Zirconocene

You can buy injector cleaning setups for pretty cheap on Amazon. I'm not suggesting that you use it for cleaning but one of the nice things that it does is pulse the injector really quickly while you spray carb/brake cleaner. What I like about it is that you can hear the clicking very clearly and have full confidence that you've got pressure at the injector (so long as you're pressing on the nozzle of the can). It would at least help you see if you have some internal blockage in the injector(s), separate from the valve opening/closing as evidenced by the clicking.

Cheers

smai

We might be on to something. Probably not a good thing, though.

The Fabricator was likely fine. I drove it home from his shop (the first and only time its been driven more than a 1/2 block in 2 years), and it ran for a few weeks after until I plugged my fuel pump. It never ran well, but I think that was the aforementioned vacuum hose mismatch.

But the Fabricator didn't finish all the joints, and despite buying $22 exhast clamps, the union between my Y-pipe and the bolt-on cones at the end of the header leaked exhaust like a sieve.

So I pulled out my MIG welder that I bought at the Farm & Fleet because I wanted to learn to weld. But my only welding experience consists of a failed attempt to weld the backrest on to a cheap barstool.

Could I have fried my computer? Say it ain't so.

I'm reading that its hard to test the computer itself, but I've found some posts on the 35pin connector testing. Is that a starting point?

soontobered84

Call Roger. I believe that you can send him your computer for testing. and if it tests bad, he can have it fixed through JDS

smai

I still don't have an answer, so I've done more testing. Basically, I've got a noid light and injectors that spray when forced... but not when the L-jet wants them too. I believe I have to look into that computer. Would that explain those symptoms given the information below?

Confirmed - injectors are not spraying; removed injector #5, turned the engine, no spray
Confirmed - Injectors confirmed spraying with 12v directly applied. Amazon "pulse" tester did not. I might be using it wrong though.
Confirmed - 12v from either terminal of the injector plug with the ignition on
Confirmed - 12v at term 30 of XVI AFC Relay
Confirmed - 3 ground wires on passenger cam carrier (#1 injector, #4 injector, right by the pulley). All show .3 ohm or less resistance to other grounds. All show battery voltage when tested between ground point and hot post.
Confirmed - 39 psi fuel pressure at the fuel rail
Confirmed - fuel pump engages and runs. Confirmed 1100 CCs of flow rate per WSM (new fuel pump and filter April 2024)
March 2023 - New Bosch Green Wire (yes, I've been working on this that long)
April 2023 - New Fuel Pump Relay
5/19/24 - New AFC Relay
5/19/24 - replaced engine block ground strap and battery and cleaned contacts;
Also, FYI... this features Cat Delete, Air Pump Delete, and vacuum decelerator delete.
All tests of 35 pin connector seem to check out (values 66 degrees F):

• Terms 5/13 - Spec: 2-3k ohms - Reading 3.7k
• Terms 2/18 (loose pedal) - Spec: 0 ohm - Reading: 0 ohm
• Terms 2/18 (slack removed) - Spec: 0 ohm - Reading: 0 ohm
• Terms 3/18 (pedal up) - Spec: 0 ohm - Reading: .0L (No contact)
• Terms 3/18 (pedal down) - Spec: 0 ohm - Reading: .3 ohm
• Terms 6/9 - Spec:200-400 ohm - Reading: 560ohm (a touch high)
• Terms 6/8 - Spec:130-260 ohm - Reading: 360ohm (a touch high)
• Terms 6/9 - Spec:40-300 - Reading: 200ohm
• Terms 6/9 - Spec:100-500 ohm - Reading: 300ohm
• Terms 27/6 - Spec: 2-3k ohm - Reading: 2.9k
• Injector Terms (10/15, 10/14,10/32,10/31) - Spec 1-1.5 ohm - Reading 1.5ohm
• Terms 16/gnd - Spec: 0 ohm - Reading: 0 ohm
• Terms 17/gnd - Spec: 0 ohm - Reading: 0 ohm
• Terms 35/gnd - Spec: 0 ohm - Reading: 0 ohm
• Terms 5/gnd - Spec: 0 ohm - Reading: 0 ohm
• Terms 1/gnd - Spec: 1 volt - Reading: 1.1 volt
• Terms 10/gnd - Spec: 12 volt - Reading: 12 volt
• Terms 29/gnd - Spec: 12 volt - Reading: 12 volt
• Terms 4/gnd - Spec: 8 volt min - Reading: 10 volts
• Terms 1/gnd - Spec: 2.5v - Reading: 3.5 volts

Mrmerlin

you should also add in that you mig welded the exhaust system ,
and could have possibly damaged the engine computer.
usually you would disconnect the engine computer before you weld.
That said the easiest thing to do now is to put your computer into a known good running machine

smai

Yes... after rechecking the timing and all the above, I am resigned to the fact that I fried my computer by attempting some amateur welding.

I've got a line on a local replacement and have started looking into testing. If I do confirm that was the root cause, I will share.

smai

I ordered one from Ebay today. Asking price was $300 untested and it had a "make an offer" button. I offered $200 and he accepted. It comes this week. I figure I can resell it if its not the root cause (and I prove its good). I'm guessing I'd be out $100+ just to test the one I have, or I'm out $200 if its DOA. Not a lot of great options. But I'd gladly pay $200 to finally win this 2+ year battle.

Also... I found these guys on the Internet. Seems like they are experts... and the guy was super helpful over email. Would have gone with them but the ebay seller accepted my offer overnight.

https://electronikrepair.com/about-us

Tom. M

Rich is the OG brain rebuilder. He's been part of the 928 community forever...and a day. If you run into issues with the ebay guy, go to Rich.

Mrmerlin

that link you posted is for Rich Andrade