Well, my handyman and I finished the injector swap (for idiots) today and I am pleased to report that all seems well.

The installation passed the pressure test with flying colors and, after everything was buttoned up - excluding filling up with coolant - the engine started in good order and ran fairly well.

We topped off the radiator, having drilled 1/8" bleed holes in the thermostat and "burped" the radiator by topping it off while maintaining 2,500 rpm. The test drive also went fairly well. The engine does have a bit of hesitation and stumble off idle, but the fuel is about a year old, with no stabilizer added. The coolant temp averaged about 200° for a ten minute drive , but went to 235 as we were idling and backing it in the garage. The fan did come on at ~230°. I think the radiator may need another topping off.

All in all, it ran much better than it did a year ago when I consigned it to the garage. One thing of concern to me is that the injectors I removed all showed between 18-20 ohms resistance save one which was at 16 ohms. I would have thought that one would be wildly different, as that is what a mechanic told me when the car was running very badly.

I don't really care at this point, as long as it continues to run well.

The major problem we had during the changeover came when one of the retaining clips broke while removing the old injectors. The instructions for the new injectors stated quite clearly that we were to re-use the old clips.

Consequently, we called a halt to the project and attempted to locate new clips. I finally found a Chevy dealer who could get some in a half-hour. Since it was a 45 minute drive to get there (30 miles or so one way) I ordered them and we hopped in my truck to retrieve them.

On our return, my partner tried to install the new injectors in the fuel rail using the clips. THERE WERE NO SLOTS FOR THE CLIPS ON THE NEW INJECTORS! I re-read the instructions for the injectors. Only after the instructions to re-use the clips did it say that no clips are necessary on the type III injectors. By not stating this fact up front, it cost us two hours of unnecessary time and driving.

So, BE WARNED! Clips are not necessarily needed when changing injectors. Had this been noted in the instructions - UP FRONT - it would have saved us a lot of time and trouble (as well as ~$8.00+ for the clips and a 60 mile drive). I mentioned we were newbies when it came to this and I'm sure Jon thought it would be obvious in the instructions. It wasn't and I hope he revises his instructions.

Anyway, the car seems to run fine and I am much happier than I would be if I had spent the $1,400 the local mechanic wanted for parts and labor for the job. Now it is running and the weather is good, I think I will have to gracefully refuse the invitation to display my roadster at the LeMay museum in Tacoma for the next four months. While I would love to show it, I would rather drive it. I may not be on this earth in four months, so I'd better enjoy it now.

Thanks again to the great members of this forum who gave me the benefit of their wisdom in accomplishing this job. You guys ROCK!

 

Sometimes the injectors will fail when they get hot, so that might explain what you saw.

 

The car would not fire when it was cold and I wanted to drive it home from a shop. After doing some research about the F.I. system on this forum, I went back to the shop and asked the mechanic to remove the plug from the injector he said was bad.

The car fired right off and I drove it home with seven injectors. So, there was a bad injector at that time, even when cold.

It's academic now, though. I have Jon's rebuilt Bosch III injectors installed, it runs fine and that's the end of that chapter. If anyone wants the old injectors (including both the seven old clips and five new ones I didn't need), speak up and I'll send them your way.

 

The Bosch III injectors are a little longer than the stock ones.

I broke a clip (stock injectors) and left it off. I figured the injectors are captive between the rail and the intake manifold so they aren't going anywhere. I had a leak at the injector rail. I tried prying the injector up into the rail with a large screwdriver but that didn't stop the leak. After I replaced the clip the leak was gone.

 

Congrats !

yes, as stated the inj can fail in other ways. They can short internally as well as short externally by arcing to a nearby ground point. If ONE INJ shorts out, that entire bank shorts out. THAT is why it would not run until you unplugged the bad inj.

 

The clips aren't needed if you follow Jon's instructions correctly.


1) Install the Bottom of the Bosch III injector First into the intake manifold.

2) Install and bolt down the fuel rail.

3) Connect fuel lines and pressurize the system and check for leaks.

Also, Use Liquid Dish soap to lube the O-Rings, Not Oil which does not evaporate like dish soap and will attract dirt and contaminates resulting in premature wear to the o-rings.

I've installed two sets of Jon's Bosch III's this way and have had zero leaks.

 

True. The problem arose when I read just the first instruction, which said to re-use the clips. I stopped right there because we had one broken clip.

We then drove 30 miles to the Chevy dealer and bought a package of five new clip. Then we drove 30 miles back home.

When we went to install the injectors, we then noted there were no clip slots on the Bosch III injectors. Going back to the instructions, we found in the next sentence the III's don't use the clips.

When I spoke with Jon's shop to confirm this, I asked him if he could change the order of the two sentences, so a novice would immediately see that the clips aren't needed on that type of injector.

Case closed. I hope he changes the instructions. Sometimes it takes a "dummy" to detect the obvious.