28 replies to this topic

[SaulSpeedwell]

Don't disagree with logging fuel pressure.

Why do so few use a visible (outside the windshield)  fuel pressure gauge with snubber?

 

My opinion:  Because why try to save $100-ish to run a mechanical gauge on the outside versus just running an electronic gauge with 2-3-ish fewer high-pressure joints to worry about atomizing fuel all over the engine bay or windshield?   (I don't love the SCCA fuel port for similar reasons, and I get nervous when people don't run the cap on the port itself!)

[Bench Racer]

Different Strokes For Different folks. Frugal me will trust a mechanical system with joints long over an electrical system. My fuel port and any car I work on has the cap. Cleaning the engine bay now and then is goooood.

[Brandon]

Check your battery tie-down too.

 

I only had cut-out issues in turns at WGI when going over the curbs. The damn battery was vibrated to the right (on left-hand turns) and would short out the positive post on the tie-down bracket.

Taped it up, put a block of wood on the right side, even double-stick tape on the bottom has finally cured it from moving under the bracket.

 

Might be time to get a new bracket I think...

[Ron Alan]

Different Strokes For Different folks. Frugal me will trust a mechanical system with joints long over an electrical system. My fuel port and any car I work on has the cap. Cleaning the engine bay now and then is goooood.

My last build(PTC car)had all quality electric stepper gauges...so simple/clean/ACCURATE! Will never bother with mechanical gauges again!

 

Your absolutely correct Saul...did not have a cap on the schrader valve test port at the FPR and when it started leaking very slowly it took awhile to figure out why i kept smelling fuel! 

[Jack Martin]

I read this thread and decided it was a good place to post my problem.  1992  1.6 NA. 125K miles. Car has been sitting for 12 years

 

I have a bad stumble on left hand corners as I accelerate out of the corner. I didn't see the tach drop to zero.

1.  1/3 tank of gas then added 5 gal. No change.

2.   New fuel pump (before problem started.). Pulled it out, checked sock, fuel return and wiring and all looked good. Tank baffle looked good.

3.   Thinking electrical I hot wired pump and cleared up problem.  (ABAB test). Tested in our parking lot with a max speed of around 22-24 MPH.

Not wanting to run a hot wired pump. I will check the wires on the cam angle sensor.   Is there a roll over safety switch and where is it?

Any other ideas where to look for an electrical problem?

One other possibility.  It may be heat related as it started after about 5-6 laps.

 

Any help is appreciated.

Thanks

[Alberto]

Had the same issue with 2 different cars. On the 1.6 it was in the harness right around the steering column...loosing fuel pump power. 

 

Have you tried this?

[Jack Martin]

I will check that.

Thanks

[Tom Hampton]

I had the same issue a couple years ago. Turned out to be poor contacts in the fuel pump connector. Used a dental tool to squeeze the socket contacts tighter.

[RWP80000]

When the check valve went bad on my '99 fuel pump, it would do similarly "instantaneous" fuel pressure drops with anything less than ....say ... 3 gallons in the tank?  Only in sharp left turns, IIRC.   There may have been other pump problems beyond the check valve, but the line pressure would definitely drop to <15psi pretty much as soon as you keyed off.  And the engine wouldn't fire back up until 10+ crank revolutions and the fuel pressure got back to high 30s psi. 

 

 

 

Saul's comment above aptly describes the symptoms of a recent failure which occured on our original 2011 99 SM build.  Turned out to be due to the deterioration of the short rubber connecting hose between the fuel pump and metal pipe on the tank pump module. It started out as a fairly small drop in fuel pressure with some intermittent signs of fuel starvation but pretty quickly developed into a serious leak internal leak from this approximately 2 inch length of fuel hose.  Lucky for us it was a simple and easy repair to replace this piece of hose.  Given the oxegenated fuels currently in use, I would recommend replacing this hose every year or so as preventative maintenance.

 

Rich Powers