Cough, Cough, Sputter, Sputter!!

[G2sound]

I have now completely bonded with my S1... while changing the fuel filter I mixed my blood with it's fuel, we're blood brothers!!

 

Question:The car seems to be choked for fuel when above 3000 rpm. It sputters as if running out of gas, then will catch and run fine for awhile then repeat. The problem seems more prominent when under stress (rapid acceleration, pulling a hill). After putting a glass fuel filter in line, I noticed that there is a large amount of air circulating in the fuel filter (prior to the pump). Probably the culprit... no?

[slngsht]

well, define "large amount". A way to definitely eliminate that as a possibility is to put a fuel pressure gauge where you can see it while driving, and confirm you don't have a pressure drop.

[slomove]

Remind us again: what engine, carbs, fuel injected, other relevant specs?

[S1Steve]

G2, If you look at the build manual that KESS posted today. You will see that the S1 has two fuel filters. The second one at the firewall is a WebCon filter. I don't think you have the WebCon setup, Give more info on the setup you are running, someone else on this site may well have the same thing, but there may be a second filter from the FI setup that you have in that area of the car.

Is the factory fuel pump , in the trunk, going bad ?????

Also, I thought I read in the description of your car on E-Bay that the gauges may not be working correctly, I hate to ask, but is it that simple that it is running low on fuel ??

I like Mazda's idea, then you will be able to see for your self. Let us know how you make out with a fix.

Edited December 10, 2009 by S1Steve

[G2sound]

Just filled the tank, but it is something that I would do!!

 

Fuel pump sounds fine... high volume jobby under the boot. Regulator (looks a bit hoopdy) at the throttle bodies. Fuel pressure is around 38psi at idle, stays close to that when I rev, but haven't checked it while pushing.

 

"Alot" meaning a tornado of bubbles swarming the filter inside the housing. Looks like alot!

 

Setup is a Zetec 2.0. Not certain of the build... cams are obvious, but unsure of actual displacement, compression, flywheel, etc. (the guys at wirewheel.com are doing what they can to track down whatever info they have on the builder/ prev owners). Has Lumenition individual throttle body FI system. ECU is a british make... not certain the name. Has MAP sensor. I will look for the second filter.

 

The car is AWESOME(!!!!!!) other than this annoying problem. Plenty of power, well balanced, too loud, too much fun, etc.

[G2sound]

Where would I find that build manual??

[G2sound]

OK... no fuel filter at the firewall. Replacing the fuel line to the filter and on to the pump. Fingers crossed!

[11Budlite]

Where would I find that build manual??

 

As provided by Gary K in the other thread: http://www.gmsr.info/pre2007/S1_Manual.pdf

 

Lots of good Zetec/T9 info, even if you don't have a S1.

[snookwheel]

I am not very familiar with a Zetec engine fuel injection system, but had a very similar issue with my Stalker (Fuel Injected 3.8). I tried about everything trying to find it. It ended up being a fairly clogged screen inside the fuel regulator. In my situation, the fuel regulator is mounted on the fuel rail and comes apart pretty easy by removing a C-clip.

 

I sprayed off the screen, stuck it back together and the problem was solved. I did also clean up some scuzzy fuel filters. There was some degraded sealant floating around in the fuel tank that had been causing the issue.

 

Best of luck! Scott

[G2sound]

Problem solved! Found a 1/2" slash in the fuel line just where it attaches to the tank. A PO had covered it with some type of adhesive that had degraded with age. WOW, this car is fun!!!!

[slomove]

Wow, that's a clean way to repair a fuel line!

[S1Steve]

I second the "" Wow", glad you found the leak !

[G2sound]

So after replacing the fuel line with the cut, the "sputtering" problem continued, less often, but often enough that it is annoying. It also tends to stall at stop lights occasionally.

 

I pulled the plugs and found them to be heavily fouled with carbon. Replaced with NGK irridiums, replaced the K&N air cleaners that had seen better days and new plug wires... problem persisted. Also alot of backfiring and smoke from the air cleaners on restart with backfires.

 

Figured that it may be running rich (exhaust smelled like it is running rich) so I backed the fuel pressure off while the car was running. got it down to 29 psi (from 38 psi) and the idle speed increased and the idle smoothed out nicely.

 

It now runs much better, the problem persists but occurs much more rarely. Don't want to lean it out any more for fear of burning a valve. I am going to take it to FSR in Montclair next week for a full tune. Keeping fingers crossed. Will post the results. Any additional ideas would be appreciated!