Gentlemen,

Its an honor to be here and I am sure someone had this issue already and might be able to help me.

First of all my car has a little background and symptoms, I will try to get into some details to give you a clear picture.

So recently I bought this 91 Firebird with a 3.1L V6. It has been parked in a car lot for 16 years!!! without moving it or starting it. I bought it as it has no any modifications, full factory used parts were in it with only 55K Miles in it.

I took it home and started the restoration. I managed to get it running after some part replacements. I started with the fuel pump... it was in a pretty bad shape... Its filter was consumed by the remaining fuel in it and had to be replaced. The gas tank was cleared out, fuel filter was changed and with the original Injectors it was running nicely but after some time it began to "lose" some cylinders from firing and it stalled. Therefore I decided to get this baby some fresh stuff... So I have taken out the injectors and get them cleared, new spark plugs, spark cables, distributor and rotor have been installed. After the injector clearing it has been found that 1 "was not good". The tech guy could not really specify it any better, I guess the fuel flow was not good enough... anyways I got a "new" factory refurbished injector and installed them all last week. The car was running nice like charm without any issues with good and fast reaction for quick acceleration and so on. However It began to act like it did before and yesterday when I was parking out from my garage as I put it into reverse - (just to mention the car was not moving since the new injectors were in, but it has been started 3 times a week for about 15 minutes ) - one of my cylinders lost spark/fire and as I headed out I have lost another 2... I kept it running however slowly I have lost the 4th and then the car stopped. This happened exactly before I installed all those things I have mentioned and cleared the injectors. As I took out a spark plug it was all black (ACDelco Rapidfire) and covered with fuel... I had no time yet to take them out but I am more then sure that its the same and all are covered with fuel again...

Sorry for the long explanation, I just wanted to be sure I mention the necessary stuff.

So my guesses are:

- the old Injectors the remaining 5 which are original, are still not in a good shape and might leak and let too much of gas in...

- Maybe the remaining fuel tube under the car is full with some junk from the old fuel and it get into the injectors and make them stuck and leak fuel.

- a sensor might be sending false values and get my computer to mess up the right fuel/air ratio

- OR some serious issue within the block?

My plan is, to get the whole fuel pipe line replaced which comes from the tank to the hood and get 5 other injectors to rule the old ones out. However this sounds expensive and as the car was running nicely for a week and had no issues, stable idle and nice stable sound I want to be sure that there is nothing else I might have missed.

Thank you so much! Should you need any other details, let me know and I'll add them. Any help is welcome and appreciated!

 

Are the old injectors a greyish color ? If so these are multecs . Contact member Southbay08 to get some new injectors. With ethonal fuel and age the coils break down and short out.

 

http://www.southbayfuelinjectors.com...uel-injectors/

 

Thanks for the quick response!

Yes they are grey actually... So, is there maybe a way to see how they are? the strange thing is I have tried to measure the Ohm values, and the refurbished one was on 12.6 and all other injectors were in the same value. Is this correct or maybe I had a incorrect measurement?

 

By the way! I have re-read my postand found that I forgot to mention that I tried with another set of Injectors as well, however 3 were OEM and 3 were something else not for GM cars... This set came out of another V6 which had pretty bad MPG... But as I was wawiting for the injectors to be cleaned I had to put back something as wither was coming I had to fill the car up with coolant that can take cold and the care produces the same sympthoms... run for a few days, getting worse and worse till stops...

 

I'm not sure the ohm value for the 3.1L v8 are 16 ohms. Southbay would know that answer. The other injector may of had a higher flow value you would need to google there part number on the side of the body.

 

Well they were not even near I am afraid... I'll try to measure them tomorrow again... The 3 other injectors had a part number but google could not give me a clear answer, but those were made for ISUZU or Mercedes Benz trucks... someone probably thought that if those trucks have a 3.X engine it might fit... well the car had the same MPG then my Bros 5.0 GTA Trans am..

I am wondering, if I get a new set and I put them in maybe it will do the same thing as basically 2 seperate sets were installed and the same issue occured. By the way this 50/50 set was working fine on the V6, the engine was strong and had no issues with it at all... but they could not do much in this new block.

Also, I have exchanged the Fuel Bridge (I hope thats the name of that big alu piece which hold the 6 injectors.) Just to be sure that its clean and it came out of a working V6.

I have checked my orders and forgot to say that the O2 has been replaced as well as the MAF sensor.

 

What is the pros for those injectors on the link?
I'm and my brother (who started the topic) not a factory mechanic to we can compare it. Visually looks different then the factory garish stile. But the internal parts are different? I find cutway for the factory style.

Anyone have experience with it? I found the original injectors coil will fail by the age, but as my bro mentioned the card did tha seme with different set of injectors after a few day.

Shortly again what we done or replaced. Fuel tank totally cleaned from mess with acid, and got new fuel pump and stainer (AIRTEX) (, factory fuel lines from tank, (air vent valve cleaned) new fuel filter (acdelco) was installed near by the rear wheel, stock fuel lines up stayed, fuel rail and injectors replaced from a working donor car. And new ignition distributor rotor spark plugs and wires was installed. Plugs are acdelco 1's.

Hope someone can help on us!

ohh A note!!
The new fuel pump is much more noisy then a factory ACdelco types, we think its come from its Chi... design.. And we also replaced the Fuel Pump Pulsator (when the tank cleaning was done), because it looked like a rusty mess. And i had a used spare good looking one.

Hope these infos help too.

 

Replace your fuel filter, if your tank was rusty, you'll need a new filter.

 

As i was write it was done before wit ACdelco brand filter.

 

I believe the multecs for the 3.1L were 12ohms. If you pressurize the fuel system a few key ons and wait a few seconds the fuel pressure should hold atleast 5-10 min before slowly blessing down. It's hard to say if one injectors spay pattern is messed up or if the pinle is not holding either way the multecs are junk.

 

That's fine, but if you had rust in your gas tank before you changed the filter you will still need a new one.

 

The filter has been changed after the tank has been cleared out. We think maybe the fuel line might have some of that rust or that dirty old fuel stuck on the side of the pipe. And maybe during the normal operation some parts of them are coming off and causes me trouble.

Does it make any sense?

 

That is possible. You could try cleaning it out with a really long pipe cleaner.

 

I have ordered a new set of Injectors and when I get them at hand I'll take things apart and get the fuel pipes cleaned out.

I'll let you know how I am with this issue, maybe later on someone else will use this thread for good as well as I do.

In the mean time any further suggestions are welcome.

 

!!! UPDATE !!!

So my car runs and starts fine again... What was the issue? Well.. there was no fuel at all... this time It seems the fuel gauge indicates incorrect values. It tells me that I still have roughly 15l of gas, but when we looked for fuel pressure there was no fuel at all. After bringing some juice to the bird it started right up...

So first thing to solve is that stupid indicator... but now a new issue has occurred. Service Engine lamp - giving me the Code45

The issue is the car was running AWSOMEly smooth for roughly 10 minutes or more, and when it reached the operational temperature, it started to get a little dizzy. All cylinders were running but was not so stable, and then the light popped out.

According to the Haynes book... IT can be:

ECM - I don't think so cause everything else works, I guess if this would be the faulty then the car would not run
TPS - Its an old from the shelf... the car had none when it got to me
Injector - Cleaned original pieces, far away from factory refurbished ones (new set on its way)
Canister Sensor - Just changed it must be good
Air filter - Brand new Airhog
O2 sensor - Brand new ACDelco
MAP Sensor - Old one from a scrap car

So I assume that its either the MAP or the TPS or The injectors... Anyone with the same code having similar issues?

Thanks for all your inputs sofar!!!

 

Hey do not forget to mention we replaced the part called:Air Intake / Charge Temperature Sensor to new after we noticed the code, but did not solved the problem.

 

!!! UPDATE !!!

So I have changed almost everything now

NEW

Map Sensor
O2 Sensor
Air Filter
Sensor at the Canister
TPS

Basically the only thing thats old is the ECM and the injectors. However before I put this set in and had the previous set from another car this code was not present, so it can be that the Injectors are faulty?

To be honest I am not sure how the car gives the 45 code, based on what measures.

Currently, what I think is that the injectors might injcet more fule then needed or be leaking as the car has a strong gas like smell at the back. The other 3.1L V6 I have has no cat on its exhaust and it had the same smell, so I am belieing that the Injectors could cause me trouble now.

Still if anyone has any options or comments on Code 45 please let me know.

Thank you

I forgot to add, the code comes only when it reaches the normal operating temperature, the code comes out even before the fan starts running.

 

Code 45 is O2 sensor reports rich. Basically, once the ECM goes closed loop the O2 sensor signal should be swinging high & low. In the case that the signal stays high for a period of time, sets code 45.

It may be from the injectors that were installed. If they flow too much or are dirty and leaky, there will be too much fuel being injected for the ECM to compensate for.

RBob.

 

Thank you so much, this seems to be the most likely case, I am realy waiting for my new set of injectors... I hope this problem will disappear.

After that I hope I can shut the hood for a long time

 

So I got the issue sorted, with the new Injectors. The car runs like never before! Thanks for all your inputs!