Tank to pump hose routing

[Yarb]

Exactly what @Zed Head posted in post 49.

[chaseincats]

1 hour ago, Yarb said:

Exactly what @Zed Head posted in post 49.

Right - I just wasn't sure the method of doing it

[Captain Obvious]

Yeah, it's always it's a little risky to go running more fuel lines all over, but I really think you need to do that. Make sure you have a good fire extinguisher with you, just in casel.

In the meantime, I'll think a little about where to go next if you come back and tell us the fuel pressure numbers are just fine under load even when the engine isn't running properly.

[chaseincats]

On 1/24/2025 at 8:12 AM, Captain Obvious said:

Yeah, it's always it's a little risky to go running more fuel lines all over, but I really think you need to do that. Make sure you have a good fire extinguisher with you, just in casel.

In the meantime, I'll think a little about where to go next if you come back and tell us the fuel pressure numbers are just fine under load even when the engine isn't running properly.

Alright, so I just got back from a trip and did some work on the car (trying to avoid a gas shower if I can):

1. Checked for vacuum leaks both smoke testing it and with carb cleaner
2. Used a vacuum gauge and I'm sitting at 16" vacuum which is the same as it has been since last time I checked a few years back when it was running well
3. Ran the car and pulled the injector power connectors 1 at a time and each made the engine run rougher until I plugged it back in - so we know all cylinders are at least working in some capacity

Next steps:

1. Go through the FSM's component checks via the ecu plug
2. Pull the spark plugs and make sure all are firing with the same power
3. Take a gas shower (grab the long fuel line and go for a drive with the pressure gauge)
4. If fuel pressure is consistent, pull the fuel rail, put all 6 in individual cups, crank the engine - surely one (or many) are not working even though they're only a few years old

Anyone have any other checks I should add to the list?

 

EDIT: I pulled the spark plugs and all of them look good except for cylinder #5 which is CONSIDERABLY darker than any of the others.  Could we be looking at our possible culprit?  The car will start only with starter fluid the first time.  After it is started once (regardless of the amount of time it is run), it will start on its own without issue.

EDIT2: I pulled plugs 5 and 6, placed them on the engine, shut the lights off, cranked the car and they both are outputting the same amount of spark.  I pulled the spark wire, put a screwdriver in it, then laid it against an engine bolt and the spark coming out of the wire when it grounds to the metal is however considerably stronger looking than what the plug is outputting.

Edited February 4 by chaseincats

[chaseincats]

9 minutes ago, chaseincats said:

Alright, so I just got back from a trip and did some work on the car (trying to avoid a gas shower if I can):

1. Checked for vacuum leaks both smoke testing it and with carb cleaner
2. Used a vacuum gauge and I'm sitting at 16" vacuum which is the same as it has been since last time I checked a few years back when it was running well
3. Ran the car and pulled the injector power connectors 1 at a time and each made the engine run rougher until I plugged it back in - so we know all cylinders are at least working in some capacity

Next steps:

1. Go through the FSM's component checks via the ecu plug
2. Pull the spark plugs and make sure all are firing with the same power
3. Take a gas shower (grab the long fuel line and go for a drive with the pressure gauge)
4. If fuel pressure is consistent, pull the fuel rail, put all 6 in individual cups, crank the engine - surely one (or many) are not working even though they're only a few years old

EDIT: I pulled the spark plugs and all of them look good except for cylinder #5 which is CONSIDERABLY darker than any of the others.  Could we be looking at our possible culprit?

NOTE: The car will start only with starter fluid the first time.  After it is started once (regardless of the amount of time it is run), it will start on its own without issue.

Anyone have any other checks I should add to the list?

posted this twice somehow - please ignore this

Edited February 4 by chaseincats

[chaseincats]

Tonight's update:

• Pulled all 6 plugs, laid them on the engine, and cranked the car - all have identical spark
• Ran it and listened to the injectors - all click to the same rhythm
• Pulled the PCV valve just for the hell of it - rattles properly
• Confirmed firing order
• Confirmed distributor hadn't moved (timing line I drew hasn't moved)

Some notes about the engine - it is difficult to start if I don't manually trigger the cold start valve.  Once it eventually starts it runs rough but smooths out after a few seconds.  It will run the rich cycle and lean out as it warms up, so the injection seems to be working properly.

@Captain Obvious @Zed Head - I think at this point this weekend really will need to be the 'get some long fuel hoses and take it for a drive' time

Edited February 5 by chaseincats

[Captain Obvious]

10 hours ago, chaseincats said:

 it is difficult to start if I don't manually trigger the cold start valve.  Once it eventually starts it runs rough but smooths out after a few seconds.  It will run the rich cycle and lean out as it warms up, so the injection seems to be working properly.

I'm not sure that is related to the issue you've been working on or not. Next time you try to start the engine from cold, pull the small B/Y wire off the starter first and turn the key to START. You should hear the fuel pump run and prime the system. I'm thinking that your first start of the day difficulty may simply be that your fuel pressure has leaked down since the last time the motor ran.

And yeah... Do the longer fuel line thing and let us know how the fuel pressure looks while driving.

[chaseincats]

41 minutes ago, Captain Obvious said:

I'm not sure that is related to the issue you've been working on or not. Next time you try to start the engine from cold, pull the small B/Y wire off the starter first and turn the key to START. You should hear the fuel pump run and prime the system. I'm thinking that your first start of the day difficulty may simply be that your fuel pressure has leaked down since the last time the motor ran.

And yeah... Do the longer fuel line thing and let us know how the fuel pressure looks while driving.

I've tested that before by pulling the oil pressure sensor plug, turning the key to 'on' and waiting until the fuel pressure gauge gets to 32 before starting and doesn't seem to make a difference for some reason.

 

I'll grab some hose this weekend for sure

[Captain Obvious]

23 hours ago, chaseincats said:

I've tested that before by pulling the oil pressure sensor plug,  doesn't seem to make a difference for some reason.

Gotcha. You probably already mentioned that somewhere. And I hope the under load fuel pressure testing provides some clues to what's going on.

[chaseincats]

10 minutes ago, Captain Obvious said:

Gotcha. You probably already mentioned that somewhere. And I hope the under load fuel pressure testing provides some clues to what's going on.

No worries - I appreciate any ideas to get this fixed. I installed the hoses/gauge/zip tied it to the windshield wiper last night so if I get home early enough, I'll take it out for some answers.

Edited February 6 by chaseincats

[chaseincats]

Update for you:  It is very possible the issue the entire time was bad gas.

I drive it rarely and haven't added any gas to the low tank since I was expecting to have to disassemble the rear again - the last time gas was added was (I believe) mid-October when the hose originally blew.  I took it out today and it was driving terribly as it always does when the red fuel light came on so I added only a couple gallons to it (again, since I was expecting to have to drain the tank) and the car woke up after about 30 seconds.  The AFR numbers returned to where they used to be and its power was back.  The car still smells like gasoline which is possibly due to me apparently using 3/8 hose instead of 5/16.

The final test will be tomorrow morning when I try to start it and we'll see if it's still a chore or if we are really back in business - I will report back.

If the issue really was bad gas all along, I will be incredibly humiliated.

On the road fuel pressure numbers: 30 at idle, 34-36 at WOT, 28 during engine braking

AFR numbers: 13.8-14.2 idle, cruise 14.7, WOT 12.8

 

-chase

[Captain Obvious]

8 hours ago, chaseincats said:

On the road fuel pressure numbers: 30 at idle, 34-36 at WOT, 28 during engine braking

Those numbers look great. 

Here's hoping it was as simple as bad gas!! Hope it doesn't come back!!!