Injector problems?

[CJ-8_Jim]

Background:
Originally with this new stroker engine (and Hesco 1995 OBD I MPI), I had bought from eBay InjectorPlanet Bosch Fuel Injectors 0280155849 (rated 24.5lb/hr @ 43.5psi same as Ford XF1E-A5B), but I couldn't get the engine originally to catch... at first I was flooding the engine, then it appeared I was starving the engine.

So I put the original 1995 Hesco MPI injectors with my adjustable fuel pressure regulator cranked up as high as it would go.... no luck.
Then I put a new CPS on and it started right away with the 1995 Hesco MPI injectors and the Hesco Adjustable Fuel Pressure Regulator cranked up all the way.

This has been working for about the first 200 miles on the new engine.

Then the new fuel pump started to whine loudly and surge/de-surge a bit yesterday.

- So tonight, I thought I'd experiment with Bosch Fuel Injector 0280155849 injectors I tried earlier.
- It ran rough at first for a few seconds then evened out some, but then at idle, the engine would race at idle at 2200 rpm Throttle was very touchy.
- Then I drove it around the block (2200 rpm idle or 1400-1500 rpm idling in 1st gear) thinking the computer needed more time to learn, but that didn't help.
- I brought it back and saw I had code 52 (bad O2 or too high fuel pressure at rail). So I disconnected the battery for a few minutes to clear the computer codes thinking it needed to re-learn from OEM settings.
- Then drove it around the block again.... same 2200 rpm idle (or 1400-1500 rpm idling in 1st gear) and then the MIL light stayed on.
- Came back and lowered the fuel pressure a few turns (for some reason my fuel rail schrader valve has stopped working) and now it won't start.
- Cranked it back up again and still no start.
- I have spark going to the distributor.

So I tried testing fuel: I get about 1/8+ cup of fuel (about 3 tablespoons) at fuel supply line when disconnected from fuel rail (with one Key On Engine Off).

I'm going to try tracking down a fuel pressure tester tomorrow.

Question: Can fuel injectors be finicky and alternate between being stuck open and stuck closed?
Is it possible I got one or more bad injectors?
Other thoughts?

[CJ-8_Jim]

Solved the no-start issue... I had one bad newly reman Bosch Fuel Injector 0280155849 from Injector Planet.

I discovered this by testing the Bosch 0280155849 injectors with a sandwich bag on each and jumped the fuel pump -- sure enough one leaked a lot -- 1/4 cup of fuel leaked out in to the plastic bag with the pump running.
I suspect that was the reason why I had to have the AFPR cranked down so much (high fuel pressure) to get the engine to run (I needed to do that so the other injectors had enough fuel).


New Problem:
1) I swapped the bad injector out for another that tested good (I bought an 8-pack of injectors) and installed the HESCO AFR set at 44 psi.
Turned it on and at idle the engine raced up to 3000 RPM at 44psi at the rail. It wouldn't drop so I turned it off after 2 seconds. No codes.

2) Disconnected/reconnected battery to clear computer. Lowered the AFR pressure and started it up... engine raced to idling at 3000 RPM, but now fuel pressure is 38 psi at the rail. Turned it off after 1 second. No Codes.

3) Disconnected/reconnected battery to clear computer. Lowered the AFR pressure and started it up... again engine raced at idling, but now at 3500 RPM, but now fuel pressure is 30 psi at the rail. Turned it off after 1 second. No Codes.

4) Disconnected/reconnected battery to clear computer. Lowered the AFR pressure and started it up... again engine raced at idling, but now at 4000 RPM, but now fuel pressure is 26 psi at the rail. Turned it off after 1 second. No Codes.

5) Dug out the old original non-adjustable FPR that came with the HESCO MPI kit back when I had a 258. Put it on, check the pressure setting using an air hose on the fuel rail and the fuel pressure tester on the fuel rail: 39 psi as it should be.
Tried starting it, but it would not start... it sounded like it maybe wanted to catch but I'm assuming it was starved of fuel.

This no-start with non-adjustable fuel regulator and new Bosch Fuel Injectors 0280155849 was a similar situation early on when I had the enw engine. I worked around that problem at that time by putting the old HESCO MPI Injectors on (brown ones) and using the AFR at about 45-50 PSI (can't remember).

This setup (HESCO MPI kit brown MPI Injectors with AFR tightened down a bit -- higher PSI) is what I was running before last night when I thought I'd try again the newly reman Bosch 0280155849 injectors.

I need ideas.

Maybe I need new injectors.... and different ones taht are not the Bosch 0280155849?

[Cheromaniac]

With the engine racing up to a 3000+rpm idle, I suspect you either have a vacuum leak or the butterfly inside the throttle body isn't closing properly.
Chances are the solution is very simple.

[CJ-8_Jim]

With the engine racing up to a 3000+rpm idle, I suspect you either have a vacuum leak or the butterfly inside the throttle body isn't closing properly.
Chances are the solution is very simple.

Bingo!

Cleaned the linkage and butterfly so it closes all the way and it idles correctly now.
In my defense, I had 4 hrs sleep the night before due to a sick child.

Come to think of it, maybe dirty butterfly was compensating in part for the insanely leaking newly reman injector.
Who knows, it's running now.

But now the loan-a-tool fuel injector pressure gauge doesn't register any readings and shows 0 psi. LOL!
It does say "Made in China".

Thanks so much Cheromaniac.