Back fires, not starting D-jet?

[vwbill]

Hey, all I can get the motor to do is back fire? It pops pretty bad too!
I read through Kjell Nelin article on D-jet fi system for the 914 and the MPS checks out, the temp sensor chks, the cold start chks,the plenum temp sensor chks, the fuel pressure chks. I can hear the pump run and it pumps enough fuel. I can hear the Fuel injectors doing the burr sound when you push the throttle down with the key on. All I know is that it ran when the top shaft came loose in the dist. and pushed the rotor into the cap and it still ran but I opened it to find that because the dwell was off,lol. I fixed the shaft clip and replaced the cap and rotor and set the points then and have static timed it using the light method by turning the dist. with the timing mark in the hole. I did have a broken point plate wire before and fixed that by soldiering a new wire on and it has o resistance and shows continuity to the plate. I cant believe it wont start when it ran with the rotor boring in the cap and before I rebuilt the motor it ran with a hole in the number one cylinder head the size of a screw driver head and sounded like a exhaust leak,lol! She actually ran pretty good just loud,lol! I actually found a new point plate for the dist. and ordered a new blue coil though the old one had continuity and a resistance of 2.5 ohms between - and + and 9.37kohms between - and center which I dont know if is good? Any suggestions? I'm gonna pull the injectors out again even though it ran before in this state and check for leaks and spray? LOL I'm not giving up on her this is a good learning curve for those road side breakdowns,lol! Thanks, Bill

[raygreenwood]

Several things. Since the top shaft came of...make sure it went back in the right way. It sounds like you are 180-90 out of time. Also check that the trigger points are operating properly. Also check the springs and weight assembly.

This can also be caused by a breaker plate assemblt that is either warped and sticking from trying to solder it (I did that)....or a plate that reads continuity at rest...but has a bad connection or a poor copper braid...so its breaking connnection as it advance. I have done that too. Ray

[Vgonman]

If you did not do it at the time, give that distributor a good cleaning and lubing............if the trigger points are shot you still can get them from Bosch I remember under $100 when i got mine.

I think a lot of these cars got stood up whne the trigger points failed. I have seen many of these cars with between 75 and 100k miles on them turning into rust..........I know with mine that was the problem.it fired right up when i replaced them.........but i wanted to rebuild the motor anyway so i knew where i stood...........and while i still could find the p and c and other odd bits.

[vwbill]

Hey, It's alive! I pulled the dist. and put in the new point plate, but didn't put the new blue coil in since the old one seemed to have better resistance then the new one,lol! She turned over first try! I just have a question on where the rotor should point when the 28 degree mark is lined up?
So is it correct to set the mark(red) in the timing fan hole when the number two exhaust valve is opening then the rotor is pointing where, to the number 4 cly. or to the cooling housing? My dist doesnt have any marks on the edge. Mine was pointing to the #4. cyl. So I set the timing by turning the dist with a light to the point plate deal so it just goes off then back till it lights. I didnt change the point gap even though it was set a little bigger then .016" from the factory on the plate. I didnt check the timing with a light or the dwell yet; I was chasing fuel leaks first! One up front near the pump was crazy since I put new line in and found a leak in the middle of the line when I grapped it? I kept changing clamps thinkin that was it,lol! All the injector resistance chks. 2.5 ohms but I think one is leakin near the plug plastic? Can they leak there? I need to get the fuel leaks fixed before I set anything! I did try to idle it down but turning the screw in just lowered the idle, not all the way down? Is this a vacuum leak or a internal leak like the cold start inj or the injectors them self? Well I'm just happy she cranked!! Yeah!! Thanks for the help! Bill

[raygreenwood]

Yes, the injectors can start to leak at the plastic. Its a goner...but a good core for a rebuild trade in. The idle issue could be a vacuum leak, but usually that would cause other problems. Most likely, its the timing being too advanced. You must put the light on it. Try 10.5* BTDC at idle with the timing light...and about 30 BTDC at 3500 rpm. Ray