Sidewalk
Probationary Member
- 5
- 0
- Feb 6, 2006
-
Alameda,
California
Quick symptoms:
-Running fine, then died.
-Cranks fine, no start.
-No CEL
-No spark
-No fuel pump
-12v to the pump bypass by the firewall, still no pump
-Ground the fuel pump relay and the pump runs
-Ground the other side of the relay, the CEL comes on
-All fuses inspected and look fine.
-Assistance over the phone with a person using All Data with me using the Chiltons to try and cover as much as possible before replacing parts
A friend of mine picked up a '91 GST (GS?) non turbo 5 speed recently. It was running but wouldn't pass smog, so the previous owner just gave it away and bought a new one (must be nice huh?). After pulling the plugs, it was easy to see why it failed (sure that will be the cure).
However, the main concern is that the car suddenly died while driving. It was a nice night, no rain. The car was running fine, then the engine died. She gave my wife a call and I went out to go look at it (I thought she had a dead battery and it wouldn't start, so I didn't bring any tools, oops). First thing I did was get in and crank it to see what it sonded like, all was normal. Thought about checking the timing belt, then decided to check something simple first, fuel pump (more as a novelty, since I had lost a fuel pump in the bad part of town, and replaced it on the side of the street). I crawled underneath while they turned the key, no whine from the pump. I checked what I could with what little resources I had, ended up with a AAA tow home.
Next day I brought my tools and started troubleshooting. My friends father is a car mechanic by trade (I am a shipboard mechanic, specializing in HVACR, ars by hobby) and he is assisting me over the phone using his All Data software. Tried 12v to the fuel pump bypass on the firewall as per the book, no pump. Tested for 12v at the pump, nothing. Checked the fuel pump relay, and when grounded, the fuel pump would run. Decided to check for spark (changed the plugs while I was at it, since they were in need), no spark. Started leading me towards engine management. I have yet to see an ECM fail, only dirty connections and bad grounds that made it appear like there was a bad ECM. However, I checked everything I could think of; fuses, grounds, dirty connections and the relay itself. Unless I am missing something (I hope), everything points towards the ECM. If it was not powering up, it would not ground the relay for the fuel pump. However from what it looks like, the other part of the relay is for the ECM itself, and it will not click over to provide power to the ECM (it will when grounded).
Where does that relay get its signal to power up the ECM?
I finally broke down and decided to try and find a good ECM from a wrecked car, but didn't make it before closing time today. But I did pull out the old ECM first to see if I could find evidence that it failed, and nothing is out of the ordinary. No pitting, burns, darkening, nothing. All the pins are clean, nothing looks wrong. Leads me to beleive that it is good afterall.
Unfortunately, my friend doesn't have a lot of money to throw at the car, which is half the reason why I have done so much troubleshooting to begin with. The other half is I hate throwing parts at a problem, I rarely fail to find the problem through troubleshooting methods without replacing parts. I like to figure out the problem, then replace parts, not the other way around. But if we can't figure out the problem, I am recommending that she sell the car to a salvage yard, something I don't want to do.
From my search, the problem sounds similar to this:
http://www.dsmtuners.com/forums/showthread.php?t=213387&highlight=Died
I am going to try and test the power resistor, if someone can tell me what that is
Not sure what end caps are refered to here. When I think of a cap when it comes to an ECM, I think of a capacitor. Not much to leak out there (and indeed, no physical evidense of a chemical leak on the ECM either). I will also check out all the engine sensors, even if it does sound a bit odd. What is the CAS?
-Running fine, then died.
-Cranks fine, no start.
-No CEL
-No spark
-No fuel pump
-12v to the pump bypass by the firewall, still no pump
-Ground the fuel pump relay and the pump runs
-Ground the other side of the relay, the CEL comes on
-All fuses inspected and look fine.
-Assistance over the phone with a person using All Data with me using the Chiltons to try and cover as much as possible before replacing parts
A friend of mine picked up a '91 GST (GS?) non turbo 5 speed recently. It was running but wouldn't pass smog, so the previous owner just gave it away and bought a new one (must be nice huh?). After pulling the plugs, it was easy to see why it failed (sure that will be the cure).
However, the main concern is that the car suddenly died while driving. It was a nice night, no rain. The car was running fine, then the engine died. She gave my wife a call and I went out to go look at it (I thought she had a dead battery and it wouldn't start, so I didn't bring any tools, oops). First thing I did was get in and crank it to see what it sonded like, all was normal. Thought about checking the timing belt, then decided to check something simple first, fuel pump (more as a novelty, since I had lost a fuel pump in the bad part of town, and replaced it on the side of the street). I crawled underneath while they turned the key, no whine from the pump. I checked what I could with what little resources I had, ended up with a AAA tow home.
Next day I brought my tools and started troubleshooting. My friends father is a car mechanic by trade (I am a shipboard mechanic, specializing in HVACR, ars by hobby) and he is assisting me over the phone using his All Data software. Tried 12v to the fuel pump bypass on the firewall as per the book, no pump. Tested for 12v at the pump, nothing. Checked the fuel pump relay, and when grounded, the fuel pump would run. Decided to check for spark (changed the plugs while I was at it, since they were in need), no spark. Started leading me towards engine management. I have yet to see an ECM fail, only dirty connections and bad grounds that made it appear like there was a bad ECM. However, I checked everything I could think of; fuses, grounds, dirty connections and the relay itself. Unless I am missing something (I hope), everything points towards the ECM. If it was not powering up, it would not ground the relay for the fuel pump. However from what it looks like, the other part of the relay is for the ECM itself, and it will not click over to provide power to the ECM (it will when grounded).
Where does that relay get its signal to power up the ECM?
I finally broke down and decided to try and find a good ECM from a wrecked car, but didn't make it before closing time today. But I did pull out the old ECM first to see if I could find evidence that it failed, and nothing is out of the ordinary. No pitting, burns, darkening, nothing. All the pins are clean, nothing looks wrong. Leads me to beleive that it is good afterall.
Unfortunately, my friend doesn't have a lot of money to throw at the car, which is half the reason why I have done so much troubleshooting to begin with. The other half is I hate throwing parts at a problem, I rarely fail to find the problem through troubleshooting methods without replacing parts. I like to figure out the problem, then replace parts, not the other way around. But if we can't figure out the problem, I am recommending that she sell the car to a salvage yard, something I don't want to do.
From my search, the problem sounds similar to this:
http://www.dsmtuners.com/forums/showthread.php?t=213387&highlight=Died
I am going to try and test the power resistor, if someone can tell me what that is
Not sure what end caps are refered to here. When I think of a cap when it comes to an ECM, I think of a capacitor. Not much to leak out there (and indeed, no physical evidense of a chemical leak on the ECM either). I will also check out all the engine sensors, even if it does sound a bit odd. What is the CAS?
