Hi everybody,

 

I expirience hot-start problems after injector cleaning i made few days ago.

 

The cleanig method was DIY with carb cleaner. I soaked the injectors in a small bath of carb cleaner and ran them with a special injector machine that opens them without damaging them (give them short pulses).

 

After that the car run perfect and i feel the torque increased.

 

The problem is that after the car sit's for more then 10-15 minutes, it has difficults on starting (long starter). O-rings are in a fine shape, no leaks outside. Before the cleaning everything was 100% perfect with no hot-start problems, that why i know that the problem is the injectors.

 

I suspect the at least one injector stays alittle bit open and floods the engine. I disassemble the injectors rail and i feel that from the bottom of the rail there is a little bit of fuel. I cant see exactly if the o-rings are leaking or the injectors are leaking, although i know that the o-rings are in a-fine shape. Few days before the cleaning I disassemble the injectors and assembled again with no leaks or hot-start problems. At all the times i've used silicone spray on the o-rings to fit them perfectly.

 

Few days later i made a 2nd clean with mixture of 50% gas and 50% carb cleaner, All that through a small tank with external fuel pump (like dialysis or fuel injector cleaning with a special machine). The 2nd clean made a huge diffrence and the car starts alot faster, but still not like before.

 

I'd like to hear from you'r expirience and knowledge how to clean them perfectly to solve this little problem.

 

Thanks.

Hi everybody,

 

I expirience hot-start problems after injector cleaning i made few days ago.

 

The cleanig method was DIY with carb cleaner. I soaked the injectors in a small bath of carb cleaner and ran them with a special injector machine that opens them without damaging them (give them short pulses).

 

After that the car run perfect and i feel the torque increased.

 

The problem is that after the car sit's for more then 10-15 minutes, it has difficults on starting (long starter). O-rings are in a fine shape, no leaks outside. Before the cleaning everything was 100% perfect with no hot-start problems, that why i know that the problem is the injectors.

 

I suspect the at least one injector stays alittle bit open and floods the engine. I disassemble the injectors rail and i feel that from the bottom of the rail there is a little bit of fuel. I cant see exactly if the o-rings are leaking or the injectors are leaking, although i know that the o-rings are in a-fine shape. Few days before the cleaning I disassemble the injectors and assembled again with no leaks or hot-start problems. At all the times i've used silicone spray on the o-rings to fit them perfectly.

 

Few days later i made a 2nd clean with mixture of 50% gas and 50% carb cleaner, All that through a small tank with external fuel pump (like dialysis or fuel injector cleaning with a special machine). The 2nd clean made a huge diffrence and the car starts alot faster, but still not like before.

 

I'd like to hear from you'r expirience and knowledge how to clean them perfectly to solve this little problem.

 

Thanks.

 

Sounds like a faulty coolant temperature sensor - the symptoms of fine start when cold but hard start when warm are classic.

Forgot to mention, neither cold starts are OK.

 

And an update: cleaned the injectors ultrasonicly today. After that, for about 1-2 times, startup was perfect - and from that point - worse again.

 

Next step: replacing the O-rings of the injectors, especially the bottom o-rings (the upper o-rings are not leaking).

I would not have a lot of faith in this suggestion, but if you have not done it , I think I would undo the battery for around 30 min. to reset the computer, it may help and is very little work.

Forgot to mention, neither cold starts are OK.

 

And an update: cleaned the injectors ultrasonicly today. After that, for about 1-2 times, startup was perfect - and from that point - worse again.

 

Next step: replacing the O-rings of the injectors, especially the bottom o-rings (the upper o-rings are not leaking).

It may be time to focus on fuel pump pressure and pressure regulator. maybe a leak is allowing the rails to de-pressurize or something?

 

If you immediately restart after turning the engine off and it starts OK - I'd suspect fuel pressure issues.

 

I dunno.

I was a few times sent astray by a false cause-effect relation*. It's very tempting to conclude from one fact following the other that the former is the cause of the latter. Often true, but by no means always.

So there's a strong possibility that your hard start situation is injector related, but dont rule out a coincidental failure of the temp sensor.

 

*One example: when I was driving the Loyale, I stopped the engine inside an atomatic car wash and was unable to restart. I concluded that the problem was humidity related and I replaced the disty cap and rotor, and the plug wires. In fact, the problem was that I was trying to start the engine while it was still hot while the temp sensor was telling the ECU that the engine was cold = flooding.

I would not have a lot of faith in this suggestion, but if you have not done it , I think I would undo the battery for around 30 min. to reset the computer, it may help and is very little work.

 

Already done that few days ago - didnt help.

 

The problem started the day the injector's been cleaned and the suspects are the injectors or their o-rings.

Right now, after the injector's has been ultrasonicly cleaned - the only suspects are the o-rings.

 

There is a very, but very (!), small possibility that the problem is in one of the sensors or somthing else.

I will keep updating you untill the problem solved. Right now there is a small problem of getting new o-rings in my area so tomorrow i'm going to try to replace my o-rings with other o-rings that are in better shape.

In about a week i'll get *new* o-rings, hopefully sooner.

Injectors aren't just a hole like a carb jet, they are a bit more complex, and my money is betting on one or more of them being Tango Uniform.

Injectors aren't just a hole like a carb jet, they are a bit more complex, and my money is betting on one or more of them being Tango Uniform.

So, are there any advices what to do in that case ?

So, are there any advices what to do in that case ?

 

I'm not familiar with the internals of an injector, but I wonder if it might have something to do with the ultrasonic cleaning? Would the higher frequency of the ultrasonic cleaning have some negative effect on the injector?

Mike

I'm not familiar with the internals of an injector, but I wonder if it might have something to do with the ultrasonic cleaning? Would the higher frequency of the ultrasonic cleaning have some negative effect on the injector?

Mike

 

The problem 1st occurred after the injector's soaked in the small bath of carb cleaner. The injector's connected to a special desinged machine that activates the injectors like they were on the car.

 

The ultrasonic cleaning was tried after the problem occured and solution was necessary. The ultrasonic cleaning did not solve the problem.

 

As i see the problem now, unfortunately i almost sure that one of the injectors, or even more, are leaking. When the problem will be solved i promise to update the exact reason and solution. For now, i'll be glad to hear some advices for more checks.

 

BTW: I would like to make a little correction for this theard title, it should be "hard start after injector cleaning".

 

Thanks.

Update:

 

The vehicle tested with a scanner today. The coolant temp sensor is working perfectly and all the other sensor are working perfectly according to the FSM (meaning that the injection time is correct, TPS well adjusted and also the ISC valve is well adjusted - there's nothing to touch).

 

Except that we also tested the fuel pressure of all the system and made another few test's for specific sections (from the fuel pump till fuel filter _and_ from the fuel filter till the end of the system - exactly after the fuel pressure regulator - which is the injectors section). The second test made with the fuel return-line clogged.

 

The results shows that the section from the fuel pump till the fuel filter is perfect and it almost doesnt losing any pressure. The second test (injector section) shows a pretty fast depressurize, meaning that there is a leak in this section. Now there are 2 possiable ways to leak; 1st is from the o-rings, 2nd is the injector(s).

 

Any suggestion's or idea's will be thankful.

 

More updates will come as soon as will be any...

Update:

 

The vehicle tested with a scanner today. The coolant temp sensor is working perfectly and all the other sensor are working perfectly according to the FSM (meaning that the injection time is correct, TPS well adjusted and also the ISC valve is well adjusted - there's nothing to touch).

 

Except that we also tested the fuel pressure of all the system and made another few test's for specific sections (from the fuel pump till fuel filter _and_ from the fuel filter till the end of the system - exactly after the fuel pressure regulator - which is the injectors section). The second test made with the fuel return-line clogged.

 

The results shows that the section from the fuel pump till the fuel filter is perfect and it almost doesnt losing any pressure. The second test (injector section) shows a pretty fast depressurize, meaning that there is a leak in this section. Now there are 2 possiable ways to leak; 1st is from the o-rings, 2nd is the injector(s).

 

Any suggestion's or idea's will be thankful.

 

More updates will come as soon as will be any...

 

makes sense to me.

I didn't reread the thread - have u looked for a wet sparkplug after it sits for a while? maybe , if a single plug is wet with fuel, it will pinpoint the problem injector. Also, isn't there a regulator on the end of the the fuel rail? Could it have a leak?

 

good luck and thanx for the update.

 

Carl

makes sense to me.

I didn't reread the thread - have u looked for a wet sparkplug after it sits for a while? maybe , if a single plug is wet with fuel, it will pinpoint the problem injector. Also, isn't there a regulator on the end of the the fuel rail? Could it have a leak?

good luck and thanx for the update.

Carl

 

Thanks, Carl.

 

Another update from today's tests:

Took out (carfully) 2 screws that holds the right fuel rail to the engine. Dryed everything with papertowl and pressurized the system (moved the key to "ON" position few times, hearing the fuel pump work for 2 seconds each time).

 

By using a small mirror i checked the down side of the rail - and i could see fuel leaking slowly over the plastic cap around the nozzle of the injectors.

 

For now, the main suspects are the O-rings. I must find as soon as possible new o-rings (only 4 needed) and see if the problem exists.... Otherwise, i will have to replace the injectors.

 

More updates will come...

Unfortunately, I'm not real familiar with the fuel injection system, or stereo for that matter, and where the o-rings would come into play.

 

When we have a problem on one of our C130's, my initial check is to find out what was done last to the system that's malfunctioning.

 

In your case, the problem didn't exist until you cleaned the injectors. So I have to put my money on the fact that one or more were damaged.

 

I had a problem with a Ford Toreass head gasket, and the water ruined one of the injectors. The parts dept gave me a new one, but it wasn't exactly the right one and it still ran crappy until I installed the right one.

 

The spark plugs should be blackened on the cylinders being affected.

Last update:

 

I replaced few days ago the injectors (all 4 of them); problem solved.

 

Next time you think about taking out the injectors for a clean, think twice and clean them on the car.

 

Itzik.

i think you made your injectors very very angry. fuel injectors on their face value are not that complicated, but once you realize the internal tolerances, it doesnt take much to screw them up. COld starts are fine because a little extra fuel isnt a bad thing when cold, but is when hot.

Since i cant see the car, get a scanner and see whats happening. i think you may have to get new injectors. You have only partially cleaned the injectors with the carb cleaner, then the ultrasound made it worse. Ultrasound can also do damage if you dont know what your doing. Ultrasound + aluminum or electrical parts is very bad.

http://www.pprep.com/fuel_injector_work.htm

 

The only true way now to test is flow test, dont even think of doing that yourself. Fire and explosion a bad bad thing, along with gasoline peircing your skin.

 

nipper

i think you may have to get new injectors.

 

As i said before, i already changed the injectors (with injectors i bought from a "wrack-yard"). After everything was set on the car (and the car was starting and driving *great*) i passed them an "on-car" cleaning procedure with BG products - and thats it

 

For now, the car is driving excellent and starting great in all situations.

 

Itzik

As i said before, i already changed the injectors (with injectors i bought from a "wrack-yard"). After everything was set on the car (and the car was starting and driving *great*) i passed them an "on-car" cleaning procedure with BG products - and thats it

 

For now, the car is driving excellent and starting great in all situations.

 

Itzik

good, see i was right you needed replacement injectors so tthhrpppttttt

 

nipper

Hello everyone

 

I also read that thread a few weeks ago becouse I have the same hard start problem when the car was hot (cleaning wasnt a reason-problem was about two years old) . I replaced all 4 injectors and I solved problem

And now I am asking you guys if there is any chance to test which of the old 4 injecotrs was faulty before I give back old injectors to friend (I think the one is problem and not 4 of them).

 

My friend also have that problem and I think if there is any chance to test at home which injector is faulty with random disconnecting the injector electric. And see if car will start faster without the faulty injector which have chance to fload the engine.

Hello everyone

 

I also read that thread a few weeks ago becouse I have the same hard start problem when the car was hot (cleaning wasnt a reason-problem was about two years old) . I replaced all 4 injectors and I solved problem

And now I am asking you guys if there is any chance to test which of the old 4 injecotrs was faulty before I give back old injectors to friend (I think the one is problem and not 4 of them).

 

My friend also have that problem and I think if there is any chance to test at home which injector is faulty with random disconnecting the injector electric. And see if car will start faster without the faulty injector which have chance to fload the engine.

 

There really is no method to bech test injectors (at home) to see which one is worn. You can test coil resistance, but that wont address the issue. DO NOT PRESSURIZE THEM AND BENCH TEST!!!!!!!!!!!!!!!!

 

This can result in all sorts of ugly things happening if you dont know what your doing. We dont want anyone here winning a darwin award.

 

nipper

I soaked the injectors in a small bath of carb cleaner and ran them with a special injector machine that opens them without damaging them (give them short pulses).

 

So what was the name of this "special injector machine" that fried your injectors? Did it run 12v to them or something?