No Start - Have spark, no fuel. Ether will turn it over
Thread Starter
Junior Member
Posts like a V-Tak
Joined: Jul 2007
Posts: 29
Likes: 0
From: Toledo, OH
I installed the new battery and tested the injector voltage. They are all 12 volts. I'm beginning to think that I am chasing two problems.
#1 - no fuel being discharged from the injectors after many start attempts. It will try to start immediately if I give it a shot of ether, but when the ether runs out it takes a while to start it again - the same as usual. I can always get it started but it takes minutes.
#2 - an intermittent failure of one of the coil packs which is giving me the P0361 code.
Is it possible for the fuel system to completely drain down, like a failed check valve in the fuel pump? Could an injector be stuck open and the sytem is draining that way? Even then, I don't think it should take so long to fill the fuel lines, and the fuel pressure is always 50 psig.
I am befuddled...
Thanks for all of the ideas...at least I am having less-and-less to look for.
#1 - no fuel being discharged from the injectors after many start attempts. It will try to start immediately if I give it a shot of ether, but when the ether runs out it takes a while to start it again - the same as usual. I can always get it started but it takes minutes.
#2 - an intermittent failure of one of the coil packs which is giving me the P0361 code.
Is it possible for the fuel system to completely drain down, like a failed check valve in the fuel pump? Could an injector be stuck open and the sytem is draining that way? Even then, I don't think it should take so long to fill the fuel lines, and the fuel pressure is always 50 psig.
I am befuddled...
Thanks for all of the ideas...at least I am having less-and-less to look for.
Guest
Posts: n/a
That is not the proper codes for a 94-95.... There is no P0361...
Its a Manufacture Specific Code and I promise you its a Code 1361... I don't have the time at the moment to look it up or scan the pages for you, But I can and will if you can hold out for a few days..
There is something going on between the ICM and PCM and the Handshake between the 2 is not happening.. For what ever reason the ICM is retaining control or the PCM is not taking control..
When you turn the ignition on, do you get a Fuel Pulse at the first crank... Will the engine run for a few seconds at all? And do you get a Fule Pulse from the PCM while cranking?
At the same token, The Camshaft sensor on these cars is only used as a Cylinder #1 TDC reference for True SFI.... The Crank Sensor is a Dual sensor that has an 18x'* Pulse and a 3x'* pulse... Its possible for one part of the crank sensor to fail leaving you with spark but no fuel pulse..
so we need to find out if you do have that fuel pulse as well
Also what is your location?
__________________
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote
Its a Manufacture Specific Code and I promise you its a Code 1361... I don't have the time at the moment to look it up or scan the pages for you, But I can and will if you can hold out for a few days..
There is something going on between the ICM and PCM and the Handshake between the 2 is not happening.. For what ever reason the ICM is retaining control or the PCM is not taking control..
When you turn the ignition on, do you get a Fuel Pulse at the first crank... Will the engine run for a few seconds at all? And do you get a Fule Pulse from the PCM while cranking?
At the same token, The Camshaft sensor on these cars is only used as a Cylinder #1 TDC reference for True SFI.... The Crank Sensor is a Dual sensor that has an 18x'* Pulse and a 3x'* pulse... Its possible for one part of the crank sensor to fail leaving you with spark but no fuel pulse..
so we need to find out if you do have that fuel pulse as well
Also what is your location?
__________________
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote
Senior Member
Certified GM nut
Joined: Oct 2005
Posts: 1,942
Likes: 1
From: Western New York
The pink wires on the fuel injectors always have 12 volts when the key is on. The PCM fires the injectors by grounding the other wire to complete the circuit. Now that we know you have 12 volts to the pink wires we also know that the PCM is not firing the injectors.
I recently had trouble with our 89 & found the right junkyard can save you a small fortune. Since they don't really know if the parts are good or not they're pretty reasonable about returning them.
I'm thinking you should see if you can pick up an ICM, PCM & the wiring harness that goes between the cam/crank sensors & ICM. Hopefully one of those will get you going. I paid $45 for the computer & he wanted $20 or $25 for the ICM with coils.
The other 2 things that could be the problem would be the the Crank Sensor (as JR already pointed out) & the Vats module which I think is a remote possibility. BTW - how long does the security light stay on when the key is turned to the run position.
I recently had trouble with our 89 & found the right junkyard can save you a small fortune. Since they don't really know if the parts are good or not they're pretty reasonable about returning them.
I'm thinking you should see if you can pick up an ICM, PCM & the wiring harness that goes between the cam/crank sensors & ICM. Hopefully one of those will get you going. I paid $45 for the computer & he wanted $20 or $25 for the ICM with coils.
The other 2 things that could be the problem would be the the Crank Sensor (as JR already pointed out) & the Vats module which I think is a remote possibility. BTW - how long does the security light stay on when the key is turned to the run position.
Senior Member
Certified GM nut
Joined: Oct 2005
Posts: 1,942
Likes: 1
From: Western New York
PS - JR'* right, we should be 100% certain the injectors aren't firing. You can check for fuel injector pulse with a #194 light bulb. Just straighten the wires on the bulb & insert them into an injector harness. Watch for the bulb pulsing while someone cranks over the engine. Look carefully, the bulb never goes on or off all the way - just pulses.
Thread Starter
Junior Member
Posts like a V-Tak
Joined: Jul 2007
Posts: 29
Likes: 0
From: Toledo, OH
The security light only stays on for a couple of seconds. The spare key was the same.
During all of todays testing (probably 20+ starts) the SES light never came on. Since the battery was disconnected for 36 hrs the codes have been erased from the PCM. No new codes have been stored.
Basically I think I'm just seeing a fuel problem. I think one of my misconceptions is that the fuel test port on the regulator represents the rail pressure before a start. I don't think that is the case. I can relieve the pressure with only a few drops escaping from the connection. Tonight when I attached the gauge and bumped the engine I was only seeing 42 psig. A few days ago it was 50 psig. Does temperature have any effect on the fuel pressure regulator? It was in the 70'* last week but mid-90'* today.
Every time I eventually got the car started (sometimes it started right away, others it took several minutes) the scanner indicated normal running conditions with no flags.
Is there a primer on this forum that explains the fuel system? I hear the pump start up and stop when I first turn the key. I can see the pressure gauge rise to 42 psig. Once I start cranking I can hear the fuel pump running (my SO is cranking & I'm listening).
I'm wondering if there is a better place, or if I need some special fittings to measure the true fuel rail pressure.
In regards to the injectors, isn't there a hack to build an LED circuit that you can attach to an injector to see if it'* firing?
I know this may seem like a lot to ask, but these are the thoughts swimming around in my head right now.
Again...thanks!
During all of todays testing (probably 20+ starts) the SES light never came on. Since the battery was disconnected for 36 hrs the codes have been erased from the PCM. No new codes have been stored.
Basically I think I'm just seeing a fuel problem. I think one of my misconceptions is that the fuel test port on the regulator represents the rail pressure before a start. I don't think that is the case. I can relieve the pressure with only a few drops escaping from the connection. Tonight when I attached the gauge and bumped the engine I was only seeing 42 psig. A few days ago it was 50 psig. Does temperature have any effect on the fuel pressure regulator? It was in the 70'* last week but mid-90'* today.
Every time I eventually got the car started (sometimes it started right away, others it took several minutes) the scanner indicated normal running conditions with no flags.
Is there a primer on this forum that explains the fuel system? I hear the pump start up and stop when I first turn the key. I can see the pressure gauge rise to 42 psig. Once I start cranking I can hear the fuel pump running (my SO is cranking & I'm listening).
I'm wondering if there is a better place, or if I need some special fittings to measure the true fuel rail pressure.
In regards to the injectors, isn't there a hack to build an LED circuit that you can attach to an injector to see if it'* firing?
I know this may seem like a lot to ask, but these are the thoughts swimming around in my head right now.
Again...thanks!
PopaDopaDo
True Car Nut
Joined: Jan 2005
Posts: 4,957
Likes: 4
From: NY
The Security light is showing normal and correct operation. It should only stay on if it does not sense the correct chip in the key.
All your dash lights should come on when you first turn the key to run for a sec or two as a bulb check; this is normal and any that don't come on, like ABS or SES needs to be looked at.
The fuel pump should come one for ~2 seconds and then turn off as a prime. It will only turn on again when the PCM detects RPM'*, if I understand it right. Keep the fuel pressure tester on there when it runs, Does pressure stay up or drop off quick? If it drops off quick I would try a new filter; it could be clogged. Frams are infamous for this.
The place to measure the fuel pressure is on the Schreader valve port at the presuure regulator. Another thing to watch is how fast it bleeds off, it should be able to hold that 42psi for at least 10 minutes without the pump running.
All your dash lights should come on when you first turn the key to run for a sec or two as a bulb check; this is normal and any that don't come on, like ABS or SES needs to be looked at.
The fuel pump should come one for ~2 seconds and then turn off as a prime. It will only turn on again when the PCM detects RPM'*, if I understand it right. Keep the fuel pressure tester on there when it runs, Does pressure stay up or drop off quick? If it drops off quick I would try a new filter; it could be clogged. Frams are infamous for this.
The place to measure the fuel pressure is on the Schreader valve port at the presuure regulator. Another thing to watch is how fast it bleeds off, it should be able to hold that 42psi for at least 10 minutes without the pump running.