Still wont run? Help please
07-23-2006 | 02:44 PM
#16
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From: Knoxville, Tn
You may want to take the suspected relay(s) out and use a jumper wire. On my 81 the AFC relay would click like it was working, but it wasn't until I used a jumper wire and learned that the relay was actually bad. Mine would start right away then die due to fuel starvation because my AFC relay wasn't working (it activates the injectors). Just a thought. The jumper wire is easy to make, just do a search.
Hope that helps,
Chris
Hope that helps,
Chris
07-23-2006 | 03:05 PM
#17
Three Wheelin'
Joined: Sep 2002
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From: No Turbo, No SC
Originally Posted by JD928_S4
Ok so there is defiantly plenty of fuel to get atleast one pop out of the engine which is why I am pretty sure it is flooding, could an injector short and cause it to hold all of the injectors to stay open? I didn't think so seeing that if the computer doesn't send a signal there is no power to open the injector. So this is why I think it is a pressure problem. What do you think?
Jacob Duffney
Jacob Duffney
Unless you do as Bill has instructed, you will not really know what state you fuel system is in.
GET A INJECTOR TESTOR! You should be able to find one at your local part store.
http://www.napaonline.com/MasterPage...jection+Tester
http://www.sjdiscounttools.com/atd-5612.html
Originally Posted by Bill Ball
So, your LH is OK.
From the other thread:
https://rennlist.com/forums/928-forum/282496-need-an-87-928-in-albany-for-lh-brain-test.html
You have spark.
You have fuel in the rails.
Car will start on starter fluid.
This points to the injectors not firing as a good possibility. This can be verified with a noid light and injector tester. The noid light establishes whether the injectors are getting an electrical pulse and the injector tester listens for the solenoid action.
I can mail you my testers if you can't get them locally.
Another lister had a no-start condition like this. After verifying the injectors were not firing as I mentioned above, he located a short in one of the injector leads. This will prevent all the injectors from firing. Go ahead and remove the fuel rail covers and pop off the harness leads (they wiggle off each injector). Look for bad boot and look at the wiring inside the boots. That's how he found the short.
You could also look for 12V on the injector leads as Loren mentioned here:
https://rennlist.com/forums/showpost...57&postcount=5
From the other thread:
https://rennlist.com/forums/928-forum/282496-need-an-87-928-in-albany-for-lh-brain-test.html
You have spark.
You have fuel in the rails.
Car will start on starter fluid.
This points to the injectors not firing as a good possibility. This can be verified with a noid light and injector tester. The noid light establishes whether the injectors are getting an electrical pulse and the injector tester listens for the solenoid action.
I can mail you my testers if you can't get them locally.
Another lister had a no-start condition like this. After verifying the injectors were not firing as I mentioned above, he located a short in one of the injector leads. This will prevent all the injectors from firing. Go ahead and remove the fuel rail covers and pop off the harness leads (they wiggle off each injector). Look for bad boot and look at the wiring inside the boots. That's how he found the short.
You could also look for 12V on the injector leads as Loren mentioned here:
https://rennlist.com/forums/showpost...57&postcount=5
07-23-2006 | 04:24 PM
#18
Under the Lift
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If the car fires easily on starter fluid, you are NOT flooded with fuel.
Also, as to the relays, in a no-start condition, I jump the fuel pump, ignition and LH relays (all 30-87). If the car starts, then I remove the jumper and put each relay back in one at a time until it fails to start, identifying the cultprit. Of course, if it doesn't start with the jumpers in place, then you need to look somewhere else. You may have done this already, but if not, you need to.
Also, as to the relays, in a no-start condition, I jump the fuel pump, ignition and LH relays (all 30-87). If the car starts, then I remove the jumper and put each relay back in one at a time until it fails to start, identifying the cultprit. Of course, if it doesn't start with the jumpers in place, then you need to look somewhere else. You may have done this already, but if not, you need to.
07-24-2006 | 07:31 AM
#19
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From: Buffalo, NY or Albany, NY
The only way it starts on starter fluid is if the fuel pump fuse is removed. If I put it in and attempt to start the car with starter fluid it doesn't pop at all again. but remove the cars own fuel system by taking out the fuse it will pop on starting fluid again. Isn't this indicative of flooding?
Thanks
Jacob Duffeny
Thanks
Jacob Duffeny
07-24-2006 | 01:38 PM
#22
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From: Buckeye, AZ
Originally Posted by JD928_S4
The only way it starts on starter fluid is if the fuel pump fuse is removed. If I put it in and attempt to start the car with starter fluid it doesn't pop at all again. but remove the cars own fuel system by taking out the fuse it will pop on starting fluid again. Isn't this indicative of flooding?
Thanks
Jacob Duffeny
Thanks
Jacob Duffeny
07-24-2006 | 01:57 PM
#23
Chronic Tool Dropper
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It sounds like you might have injectors open all the time. The injectors fire when one side is grounded (or very close to it) by the LH controller. One side of the injectore is always hot, while the other side is alternately grounded and left open. When grounded, fuel flows freely.
All that said, you can use an ohm meter to flesh out a spurious ground in the injector harness. Pin 18 on the LH brain on my 1989 car is the connection to the ground/low side of all the injectors. With the battery ground lead lifted, pull the harness connector off the LH brain. Locate pin 18 in the harness, and use your ohm meter to check for any continuity to ground. If the meter reads less than infinite resistance (no continuity at all) between pin 18 in the harness and chassis ground, you need to start looking for a frayed harness section or something similar where you have a stray ground.
Some of this diagnosis is available using the noid tester on the injectors (light is on steady), but the LH harness plug connection is easier to get to and you don't get your hands dirty.
Report back with what you find, please.
All that said, you can use an ohm meter to flesh out a spurious ground in the injector harness. Pin 18 on the LH brain on my 1989 car is the connection to the ground/low side of all the injectors. With the battery ground lead lifted, pull the harness connector off the LH brain. Locate pin 18 in the harness, and use your ohm meter to check for any continuity to ground. If the meter reads less than infinite resistance (no continuity at all) between pin 18 in the harness and chassis ground, you need to start looking for a frayed harness section or something similar where you have a stray ground.
Some of this diagnosis is available using the noid tester on the injectors (light is on steady), but the LH harness plug connection is easier to get to and you don't get your hands dirty.
Report back with what you find, please.
07-26-2006 | 11:32 PM
#25
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From: Buffalo, NY or Albany, NY
So I pulled the vaccum line off the front fuel pressure dampener and fuel squirted out... of the vaccum line so I am guessing the rear pressure dampener is bad and causes the vaccum lines do fill and dump Gas into the engine! well I ran out of time for tonight but I will pull the line off the rear fuel pressure dampener to be positive that is where my problem lies... But time will tell Ill keep you all informed.
Thanks for all your help
Jacob Duffney
Thanks for all your help
Jacob Duffney
07-27-2006 | 03:15 AM
#26
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Jacob--
If yopu have a Miti-Vac or have acess to one, thei is one of the tests that it's good at. For instance, if you find that you have gas just above the front pressure damper in the vacuum line, it's a good bet that this is the damper that is leaking. There's no good way for the fuel to migrate in the vacuum hoses from a rear damper or the regulator forward to the front damper. The Miti-Vac will confirm which damper doesn't hold vacuum, of course. You can also pull the vacuum lines off and spin the engine a little to get the fuel pump to run, then look to see which one the fuel came out of.
If yopu have a Miti-Vac or have acess to one, thei is one of the tests that it's good at. For instance, if you find that you have gas just above the front pressure damper in the vacuum line, it's a good bet that this is the damper that is leaking. There's no good way for the fuel to migrate in the vacuum hoses from a rear damper or the regulator forward to the front damper. The Miti-Vac will confirm which damper doesn't hold vacuum, of course. You can also pull the vacuum lines off and spin the engine a little to get the fuel pump to run, then look to see which one the fuel came out of.
07-27-2006 | 03:41 AM
#27
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Joined: Sep 2002
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From: No Turbo, No SC
Sounds like you have a dampener problem, but I will bet it's not the only problem you have.
Have you pulled any of the plugs to verify your cylinders are in fact flooding?
Have you been able to verify your injectors are working at all or staying open or closed?
Have you pulled any of the plugs to verify your cylinders are in fact flooding?
Have you been able to verify your injectors are working at all or staying open or closed?
