Help, Running Issues

For the last 4 months I've been working on this Cabrio project. After a lot of trial and error and replacement of parts I finally got to the point where I could start the car today.  I've just recently had my whole K-jet system rebuilt by KMI and it has now been bolted back on.  Unfortunately since bolting it back on suddenly the turn over is very lumpy and when starting its not sounding quite right, also from the smell from the exhaust its running very rich too.  Before having the injection system rebuilt it turned over perfectly but wouldn't fire due to fuel distributer being blocked but now very lumpy.

Please see attached video and any help would be greatly appreciated.

Thanks

I would start by checking the ignition timing, if it's too far advanced it could be igniting the fuel before the pistons are near top dead center and trying to push the piston back down the wrong way. Also check you have the firing order correct although it sounds like it's running on all four to me. Are you leaking fuel through the injectors when the engine isn't running? This would cause the cylinders to fill with fuel and increasing the compression, making it harder for the engine to turn over. Does your oil smell of petrol? What colour are your spark plugs? You need to remove the injectors and see if they're leaking fuel when the engine is stopped.

If it's been taken apart I guess they would of changed the mixture and if they did not bolt it back onto the car they would have no way of setting it up, first check the timing as above then the mixture is the last thing to adjust, you really need a CO gauge to do this properly you could ask a friend MOT garage if they could hook to up the ether machine if the car is road legal?

Just watched your video and the engine seems not to turn over fast enough upon crancking, how old is the battery and is it fully charged?
 

Yeah it needs tuning, as in:

1. Ignition timing
2. Mixture
3. Idle speed

and oviously other components such as those of the ignition system, should be in good condition too. Hesitation during starting can be due to too much ignition advance, but its normally just poor battery condition and/or wiring.

mark1gls said

Just watched your video and the engine seems not to turn over fast enough upon crancking, how old is the battery and is it fully charged?
 

I noticed that as well, mine sounded exactly like that when I adjusted the timing "by ear" and found I had advanced i way too much. It also did that when I had a couple of HT leads crossed. Either time though, it also ran rough whereas Mattrix07's engine sounds like it's running ok. I reckon the injectors are letting through when the engine has stopped and filling the cylinders.

So would that be due to the plunger not shutting when the engine is off?

Once you are sure that the timing is correct, pull all of the injectors and put them in a container. You will need to swap the fuel pump relay with one of the other relays (I can't remember which one it is, hopefully someone else can help) and when you turn on the ignition the fuel pump will run continually. You will also need to remove the duct between the air filter and the throttle body. With the fuel pump running you shouldn't have any fuel spraying from the injectors. If you do, turn the mixture screw anti-clockwise until they stop. You need a 3mm Allen key for that. Once you have done that, use a magnet to lift the plunger and see what the spray pattern is like. You should probably also check the quantity of fuel from each cylinder. I bought some baby bottles off eBay for £4 to do this. If you have a brown Haynes manual it explains it in there. If you've had the dreaded filler pipe rot you may need new injectors as well. If you read my post in the fuel system section (April 2016) you'll see what I had to go through. Good luck, keep us posted.

Thing is that's what I just spent £750 on to get right.  I had the fuel distributor reconditioned, the warm up regulator reconditioned, the cold start injector cleaned and serviced and 4 brand new injectors, fully rebuilt and sent back ready to bolt on. I wouldnt have thought the injection system would have been the issue but like I say before we bolted it all back on we tried starting the engine with brake cleaner into the air intake and it turnover, fired and idled perfectly.

Back to start first. Have you cleaned the fuel lines, fuel pump and accumulator, changed the filters and cleaned out the injector pipes? It sounds like you've sorted out the injection system but if there was rust and other rubbish in the fuel system it could have damaged all of the good work. Make sure that the timing is correct. If you don't know the history of the vehicle and its problems then it would pay to check the valve timing, ignition timing and all of the ignition components. Somebody might have played with these to try and compensate for the fuel issues it would have had from the fuel filler neck. As the fuel system has been reconditioned it is going to need setting up. You need to remove the injectors and make sure they're not letting through and if they are adjust the mixture screw until they don't. Then you can put it back together and start tweaking by ear! Good luck.

Anybody mentioned to check if there's contamination in the tank??? remove the rear seat & you see the black sender cover, remove this with care, the sender also, may get away with not moving this & you can see in your tank if there's debris in there from rust etc…

The smell is as you say running rich, get it tuned by someone who knows what they're doing (it's simple to get a 3mm allen key, do you trust yourself? - i've had issues with mine - in the engine block forum 'cold start splutter for 20-30 seconds' came down to the WUR (working fine electronically but the inside was leaking, seal had gone - serviced this myself, cleaned & got a new Viton rubber seal) & fuel pressure. Also the rotor arm was shot, replaced with Bosch Dist. Cap, Rotor arm & leads after this was done i got it tuned as it was smelling (had timing checked prior to my 'issues') Cleaned out Air system, Idle valve, took off hoses & cleaned through, FD, Air Meter sensor, had a service (last year) Made sure all the details were done so the Tune was the last thing, now responsive & good MPG. as Saulty said a Brown Haynes manual will be a good help.. (or the Bentley Manual - there's link on here to download it i think..)

Deandubya said

get it tuned by someone who knows what they're doing

^^^This (and I said similar in my earlier post
#1538523)

Setting mixture by smell, or indirect means such as revs dipping when set at the too-rich or too-lean stage, is at best a very rough technique for getting it into the right ballpark.

It needs to be set properly, using a gas analyser which can measure the CO.

It sat in the garage full of fuel for 29 years so as you can imagine it was disgusting, almost like treacle, it had contaminated the whole injection system so have got rid of pretty much all the old fuel system. Its had a brand new tank put on, new sender unit, new fuel pump, changed all the hoses around pump, accumulator etc, new fuel filter, reconditioned fuel distributer, reconditioned, warm up regulator, new injectiors, service and clean of the rest of the system.  Engine has also had full service and all plugs and leads checked, new battery, new relay and this brought me up to point in the video.  As mentioned it was started from brake cleaner before I was able to get fuel to the engine to check how strong it was and it turned over, started and sat very well.

Any Kjet experts in the Elmbridge area that might fancy a look for me, very frustrated!!!!!

Did you try any of the things that were suggested?