flatbedyota

1986 22re and my idle has never been great its always been a little rough....the other day i pulled the vacuum line off of the FPR and my idle smoothed out and it idles great now....could my FPR be bad??

abecedarian

I know, dumb question, but did you plug the vacuum line when you disconnected it?

flatbedyota

i did it either way and both ways it ran the same...better well smoother i havnt driven it down the road with the line off...and the return line on the FPR if i take it off while its running it pours gas out wich i think it is supposed to do

abecedarian

actually sounds like the pressure regulator is working since the engine operation changes when the vacuum line is disconncted. so you may have a defective fuel up vsv, (it's at the other end of that vacuum line, blue in color I believe,) applying vacuum when it shouldn't.

4Crawler

iTrader: (3)

The FPR needs the vacuum line to reduce fuel pressure when the engine is under light load/high vacuum conditions. I just connect mine directly to the intake, eliminating the VSV:

http://www.4crawler.com/4x4/CheapTri...ne_Pix/10.html

If disconnecting the vacuum from the FPR helps it idle smoother that might mean you need more fuel pressure at idle which might mean the fuel injectors are clogged and need the added pressure to inject enough fuel at idle. On my '85, if I unplug the vacuum line to the FPR, it runs rougher at idle and the engine loads up when you rev it until you hit about 2500 RPM.

Might want to test your Throttle Position Sensor to see if it is adjusted properly:
- http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml

flatbedyota

the line runs up to a switch its got another vacuum line coming off of it and an electrical plug on it....i assumed it was a vacuum switching vavle but wasnt for sure...is there ne way to test it besides replacing it??....thanks for the help

4Crawler

iTrader: (3)

The VSV is like a relay for vacuum. Test coil for continuity, check ports for clogging and then you can try blowing through the VSV to see if it works. W/o power I think the flow is input/vacuum to the FPR and with power, the vent line to the FPR:


Or, just bypass the VSV.

flatbedyota

i like the sound of bypassing it...how exactly would i do that...i dont know if it matters but i blocked off my egr

4Crawler

iTrader: (3)

Look at the first picture I posted as well as the web page link. In short, take vacuum line that used to run to the VSV and plug it into the FPR instead.

flatbedyota

ok..but what do i do with the other vacuum line on the vsv and do i just leave the vsv plugged in or do i unplug it???...thanks

4Crawler

iTrader: (3)

Whatever, bypassing the VSV means that it no longer serves any purpose nor does the vacuum line hooked to it nor the wires hooked to it.

I cleared all the stuff off of mine:


Saved the VSV as a spare.

abecedarian

Just though of something... if disconnecting it makes the fuel pressure rise and the engine run smoother, there could be a vacuum leak somewhere else causing the rough idle when the fuel pressure is lower.

flatbedyota

ok i will try that when i get off of work and see what it does....im not saying there is not a vacuum leak, but i just replaced all of the vacuum lines on the truck

4Crawler

iTrader: (3)

Put a vacuum gauge on there and see. They don't cost that much and are handy for testing/troubleshooting.