Bill Ball

I wish I had my camera with me.

I've been helping a local 928 owner with his 88 S4 that was idling badly and dying. He had it in a local shop for months and accumulated a big bill but the problems persisted. We did some tests and nailed down a bad ISV (NO movement at all despite WD-40 and direct power test), vacuum leaks (bad 4-way) and a bad O2 sensor (never read over 0.1mv). Everything else checked out. ISV on order, fixed the vacuum leaks and the O2 sensor.

Other than the idle the car didn't sound right to me on the juice either.

Today we pulled the intake to remove the ISV while we wait for the new one. When we pulled the fuel rails, the injectors came out very easily with the rails --- too easily. The lower o-rings stayed in the manifold in 6 of the 8 holes! Wait a minute... They are supposed to be held on the injectors by the pintle caps. In one hole there was no o-ring or pintle cap and none on that injector! In 2 other holes there were no pintle caps, just the o-ring. In 3 other holes the pintle caps and o-rings were sitting there in the manifold.

These are real nice 4-hole Ford injectors. Somebody must have removed the pintle caps to put on the correct o-rings, although you don't need to do that to change the o-rings. Anyway, they were barely pushed on the 2 injectors that came out intact.

So, assuming all had pintle caps and lower o-rings originally, and we could not see any in the valve pockets, the engine must have ingested a few.

One injector plug was not attached and several spring clips were not seated properly.

We reassembled the injectors and seated the pintle caps, which fit snugly as they should. I suspect the car will run A WHOLE LOT better after we get it back together tomorrow.

I've never seen injectors come apart like this when removing the rails.

Oh, the other funny thing we found - the diagnostic plug for the LH/EZK would not power up the Spanner. I popped the cover off the 14-pin plug and using the wiring diagrams, I found every wire was in the wrong pin location. Got that sorted out and the Spanner worked perfectly.

Mrmerlin

Thats interesting Bill, I would bet that someone didnt realise how far to seat the pintle caps, it definitly helps to add some WD40 and hit them with a hair drier to warm them a bit before trying to install them. If the tips are cold its not uncommon to crack them while pressing them on BTDT. I use a small 12 pt socket to press them on, but I know there must be a proper tool to do this.
I wonder if it would be a good idea to do a compression test to see if any of the cylinders are damaged

Bill Ball

Yes, I've cracked a few putting them on as well. We still have to install the 3 missing ones tomorrow, but the other 5 injectors went together just fine.

Black Sea RD

Bill (and Mr. Merlin too),

Can you clone yourself so you can be at multiple locations around the country? I'm sure many a bad running 928 has similiar problems that would escape the regular DIYer trying to figure it out on their own. BTDT.

Man has this community come so far since the early 90s when I bought our very first 928 in SLC, UT. Kind of like comparing the Dark Ages to the Renaissance period of History.

Keep up the good work and posts,
Constantine

AO

Awesome work Bill! Damn PO's.

ROG100

Bill,
Do you need replacement O rings for the Ford Injectors?
Roger

IcemanG17

The newer style 4 pintle design injectors do work well...IF they are sealed properly.... The stock 14mm O ring that comes with them DOESN'T work....but the fatter 16-16.5mm O rings do...this was a VERY expensive lesson for me!! So 8 vac leaks at every injector make for a very sick shark!!

However sharky does seem to be running VERY well lately...it seems like the injectors might have found a few HP too....

Bill Ball

Roger, thanks, I have some spare injector seal kits, so we are good to go...

However, now that I think about it, I probably have the wrong pintles for the ford 4-hole! My kits are the Bosch 928 kits. Can I just drill out the center hole to match the 4-hole size or are they the same? I don't have 4-hole injector here at home.

[To answer my own question, it appears the pintle caps in the kits for our injectors are UNIVERSAL 1.5mm hole and will work with both single a 4-hole injectors].

Mrmerlin

Bill IIRC the 4 holes might have a slightly bigger opening than the single point injector, i think there might also have something with the colors of the pintle caps as well

Imo000

I don't think the pintle caps are important at all but the O rings are. I don't think you would notice any difference if the caps were missing.

Bill Ball

Well sure, there is enough of a lip in the manifold port that the o-ring shouldn't fall through into the motor. We did find the missing o-ring, so it didn't get ingested. However, 3 pintle caps did. They will get ingested if not firmly seated. So, either seat the pintles or leave them off, eh, Imo000?

928autobahndreamer

x 1000000000000

I would be willing to go in on the cloning cost for a Bill Ball in Missouri

ROG100

The injector seals I have are 8mm x 4.5mm and Viton. That's 8mm ID and 17mm OD.
I have not fixed a price for them just yet but about $2.50 each will not be far off.
Much better than buying the $12 seal kit.

Bill Ball

Roger, that is a good price! We have enough from the seal kits I bought ages ago.

JHowell37

Honestly the pintle caps and o-rings wouldn't bother me too much. Yes you should get them sorted out properly, but it's not a huge deal. I would be more concerned as to why the pins on the diagnostic connector have been moved around. That would be a little disconcerting because it suggests that the last person to work on the car had the right amount of knowledge to be a danger. I can't imagine any good reason to move the diagnostic pins around.