Put the race car on the dyno today for some final runs and double checks before the ARRC. Its a good thing we did, because we are having fuel pressure issues that weren't there before. Big ones. The motor is now "potential to blow up" lean and of course wayyyy down on power.

The only difference between today and the last pulls we did is a change in the rev limiter (bumped up from 6600 to 7400). This could be causing the problem, but we're not sure.
The problem is not at the injectors since we can see the pressure dropping at the gauge on the filter housing, so its definately the filter or upstream from there. The FPR is cranked completely in and we have 60psi at idle. It drops to around 40psi at WOT.

So, here's what we're thinking are the potential issues, in order of likelyhood...
1. The change in the ECU has caused a need for more fuel that the stock pump can't provide.
2. Something is clogged. Either the screen on the pump or the filter.
3. The pump by sheer coincidence chose today to start to give up the ship.
4. Any combination of the above.

We have a much needed test day on Thursday. Practice and qualifying is Friday. So we don't have much time to chase our tales. Any suggestions are highly appreciated.

Car - '91 Civic Standard. ITC Race Car. D15B1 Power.

Scott, who loves racing.
Really. I do.

 

I would check the fuel sock on the fuel pump.. A very common casualty

 

Did you use a air/fuel gauge on your dyno runs? My car's PSI drops on the dyno as well, but the A/F doesn't change..

 

Yes. The A/F is terrible.
Blake has spoken with the ECU chipper and we've determined that the rev limiter bump has caused the problem and we need more fuel. So it looks like Scott gets to drop the fuel tank tomorrow while Blake sources up a fatter pump.
Then we gotta weasel our way back on the dyno.

I really, really do love racing. No ****. I really do.

 

Reminds me of a great quote
"weaseling out of things is the only thing that seperates us from the animals, well besides the weasel." Homer J Simpson

goodlcuk

 

Who did you find to chip a Dual-point ECU? IM me if you want to keep the info off the board.

 

Just a question:
is there some reason you are running 60psi?

Stock on those 88-91 sohc's is only around 29-32 (with the vacume hose on).

 

sounds like you're running out of pump capacity. Clogged or worn out maybe?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Todd00 &raquo;</TD></TR><TR><TD CLASS="quote">Who did you find to chip a Dual-point ECU? IM me if you want to keep the info off the board.</TD></TR></TABLE>

I'm gonna bump this again