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Leaking Fuel Injector Symptom?

Well then you'll be wanting to delete the resistor pack to use those.

Here's a link if you're not up on how to do that.

Hope that fixes it for you. But if your FPR is fuctional, doesn't seem like much else can be causing that...
 
lummert said:
Bosch 4 hole injectors in a late 80s to early 90s Pontiac Bonneville SSE Supercharged.
Click to expand...

Injector location in this 3800 engine is inline with intake port, like Volvo, so the spray pattern should be the same. I'd test the spray pattern before installing, unless these came from a recently retired vehicle.

26-completedEngine.jpg
 
The Ford injectors are in. I checked for leaking injectors after pulling the fuel rail. Not one drop of fuel from the injectors with the fuel pump relay jumped. I then checked for leaking with the 3.8 Bar fuel pressure regulator, still no leaks.

I installed the Ford Injectors and adjusted the AMM. The AMM adjustment ended up being nearly the same as with the stock injectors. Car runs smoother and has more seat of the pants feel.

Next thing is get a fuel pump check-valve. The used check-valve I recently installed has to be bad.

I bypassed the resistor pack, but a permanent solution for that is needed.
 
If I had known that Bosch 4-hole 0 280 150 934 injectors would cause my 88 765 Turbo to get 25 mpg I would have done this swap years ago.

Don't everyone run out and hunt these injectors at the same time.

Hint: they were OE in Buick V6 3.8L V6 Supercharged used in 91-95 Buick Park Avenue, 1995 Buick Riviera, 92-95 Olds Ninety Eight, and 92-95 Pontiac Bonneville.
 
After getting 25 mpg on a short trip from Jay County to Fort Wayne and back home and a couple of days driving around town I thought I'd check the base Idle setting using my homemade LED tool. After a trip across town and back I connected the LED tool and found that LH2.2 had been running in open loop (LED on and not blinking) and was running too rich.

I adjusted the AMM until the LED started flashing. I checked the ohms across the pins of the AMM and found the setting to be 385 ohms. The setting with the old OE injectors was 629 ohms. 385 ohms is what the initial setting should be.
 
After getting the crankcase breather system working as good as possible and no longer smelling burning oil vapors, I noticed that I can smell raw fuel when shutting off the car.

Been having a problem with the fuel system not holding any pressure after shutting down the engine. Got under the car with a 4 cell flashlight tonight with the engine running. One or both of the copper washers at the outlet of the fuel filter are seeping fuel.

This leak would explain the system not holding pressure after engine shutdown.
 
This morning after a short trip uptown I got down on a big sheet of cardboard and looked at the suspect fuel filter outlet seals. The leak was worse than I thought.

I used a propane torch to anneal several 12mm copper washers that I have on hand, then removed the banjo bolt and replaced the seals.

No more leak. The fuel pressure still leaks off, but not as fast as before.
 
After having much difficulty adjust the fuel mixture I started some research on fuel injectors. Bosch 0 280 150 934 injector is from supercharged 3.8L Buick V6. Buick uses 3 Bar FPR. These are what I have installed. Bosch 0 280 150 945 are Ford Racing red top injectors used in supercharged 3.8L used in Thunderbird SC. These 2 injectors have identical flow specs at 3 Bar.

The target psi for the Ford Racing red top injector is 39.15 psi. So i used an injector flow rate calculator and determined that The Ford Redtop injector at 39.15 psi is comparable to the original 0 280 150 357 injector at 43.5 psi. The improvement is the 4 hole injector.

So I swapped in the best of 2 BMW 320i 2.5 Bar fuel pressure regulators from my parts stash and checked the fuel pressure at the rail. It tested at 2.7 Bar (39.15 psi). I then got out the LED tester and adjusted the baseline idle mixture setting.

One note: when removing the old fuel pressure regulator I pulled the vacuum hose first then the return hose. When I pulled the return hose there was vacuum at the FPR return nipple. The engine had cooled for about an hour before doing this swap. I've never seen vacuum at the return nipple before even on a warm engine. Makes me think the FPR was defective.
 
After much tail chasing I found a nickel sized hole in the hose that runs between the intercooler pipe and the throttle body. Replaced hose. Re-installed 3 Bar fuel pressure regulator (was running 2.5 Bar FPR from BMW). Car seems to be running better.
 
Today I switched back to the 2.5 Bar FPR. The car (88 765 with B230FT and LH 2.2) was running too rich at 3 Bar even though the AMM was adjusted correctly.

Looking up the injectors I'm running: Bosch white top 0 280 150 934 from Supercharged Buick 3.8 liter V6 found in Pontiac Bonneville or 90-93 supercharged Ford 3.8 liter V6 found in Thunderbird and Cougar.

0 280 150 934 white tops are the same spec as 0 280 150 945 Ford Racing Red Top Injectors.

These 0 280 150 934/ 0 280 150 945 injectors are rated at 39.15 psi or 2.5 Bar.
28.55 lb/hr
300.1 cc/min
215.8 grams
39.15 psi - 2.5 bar

O 280 150 357 stock injectors:
28.6 lb/hr
300.6 cc/min
216.2 grams
43.5 psi 0 3 bar

So, the 0 280 150 934/945 @ 2.5 Bar is = to 0 280 150 357 injectors @ 3.0 Bar

0 280 150 934/945 injectors are 4 hole cross stream.

I found mention of 0 280 150 934 36# white top injector being OE in 96-03 GM L67 Supercharged3800 Series II. This leads me to think 30# @ 39.15 psi = 36# @ 43.5 psi.
 
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lummert said:
...
One note: when removing the old fuel pressure regulator I pulled the vacuum hose first then the return hose. When I pulled the return hose there was vacuum at the FPR return nipple. The engine had cooled for about an hour before doing this swap. I've never seen vacuum at the return nipple before even on a warm engine. Makes me think the FPR was defective.
Click to expand...

Only thing to make you think there was vacuum there was the vacuum created as the return pipe drained its head of fuel back to the tank. Not vacuum on the FPR return port, but vacuum on the hose you took off of it. Normal.
 
cleanflametrap said:
vacuum created as the return pipe drained its head of fuel back to the tank.
Click to expand...

I've bought two non-OEM FPRs, and both will leak down, after engine is shut-off. I assume this was a design feature to reduce standing pressure on injector side.

Both FPRs work just fine on both of my running Volvos. I have no idea if a government agency is responsible, or if this manufacture does it for some reason. Each FPR was bought about a year apart in time, so I must assume this was a design spec.

Not a bad idea, if an injector was leaking down.
 
84B23F said:
I've bought two non-OEM FPRs
Click to expand...

I understand. I just replaced one using a Bosch I'd put on the shelf 12 years ago for $42. Went to re-stock and my jaw dropped at the new price. But yes, I've heard no one can make them as well as Bosch, and even theirs have a reputation for an occasional out-of-box failure.

It should hold pressure. Spec requires it for warm starts of course.
 
Noticed that the cold start with 2.5 bar fuel pressure regulator the engine acted like not enough fuel for cold enrichment, but ran fine after warm up. So I tried a 3.8 bar (55 psi) FPR from a Turbo Dodge. Engine seems to like the 4-hole injectors at the higher fuel pressure. AMM adjustment was still within adjustment range.

Found some specs for the Supercharged Buick V6 white top injectors @ 3 bar:

308 cc/min @ 3 bar

Or:

346.33 cc/min or 32.05 lbs/hr @ 3.8 bar

These 3.8 bar specs are about equal to the 0 280 150 804 (B230FT w/ LH 2.4) injectors at 3 bar.
 
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I noticed what looked like oil on the end and black oily residue inside of the tail pipe. I also noticed billowing smoke out the tail pipe when driving at highway speed today. Then I remembered noticing something similar happening the last time I tried running the 3.8 bar fpr. I figured too much fuel was washing down the cylinder walls.

I swapped back to the 3 bar fpr. Tomorrow I'm going 50 miles out of town for an appointment. This will give a change to check if the car is still billowing smoke.
 
Yesterdays out of town trip with 3 bar fpr resulted in exhaust smoke and what looked like oil/gas spots all over the right rear of my wagon kind of like what a person would get when driving a diesel car. When I got home I swapped the fpr from 3 bar back to 2.5 bar. Only detectable oil smoke at this time is due to leaking valve seals.

Could the Bosch fuel injectors meant for supercharged Buick/Ford 3.8 V6 just be that sensitive to the rail pressure?
 
lummert said:
Buick/Ford 3.8 V6 just be that sensitive to the rail pressure?
Click to expand...

Injectors have a specific spray pattern at a given pressure, and they should be matched to their design rail pressure. Pulse width time vs amount sprayed is another consideration.

All the ECU is doing is grounding out the injector.

One needs the tech specs, or good bench tested specs, which most OEMs don't provide. Bosch Motorsports provides these specific details.

I'm using a newer OEM injector on my 240/940s, and they are a pinch rich in open loop. Since I drive many miles per stops, this is not an issue. But, if I lived in a city doing short drives, that extra fuel "washing" down cylinder walls would dilute the oil.

One reason why these EFI engines last longer is that there is little fuel getting into oil. In carburetor days, this was common. Fuel/Air mixture was rich on closet cylinders to carb, and about right fuel/air on outer cylinders. It had to be designed this way, otherwise, closet cylinders would run lean.
 
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