Damp, wet weather = engine misfiring. Help please.

[David Inc.]

Then what do you mean when you say that "it floods"?

[JCFL]

If I crank engine for at least 6 / 7 seconds, it smells of fuel when I stop the cranking.

[911obgyn]

I think it comes down to injectors, i have cleaned mine with a can of barrymans a 10cc syringe and a momentary switch set up.
I would have sent them out but needed to putter.
Definitely improved spray pattern.

[JCFL]

Originally Posted by 911 Rod

I don't remember seeing this. So it is getting fuel, just not regulated?

When we crank the engine for about 6 / 7 seconds, we can then smell fuel when we stop. We always thought that meant the engine was getting fuel.

But the carb cleaner test now seems to rather demonstrate that the engine is NOT getting the fuel it needs.

[wazzz]

Have you tried to pull a plug after cranking 6 / 7 seconds when you can smell fuel? If plugs are wet may be the engine gets flooded? Too much fuel and it won't start. That would lead back to an unregulated injector pulse or something.

[Tea Tray]

A spark plug fits the coil wire perfectly, just make sure you have a good ground. Inductive timing lights also are great for checking spark - I’ve taped the trigger “on” so I could do hands free monitoring. I soldered wires with alligator clips to an 1157 (or other fairly bright) bulb and use it to verify power at the coil.
Check the fun to get at injector harness connector back by the firewall. My ‘87 connector was really dirty. Also check the big braided ground wire down by the trans. There are ground point on the engine and behind the fuel filter IIRC.
On the subject of grounds, look at the electrical section of your Bentley, all the ground points are called out.
Check for gross vacuum leaks. My brake booster failed internally and the engine was sucking brake fluid (and flakes of paint!); you can see I have the vac line plugged off.

[Tea Tray]

[JCFL]

Originally Posted by wazzz

Have you tried to pull a plug after cranking 6 / 7 seconds when you can smell fuel? If plugs are wet may be the engine gets flooded? Too much fuel and it won't start. That would lead back to an unregulated injector pulse or something.

Yes you are right. I have verified plug and it smells of fuel, and fuel residue is present.

Looking to examine that injector pulse this week.

[JCFL]

Originally Posted by Tea Tray

Verified those items. Will re-examine.

[JCFL]

Originally Posted by Tea Tray

Hello TeaTray,

What is the item about 3 inches away from the injector harness connector that is showing in your photo ? The connector is circled, and so is this item . . . ?

Thank you.

[JCFL]

Well, after verifying all the items that posters suggested, the problem with my car was that the rust accumulated in the fuel tank completely clogged 5 of 6 injectors.

Look at the photo - that is the color of the stuff that came out of the injectors !

I guess repairing the tank is going to move up the list of items to repair on my car.

Thank you all for your comments and suggestions.

[RobFrost]

The wet weather claim threw everyone if that's the cause. I wonder if water is getting in to the tank somehow.

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[SkunkWorks]

Originally Posted by SkunkWorks

I'd focus back on the basics if it were me at this point: air, fuel, spark. What's missing? Pull each spark plug out and test for spark, pull each injector out and test if and how it's spraying when cranking, etc.

Glad to hear you finally found the issue! On the bright side, after all the diagnosis, you now know everything else is up to snuff.

There could have very well been another issue specifically related to the wet weather that has since been resolved through the new parts and troubleshooting. Hopefully these injectors/fuel tank are the final problem.

[snbush67]

It’s great that you know now what your dealing with. Fixing it ain’t easy. The tank likely needs to be replaced. The fuel pump probably isn’t doing well.

[JCFL]

RobFrost - You are absolutely right that the wet weather claim "clouded" the issue.

SkunkWorks - Indeed, there are some positive things to gather from this journey. Among others, I have been kidding my family that I had registered for an intensive mechanic's course for the summer.

snbush67 - I am wondering about the tank and the pump. If I can clean the tank well enough, I was hoping to wait for the spring to purchase a new one. I am kind of over budget for 2023. But there will be a new fuel filter, and then a second new one not long after the first one.

As to the pump, I was wondering if the impeller is in metal, would the residue in the tank have had an effect on it ?

[JCFL]

Hello,

Since my injectors were clogged up by rust residue, and another brush with poor running at mile 60 of outing, I figured I would clean up the tank. And the fuel lines.

I have a photo below of the strainer after cleaning it - I would not have dare post a photo of the strainer in its the original state. Terrible. I feel bad for not having done this last year, when a funny smell at exhaust, on a low tank, should have alerted me.



Here is a photo of the frunk, with the tank out. I got into it a few days ago and I hope to have no surprises ahead.

I ordered a bunch of stuff from our host today, including fuel filterS with an s, and assorted items related.

[911 Rod]

The tank seal is pretty pricy.

[PeteKz]

That crud from the injectors should not have gotten through the fuel filter. If you haven't already replaced that, move it to the top of your list.

[john walker's workshop]

Originally Posted by 911 Rod

The tank seal is pretty pricy.

Home Depot peel and stick roll of foam door seal. Cheap as dirt.

[JCFL]

Carrera is back on the road.
Did a 350 miles return trip on the weekend.

It went pretty well, although there is still some rust residue passing through the injectors, as we can feel the power shut off when being too agressive on the gas pedal. This is actually good for my drivers' licence ! Ha ha !

Every once in a while, the car will let a small backfire out (very small actually) and then stall when pressing the clutch. Very weird.

I will have to purchase a new tank.
I am not looking forward to seing the shipping cost to the East Coast.