Will it hurt my fuel injector if I put it in the Ultrasonic cleaner at work? and how long should I leave it in?

Im trouble shooting the infamous "Stumbling Duke"

It ran good from the other side of town (10 miles) when I bought it. I ran it out of gas after I got it home moving it around the driveway. I thought the fuel pump died or the injector. ( it was late ) I ended up frying the ECM when i grounded the lo side of the injector while it was jumpered to the ECM power. I got another ECM from phonedawgz and it started and didn't mess with it much after that.

It had a pinhole leak in the fuel tank so I dropped it and found it was seriously rusty inside. So I replaced it. I also replaced the fuel filter.

I finally got to drive it around the block. It ran rough after the fuel tank R/R while cold. Its been sitting for at least 10 or 15 years so I figured its just cold blooded. I got on the gas pedal and cleared out the cobwebs (mildly) It seemed to run a little better after it warmed up.

Today its just cold blooded.

Any thoughts?

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Project Genisis Lo Budget 3800SC swap

88 Coupe under construction

Idle runs OK. Give it some throttle and it chugs. It wont start on first crank, second time it will usually.

I unplugged the map sensor and it seemed to idle not as good, but then the throttle response was a lot better. No stumble.
I swapped out MAP sensors with one from my 86 2.8L engine and disconnected the battery for a while. It seemed to run alot better. but still starts only on second crank.

Any one on the fuel injector?

It would be helpful to check the fuel pressure. I would try running injector cleaner through the tank before trying the ultrasonic cleaner

Okay thank you. I bought it from a guy who put a new fuel pump in it but I'm not trusting that it still good due to the rusty tank. I will check the fuel pressure.

[This message has been edited by hercimer01 (edited 10-17-2012).]

Do you hear the fuel pump prime? If the fuel pump isn't priming when you first put the key in the Run position, the fuel pump will not turn on until after the oil pressure reaches a certain level, which would make it usually not start on the first turn, but the second.

Yah, it primes when I first turn on the key, but it doesn't load up like the pressure is built up till the second time I turn the key on.

quote Originally posted by hercimer01: Welcome to the Forum!

Thanks, just getting into Fieros, have had too many 3rd gens, and had a 924 Turbo. Always just looking for a fun car to drive, and with the weight distribution of the Fiero, it is a pretty fun car to drive.

I have the MAP sensor swapped with my 2.8L one and it ran somewhat better.

I did a leak check on the EGR valve and it can't even hold enough vacuum to activate it. I think this explains why the cold idle jumps to 1,500 RPM.
Would it the cause the stumble when you goose it?

[This message has been edited by hercimer01 (edited 10-19-2012).]

If you had rust in your fuel tank,then Ide say your fuel filter is clogged.You can run a can of Berryman B-12 Chemtool into the tank (Autozone),and clean your injectors internally,with out pulling the injectors.Dont get any of that on your paint because this product will melt,fuel varnish and automotive paint,if left on long enough. I would allso inspect the air filter.Try jiggleing the engine wires,while the engine is running and see if you can find the source for the stumbleing.Check your engine at night, and see if you can see any Fireworks or stray sparks,jumping to the engine block..........Good Luck.

I have often thought a ultrasonic cleaner, even a small jewelry one, would be fine for injector cleaning. the trick is the solution used for cleaning. you dont want to strip the coating off the coil windings. that is basicly the ONLY thing to watch for. you can also try and get fancy, and dis-assemble the injectors for a more in depth cleaning. tho, I'd suggest practicing on a scrap part first.

but, in the end, a bottle of Techron thru the fuel system every 10k miles is my schedule.

There are so many things that could be wrong with it... these Dukes tend to have issues when they're allowed to sit for long periods of time, the least of which is usually the map sensor.

I've found that this stumbling problem is quite often caused by a clogged fuel tube that connects the fuel pump to the underside of the lid in the tank. I wish I had some pictures, but basically the rubber connection tube breaks down and restricts the amount of fuel that can get through. Lack of fuel will cause the stumbling issue.

I replaced the EGR valve. The diaphragm was definitely bad, but it runs no better now.

The Fuel filter is brand new.

I will change the hoses between the tank and the hard lines (fuel filter). I haven't looked to see what there are for rubber hoses after the hard lines, but, I will change those too if I can.

I still need to check the fuel pressure, I just haven't' had time yet.

I know the hose in the tank between the pump and sender is good and on tight.

EDIT, Thanks for the help so far,

[This message has been edited by hercimer01 (edited 10-20-2012).]

One little problem with the EGR is that it builds up a carbon like washer,where the EGR Tube attaches to the upper intake.I have no Idea how this carbon washer effects performance.

I went to Ogres' Cave and look into the L4 ignition and he covered it very well. The MAT sensor was very coked up.





I replaced and it accelerates tons better. I still need to get a good battery in it but i'm pretty sure that was it.

Thanks for the update. Hope it solved your problem.

The Mat sensor definitely made a big improvement, like 98%, but since then I also changed the fuel pressure regulator which completely solved the chug while goosing the throttle.
The car still will not start unless I cycle the key at least 2 or three times getting the fuel pressure up. I am going to change the fuel pump.

quote Originally posted by hercimer01: The car still will not start unless I cycle the key at least 2 or three times getting the fuel pressure up. I am going to change the fuel pump.

I changed the fuel pump and no change.
I changed the fuel injector O-rings and screens. Now it starts up on the first try. The injector wasn't fully seated.

Everything I did seems to have worked. I put a remote start on it and it starts on the third crank. It doesn't sound like its struggling to start at all. It does need to warm up until the idle drops down, I think that's normal or is it?

quote Originally posted by hercimer01: It does need to warm up until the idle drops down, I think that's normal or is it?

Yes, as far as I know. Every car I've ever driven (especially my Fiero) takes a little to warm up. Abby idles at 1k, but only after starting at 2k, a short while after 1.5k, and a quick run around the block it's 1k. She always idles at 1k in any gear other than neutral, no matter what. I believe you are just fine good work BTW!