Back on 4 cylinders,but...

[ga.spyder]

I installed the new injector and injector plug this morning.Car is running on 4 cylinders again!!! But...always a but.It will rev nicely and idle in the garage.The new injector is firing(I can hear it with the stethescope).I can pull the injector plug or the spark plug wire and the difference is noticeable.I have #4 back.However,when I drive it the car is running like crap.I am at a loss on what is going on.I am going to double check everything I have done to see if I left something off,etc....I was pumped when I fired it up,but now When it is sitting in the garage it revs beautifully,but under load it is stumbling and stuttering.Any clue what to try next? Stan sent me an email about the coolant sensor but I dont know exactly how to test it.Brad also mentioned the fuel pressure regulator. Any ideas??

[ga.spyder]

Update, I started the car after walking away for a bit.It starts runs,and revs correctly.Took it on the road and in 1st and 2nd it revved fine.I cruised in 2nd to the good pavement where I have a long straight area.As soon as I get into 3rd gear at about 4K,the car starts running on 3 cylinders or at least running like crap.Now,it wont rev thru 1st and second.I got it home,shut it off and now it revs thru 1st gear again.WTF??????? I know the gear has nothing to do with it,but as soon as it is under heavy load it misbehaves.I am begining to think this must have something to do with the ECM?The car is basically undriveable.It cant be a valve spring or similar or my compression would be down,and it wouldnt rev freely when cold or sitting in neutral in the garage.The fuel system seems to be fine,as the injector is firing.I have healthy spark.I am at a loss.If I had someone that knew these cars to take it to,I would trailer it there.I dont.Any ideas? I could leave it on the side of the road with the keys in it,but they couldnt drive it away!!

[RRoller123]

I think bad distributor timing can cause this sort of behavior? Worth checking.

[ORFORD2004]

I have a spare ECU if you need it and Washuko got my AFM but he said he don't use it anymore.

John

[majicwrench]

STOP!! Why would you change the ECU?? Guessing is a good waste of good parts and money and time.
First thing I would do..........."T" a fuel pressure gauge in, hang it on your wiper arm and go for a drive.
Huge diff tween sitting still and reving and being under load. Takes more voltage to fire plugs under load and takes more fuel under load.

One thing at a time. Check fuel pressure, then move elsewhere.
Keith

[Divers]

When you replaced the injector plug how did you splice it? Butt splice, solder, or twist and electric tape? Seems the only 2 things you did was injector and plug.

[ga.spyder]

I used a butt splice and then heat shrink to install the new conn.I am absolutely going to check fuel pressure before changing anything else.After talking to several people,I wasnt confident that it was the injector but I figured at worst I would have a spare.I am really frustrated at this point.Majicwrench and Brad have both mentioned fuel pressure,so I will head there next.Very strange that it starts acting up under heavy fuel/electric demand.I almost guarantee I can walk out and start it and it will start,idle,and rev correctly on all 4 cylinders,sitting in the garage.I did check timing and it is fine.I am pretty bummed right now. I attended FUN(Fiats Up North) this weekend,and drove around in a Ford Focus
John, I may take you up on borrowing your spare ECU,if after further testing it looks to be pointing that way.Someone else offered a loaner double relay.I am not going to spend any more money on the car until I know for sure what is wrong.

[majicwrench]

It is not "very strange" that it acts up under load, that is when things normally show up. Take very little fuel to rev sitting still. Takes very little voltage to fire a pug without a lot of cylinder pressure. I would absolutely NOT install an ECU. Tis not good to be pluggin/unpluggin, it may not be quite the right one, all sorts of things could go wrong.......the more things you change/mess with the more loose ends and potential issues you are CREATING and pretty soon you have a rats nest of biblical proportions to sort out with no good place to start.
I need to calm down. Coffee will help. Breathe deep...........
Keith

[So Cal Mark]

sounds like either low fuel pressure or an issue with the intake boot/afm

[mgbgtn]

If the fuel filter has not been changed it can cause a similer problem. It will clog up when running but will allow enough crud to fall off the filter element to allow it to run for a short while then start to plug up again as it is used.

[ga.spyder]

I did grab a new fuel filter today,I was thinking the same thing.It is fairly new but I have bought gas all over the place this summer.You never know.
Mark,I have 2 working AFMs.I have switched them out,and it made no difference.I took off the intake boot this morning and did a thorough visual inspection.No cracks or tears..it is a pretty new one.
Keith...I know!! I have walked away from the car to calm down and think a few times!!I dont plan on replacing anything other than the fuel filter,until I know what is the problem.I dont want the snowball effect.I borrowed a noid light tonite,and will see about borrowing a fuel pressure guage to check that.The pressure is looking more likely.I do have access to a loaner ECU and double relay,but dont plan on trying that...yet!!!

[majicwrench]

"The pressure is looking more likely" No, it is not, untill you TEST IT and find something lacking. Don't get in the habit of assuming anything.
Fuel filter not plugged, but tis your money, time and car.
keith

[ga.spyder]

Checked this morning using the noid light.I have the same results on all 4 connectors.When I rev the motor they all get bright,no visible difference on any of them.Strike that from the list.Gonna see if I can borrow a fuel press. guage and test that.Getting pretty discouraged.I cant help but think its something simple.On the bright side,I am becoming a expert on pulling injectors

[dmwhiteoak]

Hang in there. The answer is just round the corner.

[Gunsmith]

Mine is at the shop with the same issue right now........I blame you.