My car will not start and will barely roll over when the injectors are plugged in. when they are not plugged in the car will fire and try to start but falls on its face. i would like to know how is it possible for my injectors to fire when they are not plugged in? Has anyone ever heard of this? ive been workin on this damn thing for 3 weeks now and im about to scrap it.

im having a terrible problem with this and have been chasing it all over the place but just cannot figure out what the problem is. all the injectors are good, ive had 2 different new sets in the car. I just had the motor rebuilt and the car ran fine before that.

87 tpi block
90 prom
map sense

 

It sounds like you might still have an inj. or two that is leaking under power or being told by ecm to dump to much fuel maybe even at the wrong time and once its flooded you disconnected power but still got to start it and sorta clear it out till it runs lean and dies from no power to the inj's.

 

car now idles fine without injectors plugged in

 

The car has to have fuel leaking out of one or more of the injectors or possible fuel pressure regulator leaking in order to allow it to keep running.

 

its not a leak, the injectors are firing on each cylinder like normal as if they were plugged in. ive had 3 sets of injectors in this now 1 old, 2 new

 

Fuel pressure regulator leaking? Try unplugging the vacuum line to it and see if that makes any difference. Also, I see that you have an 87 TPI setup running a 90 PROM - have you removed the cold start injector? It could also be leaking into the intake.

Also, have you checked your fuel pressure? I suppose it's possible that fuel overpressure could force fuel through the injectors, even unplugged.

 

makes no difference unplugging it, already tried. no cold start injector. i have not checked the fuel pressure, if anything it probably doesnt have enough pressure... ive noticed that when i push the ball and check valve down no fuel squirts out like it used too. I do know there is enough fuel pressure because they injectors will eventually flood my car

 

I used an ohm meter and unpluged each injector and checked each one and found one that was bad all read eather 11 or 12 ohms yours should read about the same have you checked yours.

 

This has been a rough week for me too but one thing told me was injector resistance should be around 16 ohms. All mine checked to be around 16.2-16.6 but I'm running a stock 350 so maybe yours are different. Also had my engine try to run with all the injector wires unplugged... it was WAY flooded from a bad ECM injector switch. Hope you find the problem soon!!

 

Injectors can show good values when testing them, that dosent mean they get stucked or something else. The stock injectors dosent have that great of a spray pattern.

Most of all having problems with idle and such on our cars have bad injectors (belive me on this) I had bad injectors to, tried Accel, Ford and it didnt cut it.. didnt idle so well..

Then I found Fuel Injector Connection and Jon there, talked to him and got a set of Bosch III injectors, flowmatched with GREAT spraypattern. I installed them and the car idled and runned so f*cking good Never had better idle and throttle response. (and I tested some innjectors..)

So I would recommend changing the injectors, Jon sells the Bosch III injectors for 169,95 and he leaves 3 years warranty on them.

or just call Jon up and talk to him, he will help you with your injector problems.

Phone : 770-888-1662

Cheers

 

Ok update.....

New injectors, new fuel pressure regulator. The car has the correct amount of fuel pressure i have checked it with a gauge.

It made a few differences. The car does not load up anymore when the injectors are plugged in...and it seems fuel delivery is normal, the plugs arnt covered in gas when i pull them now.... although i havnt cranked it that much. the car still does not fire at all when injectors are plugged in. Now with injectors unplugged the car will start to fire but will not run (i assume its burning the unburnt fuel from when the injectors were plugged in) and soon after loads up and the motor will not turn over. Now by loading up i mean the car will not crank over. I guess it could be compared to hydrolocking... from what people have told me about hydrolocking, ive never had a car hydrolock on me so im not exactly sure im right on in my explanation.

any ideas?

 

Hydro lock is what occurs when the cylinder fills with fluid instead of air. When the piston comes up for the compression stroke it has nowhere to go because fluid does not compress like air does. It is like the piston hitting a brick wall.

This may be your issue. If your injectors are leaking really bad and filling the cylinders with fuel then you may be hydro locking. I would pull the spark plugs out and crank it for a bit. Or you could do a compression test. I would assume that if you are getting a hydro lock situation that you should see the compression rise as the cylinder fills up.

 

Okay so thats what i thought could be happening... now i guess the question is how could this be happening with everything brand new that ive put on my car...