Another fuel injection problem please help!

Jake Hoff

I have a 79 bug with a 76 fuel injected bug motor in it bought it as a unfinished project that needed a new fuel pump before any thing could be diagnosed. Installed new fuel pump and replaced all fuel lines with gates barricade and the right fuel clamps. New filter blew throughout the old steel lines with compressed air and cleaned the tank.
Adjusted the valves checked compression replaced the CHT because the old ones wire was about in two
Replaced all the vacuum lines cleaned plugs,new cap rotor points wires looked good. Timed it statically turned the key and it started! dialed in my timing and dwell checked for leaks
Watched fuel pressure with gauge around 35 (with a harbor freight gauge)

Could hear a vacuum leak around the boot so decided to stop and get some new parts
But was running very well
While replacing the old intake boot I saw that the throttle valve sensor was a little chewed up and started looking at it and thought it would've nice to replace it with the S boot so ordered parts and installed them went to start the bug and would actually fire for a second or two and nothing. Would just crank. So I went behind while cranking and opened the throttle wide open and it spun faster and sounded like it was going to start but when you let off the starter she would barely run with the throttle wide open but would die in a matter of seconds. Now when it was barely running I mean it was way low on rpms with full throttle just would not really pick up and go

I have checked the fuel pressure
Cold start valve checks good as far as manually spraying in a bucket I did run all the electrical tests before I had this started the first time
Thermo time switch is working
Auxiliary air valve looks like it's working
The AFM was working fine and tests good

What am I missing

Please if you have any idea let me know. I was going to surprise my wife with a drive in this thing for our 10 yr anniversary next week so am tying my best to figure this out

I have spent hours on here and think I have read every thread about fuel injection and have spent a lot of time at IAC

Thanks everyone

VWCOOL · Posted: Wed Mar 19, 2014 10:33 pm Post subject:

Sounds like fuel pressure. Did you dislodge the vacuum line to the pressure reg? Is the pump still working? I had a bastard of a time with my fuel pump until I discovered it was earthed at the left headlight earth!!!

Jake Hoff · Posted: Thu Mar 20, 2014 4:16 am Post subject:

The pressure reg is old but when I crank I have steady pressure and when it acts like it wants to start it holds pressure never see a drop in pressure. I did remove the vac line when it was running fine before and the pressure dropped then
I manually tested my CSV last night and really seems to put out a nice spray pattern so even if my gauge was way off I am still getting enough to open it

I should have said all the time from when it was running good to now has only been about a week

Thanks

Go_Bug_n · Posted: Thu Mar 20, 2014 3:29 pm Post subject:

Have you checked to see if your crankcase vent hose is tight and connected at both ends? That would be a huge vacuum leak and the AFM would barely open.

From my own experience, those hoses rot out and barely hang on to the nipple that comes out from the oil filler. If you need another crankcase vent hose, get this:

http://www.airheadparts.com/vintage-vw-parts/new-l...81129651-c

Be sure it is on tight. You'll probably have to remove the oil filler neck to ensure that the hose is on fully and clamped.

Yehan73 · Posted: Thu Mar 20, 2014 3:58 pm Post subject:

As another FI owner, before you go down rabbit holes do the following.
Open the S boot. Spray some fuel down the throttle body. Out the boot back. Start the car. If it starts for a second, you have fuel issues. If it doesn't you have spark issues. Remember any good mechanic starts with the simplest and moves to more complex solutions.

Jake Hoff · Posted: Thu Mar 20, 2014 8:23 pm Post subject:

Yes replaced the crankcase breather hose. I took off my fuel pressure gauge and went back to my old throttle valve switch and it started. Not very good but it started
So was trying to time the engine and could not get it to time at 5 ATDC the motor would idle down to around 600 rpm and would not accelerate with the throttle
So I put the timing to around 5 BTDC and it idle higher and would accelerate with the throttle
I did spray the engine down with carb spray and did not notice a vac leak

Stock DVDA. Numbers match for that engine serial number.

Then after I turned it off I checked for some leaks and the darn thing would not start back up would just crank and crank

What should I be looking for next

Thanks for the replies

Jake Hoff · Posted: Thu Mar 20, 2014 8:25 pm Post subject:

Also there was quite a lot of heat build up on the 1/2 side. You could touch the engine tin on top but it would get uncomfortable
And on the 3/4 there seemed to be no heat at all
Car ran for 3-5 minutes

Go_Bug_n · Posted: Fri Mar 21, 2014 4:59 am Post subject:

Is the throttle switch out of adjustment? It's possible that the EGR valve is open, even at idle.

Disconnect and plug the vacuum hose to the EGR valve and see if that doesn't help with the starting and idle. If it does, then the throttle switch needs adjusting or, the EGR failed in the "ON" position.

Jake Hoff · Posted: Fri Mar 21, 2014 7:05 am Post subject:

I read your post on the EGR so have disconnected it and plugged the vac line.
I adjusted the throttle switch as per Bentley where you twist it towards open throttle until you feel resistance. It tests good itself but will put the new one back on tonight.
I took a crappy video with a I pad and will try and post it today

I don't like to replace parts blindly but I don't know about this one

I read a post last night about some bodies 3/4 hotter than the other side
And the consensus was that maybe those two weren't firing. So will try and rob parts off another car and see if I can diagnose a little better

Randy in Maine · Posted: Fri Mar 21, 2014 7:23 am Post subject:

Do this...

After you confirm that the rotor and distributor cap are in good shape and have confirmed that the dwell angle really is 47º +/- 3º , hook up your timing light and confirm that all of the plug wires are indeed getting current to the plugs.

You could also test out the igniton wires to see if they are pretty much the same for resistance using your ohm meter.

I would time this thing with the vacuum hose(s) removed to about 30º BTDC +/- 2º when all of the centrifical advance the distributor has to offer is all in which should happen at about 3800 RPMs or so.

If this is a DVDA, if you remove the retard vacuum line, the timing should immediately jump to 7.5º BTDC from the 5º ATDC at idle.

Weezle · Posted: Fri Mar 21, 2014 8:45 am Post subject:

THIS:

Jake Hoff · Posted: Fri Mar 21, 2014 8:11 pm Post subject:

Randy
Checked and all 4 wires were firing
Cap and rotor checked out
Never ohmed my plug wires though
Dwell was at 49
It is for sure a DVDA
But when I pull the retard vac line while shooting timing at idle I see no change in advance
I know this is not good but this would not lead to my problems would it?

Weezie I had read your topic and scraped those grounds and put a new stainless screw in them .
My fuel pressure has always been there while starting and while running

But now when it runs kinda for awhile but if it dies or I turn it off there is no starting it back up

I know this sounds like what others have had with a vac leak and the CSV is dumping fuel in at startup but I can not find a vac leak to save my life

I appreciate the help I have been through about half the 27 pages of fuel injection post in here and still nothing

satterley_sr · Posted: Sat Mar 22, 2014 9:42 am Post subject:

Did you accidentily reverse the 3& 4 plug wires? Easy to do and it will run like crap on the 1 & 2 cylinders.
_________________
DDC racing

Weezle

When my car was running poorly ie hard to start and couldn't maintain idle without stalling I removed the vacuum line going to the retard port on the dizzy can and it ran great after that. Used rubber plug on the vacuum port off the throttle body.

Go_Bug_n · Posted: Sat Mar 22, 2014 6:38 pm Post subject:

Jake Hoff · Posted: Sun Mar 23, 2014 5:23 pm Post subject:

Plugs wires are right but I think I am going to send my injectors off and buy a SVDA
The whole starts and runs until I shut it off then just cranks is really bothering me
I will replace the boots on the intake manifold then check my aar for leaks and post back on what it is doing
Thanks
Any other ideas are appreciated

Jake Hoff · Posted: Sun Apr 06, 2014 12:13 am Post subject:

Just received and installed my cleaned injectors from Cruzin performance (2 were plugged by the way)
Replaced AAR hose
Clamped 2different suspicious vacuum lines
Cleaned and tore apart my EGR piping etc to the throttle body
Bought some serious clamps for my new S boot

Starts and runs fantastic I haven't test drove it just because it got to late

Initially I started and immediately noticed a huge power increase and let it run for close to 10 minutes then stopped it and started it repeatedly a couple times and every time I started it back up it ran awesome

Will still probably replace my distributor when funds are there but right now at least I can say I have a running vert

Thank guys for the help

Randy in Maine · Posted: Sun Apr 06, 2014 8:55 am Post subject:

You are doing OK Jake.

I have always been very pleased with Rich @ cruzins work.

If the advance side of your DVDA will not only hold a vacuum (from your hand vacuum pump) but will also move the advance plate inside the distributor a little...I would use it.

Time it as you would any ..... 30º +/- 2º at about 3800 RPMs with the vacuum hoses off. Tehn set the idle speed adn reattach the advance vacuum hose, leave teh retard side open at the distributor can and plug it at the throttle body.

Jake Hoff · Posted: Mon Apr 07, 2014 8:41 pm Post subject:

Thanks for encouragement Randy timed as per your rec and
Was able to drive up and down the street yesterday with it feels good through 3 gear but felt just a little doggy in 4. But would really want to drive it for a while to confirm that.
Once I feel comfortable with where it's at I will probably bust open the AFM and just have a peek in there to see what it looks like
Really good feeling of accomplishment on the fuel injection working after hearing so many mixed reviews on it.
Now to just paint and seal it up


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