what's happening to my engine!!!!!

[zeiss150]

I've got problems! I just put my new F54 N42 engine in and I'm having a hell of a time. It seems to idel ok but when I give it a little gas it back fires through the carberator and dies. Then if I just let it idle and shut it off it with "deisle" for at least 20 or even 30 seconds then it spits out a blast of gasoline through the carbs. What the hell is going on? Is my timing off and would that make it "deisel". HELP!

Matt-

[zoom240]

You're probably way past this, but I've had something like this happen to me when I got the firing order wrong. Are you sure? It's possible for the car to actually run with the firing order 180 out - but of course not well.

Dave

[Razor]

Hey

I had the same problem but with different car

my daily driver car

I installed a new carb DGV series weber and EXACTLY the same problem

I checked the timing, idle, mixture, even spark plugs, checked all hoses as well in case of any leak and they are all OK

I found out its the carburettor's fuel pump nozzle is pretty worn out. Bought new one and works fine now... still getting the excess fuel after engine shut off though.

I havent check the timing after carb tuning might be the culprit (too advance)

[beandip]

Zeiss150 I tried to post last night but was having trouble with the PC. From your description , it sounds to me like there are more than one thing going on. First check the plug wires to be sure they are in the right fireing order. Secound check the timing with a timing light , you said the eingine will run right ? If these things check out . Cam timing is my next thought . Only if you had the head off , or the timing chain off. As for the deiseling , this could be from a rich fuel mixture. Are you running SUs or what? Often the poping back thru the carbs is from a lean situation , but with the deiseling and spraying fuel , not likely. Another thought . What dist. are you using ? There could be a malfunction in a module of an electronic dist. All together it sounds to me like ignition coupled with a rich mixture , check the float levels , if they are set too high this could cause the richness also make sure the chokes are adjusted correctly so that they are off when the lever is all the way forward . Also in this area , see that they are not sticking open . If when you touch the mixture adjustment knob of the carb it snaps up or clicks up a little , this could be the fuel problem. This is about all I can think of . All the best , Gary

[zeiss150]

Hey Gary,

I put a timing light on it today and The timing is Way off, it's retarded about 20 degrees. So I figure that the oil pump is not timed properly. So I'll drop the oil pump and turn the distributor shaft untill I get the timing right. I think that should fix the deiseling and the other problems. I must have goof'd it when I put it in ... ooooops!

I'll keep every one posted

Rock on Z people!

Matt-

[zeiss150]

Hey guy's I just wanted to up date you on what's going on. I droped the oil pump and moved the dizzy shaft just one gear over and bam! I put the first hundred miles on it today. It's still ideling a little rough but I figure that its just a carb adjustment.

Thanks for all your help guys.

Matt-

[Bambikiller240]

Matt:

Do you recall the correct orientation of the dist driveshaft that got your car running? Take a look at the attached picture and let me know if either of the pictured orientations looks like what worked for you. Thanks!

Carl

[zeiss150]

Hey Carl, It's the picture on the right.

Matt-

[Bambikiller240]

Originally posted by zeiss150

Hey Carl, It's the picture on the right.

Matt-

Thanks for the confirmation, Matt. That is exactly what I expected. The picture on the left shows the dist driveshaft oriented according to the pictures shown in the FSM, Haynes manuals, and any other manuals I have looked at, and appears from my experience (and yours) to be incorrect. When I had the dist. driveshaft of my engine set that way the rotor did not point to the #1 lug on the distributor cap when everything is set at TDC. I couldn't even get my engine to start. The picture on the right shows the dist driveshaft as it appeared prior to disassembly of my engine, and how I had to reinstall it to get the rebuilt engine running.

Interesting that this incorrect orientation picture could exist for over 30 years and not be corrected by either the Nissan company or any other publisher of automotive manuals. No wonder so many of us have had problems with installing everything "one tooth off" when assembling engines.

[sblake01]

Good call, Carl! I first discovered that about 30 years ago on my 510. That '11:25 o'clock' thing in most of the books is crap! You can get them to run that way but when set at your 'right' view, you have the full range of timing adjustment. I had forgotten about that because it's been a while since I've pulled an oil pump.

[Bambikiller240]

Hi Stephen;

Yeah, I had noticed it back in 1980 when I rebuilt my first (and only, up until this year) engine. It seemed like the description should have been 11:28 instead of 11:25, and the picture didn't match the way the shaft needed to be. In the years after 1980 that memory kinda faded and I wasn't totally sure I was remembering correctly, but when I went to adjust my recently rebuilt engine (shaft set to match the FSM picture) the darn thing wouldn't start unless I maxed out all of the adjustments and even then it ran like crap.

That darn picture appears in so many places, and folks like me who don't do engine work very often depend on the FSM or other manuals to guide us properly.

Do you guys think it's worth documenting this issue in Tech Articles?

[Victor Laury]

Originally posted by Bambikiller240

Do you guys think it's worth documenting this issue in Tech Articles?

Absolutley! Your dizzy tech articals are already of value... a little more can't hurt!