White '73 99LE Notchback

[DrewP]

It seems that frustration is the name of the game with '73's lately.

David and I tore into the white car today and made.... almost no progress.

I'm 98% sure the D-Jet manifold pressure sensor is bad, has no change in resistance on either circuit even after I took it apart to apply contact cleaner and check it out inside (the damn thing is riveted together, has a metal diaphragm spring attached to a linear slide pot to send a signal for changing manifold pressure).

The TPS was also way out of wack and sending intermittent signals.

And the extra fuel pump (external roller pump) that I had on the shelf decided it didn't want to spin anymore.

We monkeyed with the D-Jet stuff for most of the day and wired in an extra Walbro external pump and it would still splutter a bit on starter fluid, but absolutely nothing while cranking with just the D-jet stuff.

Pulled off the intake manifold and swapped in a whole CIS setup that I had boxed up that came with my yellow '73. It worked and I drove the car with it a few times when I boxed it up.

Not anymore! 3 of the injectors leak a little bit just with the pump running, and the delivery does not increase when I lift up on the metering plate with the pump running. WTF. (When we pulled it out, the plate was stuck down, David pulled the filter basket off and dislodged it, now it floats up freely, but doesn't increase the pressure to the injectors.)

Grrrrr.... I'll probably tear down the CIS metering block on my desk after work this week and see if I can figure out what was going on. Hopefully something just popped loose from dislodging the metering plate.


Good news is that with the 3 leaky injectors it would sort of run on one cylinder, and splutter on 2 more, so making progress!

[Jordan]

Two suggestions:

Weber
Trionic

That is all :)

Actually, LH would not be too hard if you had a doner.

[SwedeSport]

CIS stuff hates to sit. Gums up over a few weeks.

Make a custom manifold and put a Holley 2 bbl on it.

[DrewP]

We were talking about doing just that. This car is gonna keep the stock engine, T5 seems like overkill. LH more doable, just the little bit of fab work to mount the injectors to the D-Jet manifold.

It's so close to going that I think I'll put a little effort into getting the CIS going enough to move it around, and then we'll go from there.

[Luke]

We were talking about doing just that. This car is gonna keep the stock engine, T5 seems like overkill. LH more doable, just the little bit of fab work to mount the injectors to the D-Jet manifold.

It's so close to going that I think I'll put a little effort into getting the CIS going enough to move it around, and then we'll go from there.

If you decide to go that route I've made a couple of billet fuel rails for Djet manifolds to take modern injectors and the banjo fittings and could make another one.

[Crazyswede]

I am pretty sure the LH injectors drop right into the manifold without issue. I think the retaining rings that hold them in place even fit properly. You will need some sort of clamp to hold the fuel rail in place.

[saabfan9]

kinda too late now but mine will run with the intake sensor unplugged also with the pertronix i have to run 1 tooth advanced i know it doesn't make sense but after dicking with it so long i finally was able to get it to run right.. still fresh in the wood safe

[DrewP]

I'll keep that in mind. I picked up a fuel pressure guage kit at Harbor Freight at lunch today ($20, couldn't go wrong, right?) and get the timing light out and running right.

[Geoff]

Did you get a NIST calibration certificate with that $20?

[DrewP]

Maybe, but I wouldn't know for sure. I don't read Mandarin so good.

[DrewP]

IT RUNS!!


...Kind of....


Question: Timing marks on the B20, do you really reference off the timing mark that's at like 1 o'clock position? It's scribed on a flat on the casting of the block?



Combination of things going on.

The fuel pump we plumbed in wasn't building enough pressure was one, only about 45 psi on the inlet with engine off. Service manual calls for ~65-70 psi, higher capacity pump fixed that.

Second was after further investigation found that the air metering plate was very stiff going up, and was not returning to position when it was lifted up. David tore the fuel distribution block apart and cleaned all the varnish out of the block and off the metering piston so it slides freely in it's little bore. VERY simple, nothing to be afraid of with those as long as you keep everything clean.

Then found two injectors stuck shut, that was an easy fix, spray them all continuously into a bowl and just rap on the shafts and near the tips to dislodge the junk in there and eventuall they all started spraying freely and make that funny *schreeeeeech* sound that they make.

Something funny is definitely going on with the Pertronix trigger kit though. The timing does end up wanting to be set between where the mounting screw goes - I have a feeling it's because the early and later distributors don't line the hall sensor up the same, especially since it looks like they take different points.

[saabfan9]

i finally got mine running well (idles a little high though) if it helps in anyway i can take some pics where i have mine set with the pertronix tdc

[DrewP]

I have gotten some good work in on this in the last week.

Finally have the CIS system that came in my yellow car dialed in decently. Revs nicely at idle.

The ignition turned into quite a snowball. I ditched the Pertronix kit entirely and have the correct left-handed points in there now and it sits right where it's supposed to adjustment wise and it seems much happier. The mounting plate for the Pertronix pickup is just in the wrong spot in that distributor.

Most of the electrical issues were solved with a nice soak in some Deox-It (fantastic contact cleaner), so now lights, interior stuff, temp gage, radiator fan, all seem to be working as well as can be expected with the ceramic pinch fuses....

The alternator wasn't charging because the external voltage regulator that came on the '73 isn't working, and the field energizing lead wasn't getting switched +12v, so I just strung a lead to the fuse box into the switched + block, so that works great now.

I still need to pull the water pump cover AGAIN because I must have got it installed with just too little clearance. Sometimes the pump shaft floats up a little and the impeller screeches and clatters against the cover.

I'm half tempted to drop the D-Jet stuff back in since I'll have the intake off anyway to get to the water pump and see if it will run correctly now that the ignition stuff is sorted. When it was on there originally I did get all the injectors firing and looked like they had good spray pattern during cranking. It may be good to go.

As it sits now, waiting for a little more love, a set of tires, and paperwork to get plates.

[Sam]

If you do decide to go d-jet again, pretty much everything is available. The TPS ($60) is available on rockauto, as well as high quality rebuilt injectors which are $25 each. A large cache of the MAP sensor, AKA the d-jet "grenade" has surfaced on ebay. Porsche and other brands used the same part with different calibration. Do a search for 'bosch manifold pressure sensor' on ebay. The fuel pumps are a lost cause, although bosch heritage will probably sell you one for $1000 it doesn't seem reasonable.

Still struggling with my d-jet system this weekend. I killed the old 900 pump i was using the same way you did. The second circulator hose pumps more air than fuel. I bought a few clear fuel filters to help me judge fuel pressure and to look for any varnish that may accumulate.

[DrewP]

I should have got a photo of the pump I have in there. It's an older Walbro universal with threaded ends on both sides that I put barbed fittings on, it worked fine for CIS, it's just noisy. I'm going to order one of the GSL392's like Luke suggested for it since they really are $100 and everyone carries them.

Good to know about the MAP sensor, I think that's the only part I'd actually be suspicious of, I already checked out the TPS and know the injectors flow well.

I got the water pump cover off last night and cleaned everything up, going to try re-assembling everything tonight after work and see what happens.