CSi/L - Dirty/rusty tank and associated issues

tferrer

tferrer

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Updated thread title to reflect discoveries..

Firstly, let me qualify these questions - they are only for factory injected cars. I've had a pretty frustrating fuel delivery issue and after digging and researching others with the same/similar issues I've narrowed it down to a fuel pick-up problem. In short, the car stumbles on harder left turns. After new lines, filters and new injection pump I wanted to pose a couple questions to the collective genius of the forum.

1)- CSi/L fuel pickup- Has anyone had a pickup failure? What was the issue with the pickup? Rust, corrosion or something else?
2) Tank- Has anyone had rust particles or a dirty tank clog the pickup or pickup screen?
3 Pickup repair?- If you did have a pickup failure, were you able to repair it? How did it go?

Fire away with responses!
 
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2) - Yes, but this was due to a brand new fuel tank that must have had overspray inside the tank from factory (I stupidly didn't check). After a while the fuel made the paint get soft and clog the screen. It's worth checking if you're having problems IMO.
 

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But I thought I did, it turned out to be the horseshoe pickups on the distributor were dirty, so on one side not telling the ecu to send fuel via the injectors. I fitted a pressure gauge into the fuel system to see what pressure it ran at, that way narrowed it down to electrical. Mine ran off the cold start injector and three cylinders for a few seconds at a time.
 
Thanks guys. The tank was new in 96 so has been in use for years. The cars runs fine until thrown into a hard left turn then the stumble. Straighten the wheel and all is fine. Eliminated electrical as the issue.
 
Time to pull the pick up & replace the screen. I used a siphon to clean up the sediment in the tank, has been fine for 11 years now.
 
Just a hand siphon pump into a 5 gallon bucket. Move the long end around like a vacuum for all the fine sediment.
 
tferrer said:
In short, the car stumbles on harder left turns. After new lines, filters and new injection pump I wanted to pose a couple questions
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A clogged pickup filter could cause fuel starvation. However, your symptoms may indicate some other cause of your fuel starvation issue.

You did not mention whether the problem occurs when the fuel tank is full or near empty. If the pickup is severely clogged one might expect the problem to occur regardless of turning. As a simple “field” repair, blowing through the fuel lines at the tank to dislodge any debris from a suspected clog is easy enough. If there is minimal pressure encountered when back-washing or reverse-purging the suspected clog, it is likely that the suspected clog - at the tank pickup - is not the problem. Since you mentioned replacing various parts, what about the fuel expansion tank adjacent to the pump? Do you still employ the tank and, if so, is it free flowing?

You mention replacing the fuel pump, but that would not necessarily eliminate the possibility of other electrical-related problems. The fact that your problem seems to occur only when making a hard turn leads one to question the wiring and connections to/at the fuel pump. (There are also relays at play, especially the fuel pump relay near the brake booster - that might, if original, be affected by electrical gremlins). In any event, if an electrical connection to the fuel pump is loose, corroded or dirty, when the vehicle is turned, could the wiring be flexed sufficiently to cause a momentary failed connection - thus causing a temporary loss of fuel pressure?

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I like using glass fuel filters as it really shows the gunk/rust that comes out of the tank, which mine does A LOT! Gotta clean out that tank soon!
 
Well it's been a job that I've been putting off because I can't stand working with gas but after getting the replacement screen and rubber pickup gasket, I couldn't put it off any longer and delved into opening the tank to visually inspect the tank bottom from the fuel pickup opening. I was expecting to see some debris but nowhere near the level of what I ran into. The pocket the fuel pickup sits in was almost full of debris. It looked like rust and broken down varnish type of material. I was using a cheap Harbour Freight hand pump that worked for the initial couple of strokes but there was so much debris that it fouled the pump and started reversing the flow and stirring up everything at the bottom of the tank. I've ordered an electric transfer pump which probably won't make it through vacuuming up everything from the tank but hopefully it will get me 90% of the way there. To be honest I'm surprised the car was running as good as it was with the amount of trash in that area of the pickup... I'll update the thread after I get the pump and see how things go.
 
Update on the fuel tank cleanup project. After using a regular siphon hose with limited success, I bought a 12 volt transfer pump and ran some inline fuel filters on the intake side. There was so much debris coming off the bottom of the tank that the first filter was full and clogged within a couple of minutes. In reviewing some of the debris it was apparent a combination of rust and a bit of old gas sludge was the issue. There was 15 gallons of gas in the tank when I started the project, so three 5 gallon gas cans were filled. After making sure I moved the suction line around inside of the tank to the areas where I could see debris, I probably got 95% of it picked up while filling another Wix inline filter up with debris. In retrospect, I probably could have taken the tank out and cleaned it up without to much more effort, but I really detest messing with gas and fuel tanks so this was, on the surface, an easier route. It's all back together now and we'll see how it does on the next drive. Fingers crossed!
 
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Another update. Since the tank was mostly clean now, I wanted to check further up the food chain. I had to assume that some of the tanks junk was getting through the pickup screen and through the pump and to the filter under the battery bracket. Don had replaced all the soft lines and the filter when I'd gotten the car, probably 500 miles earlier, so the filter was relatively new but I wanted to see what was being captured, hence getting through the pump from the tank. I pulled the filter and upended it into a jar... Check your tank visually boys and girls. You never know what lurks below...

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Don’t forget that funny little conical metal screen that’s fitted to the pump, on the connection going into it. That should stop anything going into the pump, and could be clogged.
 
damienh said:
Don’t forget that funny little conical metal screen that’s fitted to the pump, on the connection going into it. That should stop anything going into the pump, and could be clogged.
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Don swapped in a new pump as the original was getting loud so its on the new pump but it's on the list to check and I'm considering an inline 100 micron pre-filter that I can monitor until everything is running clean again. Just to be on the safe side.
 
tferrer said:
Don swapped in a new pump as the original was getting loud so its on the new pump but it's on the list to check and I'm considering an inline 100 micron pre-filter that I can monitor until everything is running clean again. Just to be on the safe side.
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E28 fuel pump?
 
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