no start problem

[84jag]

according to the person i bought the car from,it has sat for 3 years.all windows up and hood and trunk closed.is there by chance a relay on the driver side under the dash that works with the ignition amplifier.there is a retangled black relay that get's hot when the key is on.my efi diagram shows the coil neg going to the ecu# 1.i changed out the ecu,tried to start the car and actually got to keep it running by pumping the gas pedal this time.if i can solve the power to injector problem,i think we will have it running.

 

[Michael J.]

Have you pulled any spark plugs to look at the condition?

Pull the distributor cap to make sure the contacts and rotor are not corroded.

Check the mounting bolts for the power resistor mounted on the forward end of the r/h inner wheel well below the air cleaner. Check for corrosion. You might not be getting a good ground for the injectors. They get the ground through the housing of the power resistor.

If the car still does not want to run without pumping the throttle, I think you need to clean the injectors to get a good spray pattern.

The gasoline that was in the injector bodies while the car sat for so long turned to gum.

If you have to clean the injectors, disconnect and drain the fuel line that supplies the fuel rail, hook up a short rubber line to the rail inlet and fill the rail with fuel injector cleaner. Let it soak for a day to loosten those deposits.

Reconnect the fuel line and start it again.

 

[84jag]

spark plugs and distributor are fine,but i did not clean the resister bolts or area.i'm also throwing on a new coil,thank's

 

[John S Farrington]

Since it fired up when you pumped the gas pedal (which theoretically does nothing) you might have either a leak of intake air to the fuel injection manifold down stream of the air flow meter or possibly a defective air flow meter. Try substituting an air flow meter known to be good and see what happens. Check for vacuum leaks downstream of the air flow meter. Because it was trying to run while you pumped the gas pedal, I think that the fuel injectors are working. If you can get a light that attatches to the injector trigger signal, confirm that they are being pulsed. The light is very useful and will clear the air about whether the injectors are being pulsed.

 

[Michael J.]

The following is from pg 19-10, Book IV Series III Service Manual:

"MAIN RELAY/PUMP RELAY/DIODE UNIT - Description - Three relays,main relay cold start (located between the red diode pack and the pump relay), Pump relay (farthest from red diode pack) and diode unit are mounted on engine rear bulkhead next to the vehicle battery. When the ignition key is turned, the main relay is activated, connecting the battery circuit to the ballast resisters and the injectors. The relay also allows current to flow to the E.C.U. and the pump switch on the air-flow meter. When the engine is cranked for starting, the diode unit is activated and thus energizes the auxillary air valve, the cold start system and the fuel pump."

I just developed an almost identical problem on my 4.2 87. I'm going to start by replacing the red diode unit.

 

[84jag]

Re: no start problem *DELETED*

Post deleted by 84jag

 

[Steve]

Congratulations!! Great news.

 

[84jag]

ok,have another question.still have to stick something in the afm to run the fuel pump.got power to the plug,is the afm bad.or is it because the filter is off and creating a leak.thank's

 

[John S Farrington]

You either have a bad air flow meter or you have a leak in the air hose, manifold or junctions down stream of the air flow meter. Absence of the air filter has nothing to do with it.