  Or you might be able to swab it off through the fuel screw opening.  Just rembember to count the turns you need to remove it.  That way it is back to where you are presently and you can eliminate variables.

I would guess the gooey connection might be the problem.  You should be able to turn the fuel screw down enough to stop the hang and then bump the idle up if needed.  Open top may be the faster fix here if gooey as you say.

Christmas one day late for you? 

[sgnimj96]

         Thanks for the reply.     I wish had some christmas money now to have the pump cleaned and resealed - didn't realize it was that bad.      I just wanted to fix the leak.     An indicator was when I changed the head and coldstart o-rings, a lot of visible crud in those areas.   

[745 turbogreasel]

Pull the fuel  banjo  bolt off, an look in there, if it has significant  deposits,the pump internals do too.

It only takes the  thinnest  (and I mean microscopic) layer of polymerized alternative fuel goop on the control collar to keep it from moving right, but I don't think chemical Cleaning  alone will do much for that.
If your o rings are fresh, you should be able to  disassemble clean and reassemble the pump without  further expenditure.
Heat the copper washers till they begin to glow, let them cool, and they are good as new again.

[sgnimj96]

Pull the fuel  banjo  bolt off, an look in there, if it has significant  deposits,the pump internals do too.

It only takes the  thinnest  (and I mean microscopic) layer of polymerized alternative fuel goop on the control collar to keep it from moving right, but I don't think chemical Cleaning  alone will do much for that.
If your o rings are fresh, you should be able to  disassemble clean and reassemble the pump without  further expenditure.
Heat the copper washers till they begin to glow, let them cool, and they are good as new again.

I looked in the out banjo hole and it looks oddly clean but  there are some rust spots on the end of the governor linkage.       I do have a seal kit but never intended to disassemble the pump.        This was my first time to ever remove and install an IP.     
 

[745 turbogreasel]

Before you go too deep, unhook the whole cable thing, and verify you can still hang the RPMS.  If not, look close at motor mounts and cable.

[sgnimj96]

        After I installed the pump I ran it from outside the car actuating the throttle by hand.     A starter button switch and an alligator clip to the shutoff solenoid made it easy to get the fuel settings right.     But if it is the control collar,   does that mean full disassembly is the only way?       

 

[fatmobile]

 If there is enough crud it can keep the flyweights from moving like they are supposed to.
 Usually means the RPMs runaway don't just hang but that could be it.

 Did you get the accelerator arm on the right splines?

[745 turbogreasel]

You'd only have to take half the guts out, but if there is any goop or grit in there, I'd take the whole thing apart, and keep my expectations in check.

[sgnimj96]

      Thanks for the good info
  I opened the lid and the governor spring had some rust grit on it.   Hard to see because my camera doesn't focus well up close.
 
 I took it apart, cleaned it up the spring assembly, and ran the engine again.     Almost thought it was fixed (at lower rpm's) but no, it still hangs between shifts.      I guess the pump needs the full disassembly and cleaning...   

[damac]

Did you take the whole pump apart?

I can't explain why but I have brought back to life more than one pump that was undriveable on the car.  This is without me tampering with whatever setting were in place like the fuel screw.  I am no techie when it comes to the tuning of the pumps.  But I have seen gunk inside pumps still left over after using atf and diesel purge so to me the only way is a complete break down and cleaning, and then reseal.

I think I have been very lucky though, I have never seen actual rust on the inside of any of my pumps here in california, even those that I got dry.

Only experience I have had with a tampered fuel screw is, out too far and the car will not be able to move under its own weight on the road, even if you get the idle right on the driveway.  Too far in and that wierd hanging revs that acts like a cruise control cruising on flat roads around town.

[ORCoaster]

I was thinking the same. Complete teardown to get the layer of stuff off the control collar.  Only way to do that is break it down.  Solvents don't seem to get the layer off that is bound to the steel.

[sgnimj96]

     Yea I've tried to run good clean fuel since I got it,  but I've only had the vehicle for about 1500 miles.    Had to replace the tank because it kept sending rust up the lines, choking the fuel supply off.       
   It seemed like a healthy pump - no play in the main shaft,  clean on the outside  , until I opened up the lid...   
   Good thing I have another vehicle to drive while I work on it.     Now I'll get to see where all the rest of those seals go that are in the kit!

[damac]

Assuming you have never done it before its not really a big deal.  If scared there is a guy that sells a video on ebay that will prepare you.  That is what I did at the computer.  No big deal at all when you can take your time and prepare with vid and forums like this one.

Be prepared to possibly have to fabricate tools and I would suggest a vise to be your third hand.  Very nice security to know the pump body won't move at certain parts.  I admit once I dropped one on the carpet and parts went flying, possible if you do this you will not find them all so that part is no joke.  Some parts dealer long ago had told me not to mess with position of some parts like the rollers but I was forced to do so on that pump and it still worked   I don't even know if thats true but I don't mess with the order of parts anymore.

And even as a first timer, I could easily take pump off car, clean reseal pump, and have it back on the car in a day.

[sgnimj96]

           Thanks for the tips Damac,
     It wasn't something I was planning on but I do have some tools, space, and time.       I don't have the money to farm it out and the car is rather crusty MK1 so my options got quicky narrowed down to fix it right or ruin the pump by running it with crud inside of it.       Thanks to this great forum and the internet,  the info is all there -  I just have to be very careful because... well,  I know i've put things together wrong or backwards on several occasions  .     
      Fortunately,  I have tools, a small vice that I'll move inside and attach to a table, and can make stuff;  I'll take a lot of pictures,  and,  yesterday I bought the ebaydvd (after reading a thread from 2011        I will need to get puller or make something cuz I don't want to smack it with a hammer again removing it.
     
     I really like diesels (my other car is a 85' 300td)  so I'm fascinated by the process,   though I've never gone this deep.       Worse case I just have to send it out when I have the cash.           

     Check out this ridiculously simple tool I made to hold the sprockets while i tighten or loosen.     I cut the metal off an old hatch shock and bent it using a propane torch,   actuated with a piece of rebar.    Super crude but easy to make.