1985 GN No Start

[Rads]

I have a 1985 GN with a long history of not running. I drove the car home from Chicago to Madison, WI no problem. After a short time I started having electrical problems and have taken it to several garages. This was my first mistake. The problem is the problems with the car keep changing. At first it was there was no spark, then it was there was no injector pulse. Now I have no fuel presue as the pump won't run. I have put the following in the car since it hasn't started: (all parts are new) ignition module, coils, spark plugs, plug wires, wiring harness, spark controller, cam and crank sensors, starter, alternator, battey cable. These are the parts that were put in beforwe the final fall (all parts have less tha 200 miles on them): ecm, prom chip (stock) fuel pump. After all this I realized that who ever owned this car before put alot of after market parts on. I removed the external fuel pump as it didn't work any more. It also has 36# Bosch blue top injectors and a fuel presure regulator and the turbo has been reworked. I am really in over my head and any help would be great!!

[Keller]

Do you have a scan tool?

Has the wiring to the pump been altered?

Any fueses blown?

Is the crank sensor set on the right slot?

Has the oil pressure switch in the fuel pressure pump power circut been verified as working?

Can you short the pump test connector to 12v and see if it runs then? (Black connector near the #1 cylinder - should be open. NOT the green tach connector.)

Bosch 36# injectors are not compatible with a stock chip. Will cause the car to run very fat, if/when it does run.

[JHensberry]

Are all your grounds solid for the car?
What is the condition of the positive and neg battery cables?

[Rads]

No I don't have a scan tool but, I can tell oy uthat when I try to get the codes from the service engine light I don't get any response.

The wiring for the fuel pump to my knowledge has not been altered but, i will check again.

I found no fuses blown.

The crank sensor is something I have been wondering about. I was told that you use the slot farthest from the sensor. Is this correct?

I will have the check the oil pressure switch. How do I do this? I am new to auto wiring.

I will check the fuel pump.

I will have to upgrade the prom chip. I just recently learned about the fuel injectors. Will the car start with this chip?

I just finished the wiring harness install this morning and I pretty sure the grounds are all O.K.

The battery cables are all new.

Thanks for all the replies.

[Rads]

I tried the fuel pump this morning with the black connector and the pump worked. Then I pulled the oil pressure switch and when I turn on the key and press in on the switch the pump runs. When you metioned the green tach connector (green) is ths supposed to run to something? I know it is for the tach but I don't have one as this car has the digital dash. I am in the prossess of buying a scan tool. Is Turbo Link a good way to go?

Thanks again for all the help!!

[Keller]

Originally Posted by Rads

When you metioned the green tach connector (green) is ths supposed to run to something?

No. It is an output. Leave it alone and unconnected.

I am in the prossess of buying a scan tool. Is Turbo Link a good way to go?

Its a very versatile one.

[Rads]

I am slowly figuring this out (I think). Is there any way of testing a ECM? I seem to have a crank signal to the ECM but, I am getting no spark or injector pulse. I have Turbo Link on the way. Is this going to be albe to tell me if my ECM or Prom chip is bad. Currently I have no codes other that 12. Thanks

[SLOW_85]

http://www.engraver1.com/help/ecm.gif

Could be the crank sensor or ignition module.

[Rads]

O.K. here we go again. I changed the crank sensor and no go. I started checking voltages at the ECM and everything looks o.k. except for the B 10 (Park/Neutral SW Signal) and I am getting 12 + volts. Could this be part of my problem? Does the ECM not let the car start if this voltage is not correct? I can only hope this is the problem. Thanks again Slow 85 for all the help.

[SLOW_85]

Sounds like a bad neutral switch / wire.
Should be located in the shift console.
Prolly has to give a good signal for the car to start.
I'll check my service manual.