Leaning out now...never did B4!

[waveoff]

My car started acting up today. Normally I'm 2-3 LED's into the green but today it got into the yellow on my autometer a/f gauge! I've never seen this before. I could tell that it was leaning out pretty good because the car was pulling better in 5th than it normally does. However, there was no audible detonation. I've had my JR fuel pump on for about 6 months now. I checked the fuel pressure on my B&M gauge and it looked fine with the vacuum line off and on. The pump sounds normal when I turn the key ON. What could be causing this? The a/f gauge readings are normal for about the first 10 miles and then things start leaning out.

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Fred G.
'97 Civic EX supercharged http://www.geocities.com/motorcity/track/4059
Beech 1900D driver...2,558 shp, 10,000+ ft./lbs. tq., top speed 331 mph

[rjaffey]

Sounds like your fuel pump is dying. You need to watch the pressure while boosting.

[Marc]

Generally I'd say check the pump but you said it's only about 6 months old. Try changing your fuel filter.

Marc

[waveoff]

I wish I could watch the fuel pressure while boosting...unfortunately I have the B&M mounted on top of the filter. My car was fine yesterday with a normal a/f reading and now all of a sudden it decides to play games. I did notice something unusual though. Normally the JR FPR makes that squeaking noise when I turn the key ON and the pump turns on...today, it didn't make that noise. Maybe the FPR took a crap. If so, that'll be a good excuse for me to get the cartech FMU. What should I look for on the JR FPR to see if it has failed?

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Fred G.
'97 Civic EX supercharged http://www.geocities.com/motorcity/track/4059
Beech 1900D driver...2,558 shp, 10,000+ ft./lbs. tq., top speed 331 mph

[Bigkat]

If not the pump(I think it is), then check out your injectors. Sounds like injetcors could taxed under boost. Try running some fuel injector cleaner. My Bosch pump SUCKED ASS, the one from JR. I replaced it with Lude pump and now NO LEAN PROBLEMS. I would try running OEM pump again to see if the problem is the JR unit. Good luck

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'95 Civic EX w/ JRSC(6psi)& Nos 25 shot,JG TB, Stillen 4-1 header, HKS 2 1/4 exh., '93 Lude VTEC fuel pump,MSD 6 BTM w/ Blaster SS Coil,APEXi SAFC, Autometer Boost/ Air-Fuel gauges, Centerforce D/F clutch, Act lighten flywheel, Eibach Pro's,Tokico Illuminas,Tenzo Front/ Rear Strut tower braces Best et: 13.98@101mph w/NOS

IN PROCESS:1992 5g VX Hatch w/ 93 Prelude 2.2L Vtec(donor)

[This message has been edited by Bigkat (edited May 21, 2000).]

[This message has been edited by Bigkat (edited May 21, 2000).]

[waveoff]

Thanks for the great ideas guys...I have tomorrow off so I'll give rjaffey's idea a try. If I have time I'll try the stock pump. Things were working normally today so maybe it was just some freak thing. I was snooping around under the hood looking at all of the fuel lines and didn't notice anything out of the ordinary. However, on the JR FPR the threads on the center nipple (fuel return) were moist. Oh well, I'll see what happens the next few times I drive. Thanks again!

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Fred G.
'97 Civic EX supercharged http://www.geocities.com/motorcity/track/4059
Beech 1900D driver...2,558 shp, 10,000+ ft./lbs. tq., top speed 331 mph

[rjaffey]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>The a/f gauge readings are normal for about the first 10 miles and then things start leaning out.<HR></BLOCKQUOTE>

I seriously doubt the FMU went bad. It really sounds more like a component heating up and failing to perform properly.

One way to test the pump is to let the car sit and cool off for quite a while to where you'd think the A/F will appear normal (or what was normal until you noticed the leaning out recently). Then start the car and crank the FMU baseline adjustment up to see how high you can get the fuel pressure. Then set it back to normal and run the car for 10 minutes or so until you're seeing the leaning out condition. Then pull over and crank in the FMU baseline adjustment back up and see how high you can get the pressure. This won't give you an absolute answer; yes it's the pump or no it's not, however if the peak pressure is significantly lower than before, I'd say the pump is a pretty good place to start.