Troubles after injector upgrade...

[Zoey]

Hi folks, if you have any ideas on how to help me out on this one I'd be forever grateful.

Here's the situation; Car was running fine with emissions chip and stock injectors. Got a Turbo Tweak chip for 42lb injectors, and 42lb injectors from Cottons pulled off the rail, and installed the new injectors. Instructions indicated to start at 46lbs of fuel with the vacuum line, off so I proceeded in that fashion. Can runs incredibly rich at idle, so much so that I'm getting raw fuel in the exhaust.

TT instructions say that the fuel pressure should come down to 5-8psi with the vacuum line on. It does not go down that far. I tested the vacuum at that point, and its 18lbs so I don't think that the vacuum is bad or low. The fuel pressure regulator was working before with the smaller injectors, and no fuel is leaking from the rail.

When the car actually spools up it seems to run strong but rich, but it is certainly not right at the moment. It has an upgraded fuel pump, and an adjustable fuel pressure regulator, both of which were working correctly before the new injectors so I don't think the problem lies there. Adjusting the fuel pressure as low as it will go does not fix the problem. Putting the emissions chip back in changes the exhaust note on the car but doesn't change the fuel problem.

It seems to be something wrong with the injectors themselves. Any ideas? The only thing I could think is that they are leaking fuel straight through them. I haven't taken them off to test them yet. That would be the next step.

-Zoey

 

[melrob94]

Just did the same setup. Back the fuel down a couple of PSI. It should drop about 5psi when you re attach the vacuum, not drop to 5 psi. Is it raw fuel coming out the tail pipe or condensation? My car idles rich, I have to pull it out of the garage or the wife complains of fumes in the house.

 

[Zoey]

Ok that makes sense, it does drop 5 psi, the sentence must be an ambiguous parse in the instructions. It seemed wrong because it never dropped *to* 5psi before, but it did drop 5psi. So that makes sense, but it still has raw fuel in the exhaust, and doesn't run right. So much raw fuel that it leaks out of the turbo clamps on my header, and resulted in a small fire after a test run. Luckily I was prepared with an extinguisher, and gave it a quick poof.

Hmmm it runs so rich that if I stick my head into the engine bay to take a look I pretty much instantly get a headache, and it drips out of the turbo clamps creating a pool of gas on the concrete.

-Zoey

 

[melrob94]

You definately have a problem. Does the fuel rail hold pressure after shutting off the ignition, or does it bleed off quickly? Mine will take a couple of hours to bleed down to zero on the FP gauge. Just trying to give you somewhere to start. There are others here that will probably be more help. I wouldn't run the car with the possibility of fire. Maybe put the old injectors back in and see if it is the injectors. Re check your fuel lines into the rail and Regulator, if you removed them to install the injectors.

 

[Zoey]

The rail does take time to bleed down, but it used to take more time than it does now. It used to never bleed down, so that's why I kind of suspected that the injectors were passing gas through them when they shouldn't be. I'll probably put the old injectors back in to see what happens. They are a bit grotty though, so I'll probably have to find some new rubber o-rings for them. Bleah.

-Zoey

 

[melrob94]

Check you plugs, you might be able to narrow it down to one injector, if that is the problem. A rich cylinder will definately show up on your plugs.

 

[Chuck Leeper]

Whats the part number on the injs??
Cycle the key on and off a couple times, without starting the engine. Pull the plugs, any wet??
If so, you may have an inj that are stuck open.

 

[breiter]

Any chance you two or more of the injector connectors are plugged into the wrong injectors? May want to verify the chip is programmed right? My car runs a little rich but by choice. Raw fuel smell under the hood is not normal. Did you replace and lubricate the o-rings? You can buy them at any auto parts store.

 

[Zoey]

I don't think the injectors are plugged in wrong, the harness doesn't seem to reach to the incorrect injectors. Is there a way I can tell for sure? The new injectors have new oring seals and I lubed them before putting them in. I'll check the plugs and see if I can isolate the problem.

-Zoey

 

[breiter]

If you did not cut the tie wraps that hold the harness to the fuel rail then plugs should only reach its injector. Did the injectors seat all the way? I am sure they did when you bolted the fuel rail back to the intake. You should be to twist the injector with a little effort. If no fuel is leaking from the rail or intake at the injector then don't disturb it.

Stuck injector? Chip programmed wrong? With the car off, turn the key on (don't start) and listen for the fuel pump come on and then turn off (not the key - the pump). If there is a stuck injector it should cause the pump to come back as the pressure bleeds off. Watch the gage and do you smell raw gas? If the pump comes back on (say within a minute or so) then you should be able to unplug the injectors individually until the pump stops coming on (within your timed amount). That should be the bad injector. Of course I have never done this but it is something I would try.

Raw fuel coming out from around the turbo clamps has me puzzled. There should only possibly be fuel on the exhaust side but there are no clamps. Nothing should be leaking around the clamps... Please explain.

 

[Zoey]

The car has a header on it with turbo clamps connecting the cross over pipe. Because they are turbo clamps... they leak a bit.

Anyway, the injectors are numbered 2277 and 01D030B on each one.

The tie wraps were somewhat old and grotty so I did remove them, but the leads still obviously only go to the correct place. If there is a way to check which lead goes where I can obviously do that.

I took the injectors out over lunch, and I tested each one with compressed air from the rail side. 90lbs of air did not pass through them. Electrically they all had a pole to pole resistance of 16.4 ohms 16.6 ohms. 5 of them had a 16.5ish value and one was 16.6ish.
Yes the injectors did seat down correctly.

I also checked the plugs and two of them were more obviously wet than the others.

I'm going to see if I can find a tech center in sac that can test the injectors for me.

-Zoey

 

[Chuck Leeper]

"If there is a stuck injector it should cause the pump to come back as the pressure bleeds off. Watch the gage and do you smell raw gas? If the pump comes back on (say within a minute or so) then you should be able to unplug the injectors individually until the pump stops coming on (within your timed amount). "

Nope. The pump will not cycle due to psi drop.
Once key is on, the ecm times the initial prime sequence, and then times out. It will not reprime until key has been turned off, and the prime cycle reset...
There is no ecm input from fuel pressure.

 

[darkred87T]

Have you tried contacting who you bought it from? Maybe the chip was accidently programmed for a bigger injector like 60s?

When I had stock injectors in my car, I tried a chip that was programmed for 60lb/hr injectors and it did the same thing you are describing.

 

[Zoey]

So I tested the injectors with compressed air at lunch time and they didn't leak in the off state, which caused me to doubt our leaky injector theory, but I figured we should still get them tested.

So surfed around on the web for a place in Sac to test my injectors, and I called a couple of places which advertised for diesel injectors with no luck. I rung Dr. Injector which is up at 11395 Pyrites way off Sunrise/Coloma and they said they could do it for $10.50 an injector, and that they were open until 5:00.

I got off work at 4:00, and we braved the Sunrise traffic and got there about 4:20. Jake Rosen very kindly put my brand new 42# injectors on his machine, and we took a look. They didn't pass any fuel when off (which I had confirmed at home with my air compressor), but as soon as he started the test it was obvious that one of the injectors leaked a good deal of raw gas every time it received a pulse. Over a 30 second test it leaked 20ml more gas at idle than the other injectors. Basically as it was turning on, and as it was turning off, it would dribble out liquid gas instead of misting.

So the problem is found. I'm really impressed with Jake's friendly service. He put the injectors on the machine at the end of the day, and didn't end up charging me for it. He suggested that I get in touch with the seller, (Jack Cotton) and see if we can get this squared up. He also said that he could clean the injectors ultrasonically but because the injectors are new, it is unlikely that cleaning them would solve the problem. This was a total Macy's Santa move because I was ready to pay for a cleaning.

I'll probably take the GN up there as soon as I get a new injector and see if Jake can do up the front end for me. (Our GN has bad bushings on the front suspension.)

Anyway, thanks to Jake Rosen of Dr. Injector the injector problem is identified. Now I just need to get a replacement 42#, and I should be set.

-Zoey

 

[Zoey]

All is well, I got an email response back from Jack Cotton from my email yesterday and talked to him on the phone today, he said send the injector back and he'll send one right out. YAY!

-Zoey

 

[breiter]

Glad you got it figured out. Sorry my thought for testing was wrong. Thanks Chuck Leeper for explaining that the pump shuts off after being primed. I should have known that.

 

[Chuck Leeper]

All's good..

Glad you got it figured out. Sorry my thought for testing was wrong. Thanks Chuck Leeper for explaining that the pump shuts off after being primed. I should have known that.

problem corrected.!
In the FWIW dept:
Sometimes, if an injector has some extended shelf time, the lube that was in it, will gell some, and make the inj sticky. A rap on a wood block on the inlet end may correct this...
I always advise that if injs are to be stored after use, they should have the fuel shaken out, a bit of lube, such as WD40, or 3 in 1, added. They should be capped, and put in sealed bags. An additional help, is to put them in a Tupperware bowl, and "burb" the lid. Anything that prevents intro of air will help.
Leaving injs out is a quick way to ruin them. Many times I get them and they are locked up, and cannot be resurrected.
Most all injs are not stainless, thus they WILL rust up.. FATAL!
Lastly I recommend you not have injs cleaned until you are ready to install and start the engine....

 

[wallyp]

Great advise, go to know, thanks :

 

[Zoey]

Troubles resolved!

Excellent news, we got the replacement injector from Jack Cotton Friday, and got the car back together on Saturday. Much better! It still runs a little rich at idle, but I think its just a matter of tuning at this point.

With the TT chip for 42# injectors the car runs very smoothly, and the power is very strong.

More tuning to come.

-Zoey

 

[melrob94]

Glad to here you got it figured out.