Another no start

[motorracer]

Help I am going crazy. Read all the stickys my hunch is it might be the alarm module. Any idea where it is 86 930.

[T77911S]

Check for spark
Connect a plug to a wire and try to start it or use a timing light

Check for fuel
Remove the connector on the top rear of the AFM and turn key on to check for pumps running.

[motorracer]

It will run if i jump the red relays.I have good relays that i have changed I no that are good tryed them in another car.

[s5uewf]

I cannot remember between red and black relays - can you tell which position these relays are in (what number on the schematics)?

This schematic may help - it clarifies most of the circuits. Seems weird you can bypass the relay and the engine runs OK, but relays test as good. This seems to me to suggest the relays are suspect. They seem to be the only variable, or maybe the circuit that activates the relay (which I guess you are bypassing manually)

http://forums.pelicanparts.com/uploads24/IMG_2141+copy1443826779.jpg

[motorracer]

Thanks for the reply. Unfortunately I can't work on the car until later in the week. It does seam that by jumping the relays i bypass all the rest of the system.

[T77911S]

remove the connector on the top rear of the AFM
check to see if the pumps run.

ground the wire on the over boost switch.
note: test for running pumps after each suggestion

remove air sensor rly and jump 30 to 87a

if they still don't run you could have a bad speed rly.
most likely a bad solder joint.

[911 Jay]

If the car runs by jumping the fuel pump relays you've done half initial diagnostic work. Simple tests from here to see which way you need to proceed in the circuit.

Terminal 30 is constant power (ruled out as car runs when jumped)
Terminal 87 is power supply to pump (ruled out bad pumps and wiring to pumps as runs when jumped)
Terminal 86 should have power with key in run position. Comes from a fuse that is powered by the ignition switch. Unlikely to be bad but simple to test
Terminal 85 is fed ground from the boost switch on the intercooler. Hook test light to positive terminal of battery and then touch the intercooler with the probe. Should light. Been burned by a poorly grounding intercooler. If cooler is grounded move to the wire on the boost switch. Ground it. Car should start but you won't have any over boost protection. If the car starts, make sure the threads of the boost switch are not coated in Teflon tape or pipe dope. Both will cause no starts or in the very least an intermittent failure.

[motorracer]

Thanks will try that.

[motorracer]

Tried it i have a good ground on intercooler and a ground on 85 no change if i ground the switch. I have a friend with and 86 930 like mine so i am going to bring all my relays and try them on his car to confirm they are good. Thanks for the help.

[T77911S]

how are you checking grounds and power.

use a test light
NOT a MM.

check at the YEL RLY in engine bay.
remove rly and gnd test light. check pin 30 for power with key on.
connect test light to 12v, check pin 87a for gnd.

[911 Jay]

Test for spark. The chances of both fuel pump relays failing at the same time is very slim. These cars will run off one pump, just not well

[timc]

Originally Posted by T77911S

Check for spark
Connect a plug to a wire and try to start it or use a timing light

Check for fuel
Remove the connector on the top rear of the AFM and turn key on to check for pumps running.

Second Post....^^^^^

[motorracer]

Update took all my relays and tried them on a friend's car.all my reds worked the yellow did not so i ordered a new on hoping that was it .no go still the same . I did checked with the light method always lite up so i am still not getting the pumps to run.

[T77911S]

Originally Posted by T77911S

how are you checking grounds and power.

use a test light
NOT a MM.

check at the YEL RLY in engine bay.
remove rly and gnd test light. check pin 30 for power with key on.
connect test light to 12v, check pin 87a for gnd.

I don't know where you are at in testing.

[ayebaal]

I had the same problem a couple years ago, turned out to be the acoumlator. Seamed to become harder and harder to start till it didn't start at all. (79 930)

[motorracer]

The problem is that when i jump the red relays it starts. So somewhere in the system i have a problem. I don't know where it starts from when you turn the key. Is it the red relay to the flow switch to the over boost ect.

[356911930]

Try cleaning your relay prongs with sand paper and spreading prongs with a razerblade to insure you have good contact.


Rahl

[motorracer]

That was the first thing I did and cleaned the fuses to

[motorracer]

On my flow switch i have two brown wires do i ground both.

[motorracer]

I have it running. I am jumping pin 30 to ground on the yellow relay. Now it runs like normal test ride tomorrow if the weather is good.