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-   -   Walbro 190 fuel issues! (https://www.miataturbo.net/general-miata-chat-9/walbro-190-fuel-issues-23855/)

mike_671 07-22-2008 04:29 AM

Walbro 190 fuel issues!
 
So this is my set up:
Greddy 6psi intercooled
EMB (no tune)
Vortech 12:1
2.5 inch test pipe back
1.8 injectors

Heres my problem:
So i had some fueling issues last week. I ran a fuel pressure gauge and read 40psi on the stock pump (book say 65 to 85). So then i ordered the walbro 190 LPH and installed it and the car wont even idle and the plugs are black. I cant even give it gas, it just dies. So then i ran the fuel pressure guage on the 190 and it read 25psi. Im confused as fuck and i need help.

olderguy 07-22-2008 06:25 AM

40 is about right for the stock at idle. If you squeeze off the return line it should go to ~80psi.

The 12:1 Vortech disc is much too large for a 190 lph, which will top out around 130 psi.
You are giving it much too much fuel at boost.

At idle there would be no difference if your FPR is in the circuit and is functioning. If you boosted a lot with the current setup you may have screwed up an injector of just filled the cylinders with crap from over fueling while boosting.

mike_671 07-22-2008 12:46 PM


Originally Posted by olderguy (Post 286165)
40 is about right for the stock at idle. If you squeeze off the return line it should go to ~80psi.

The 12:1 Vortech disc is much too large for a 190 lph, which will top out around 130 psi.
You are giving it much too much fuel at boost.

At idle there would be no difference if your FPR is in the circuit and is functioning. If you boosted a lot with the current setup you may have screwed up an injector of just filled the cylinders with crap from over fueling while boosting.

Well my car did idle with the stock pump on but it did it terribly. And when i drove it in boost the car would cut out when im at full spool (4000 rpm) and my plugs were white. I ran this set up for a good 2000 miles and there was no problem till now. Before i changed the Fuel pump i put the 305cc in just to make sure that it wasnt the injectors. And it still acted the same. So i thought it would be pump. Now with the 190 installed its doing worse.

olderguy 07-22-2008 01:02 PM

Your original problem may have been the AFM. Put the 1.8's back in, get a 8:1 disc and run only 8psi until you sort it out.

Make sure you don't have fuel in your FPR vacuum line.

Unless your 305's just came back from cleaning and flow testing, don't trust them.

magnamx-5 07-22-2008 01:15 PM

idk bruce sounds to me like he could have a fubard FPR to esp since he has low idle pressure. I would jumper the FP on and confirm that it works fine and test the pressure, while off and at idle if it does not improve remove and replace the fpr. The afm can make you run poorly and cut the FP out for sure but the pressure of the line is kinda important to. GL man

mike_671 07-23-2008 01:49 AM


Originally Posted by olderguy (Post 286315)
Your original problem may have been the AFM. Put the 1.8's back in, get a 8:1 disc and run only 8psi until you sort it out.

Make sure you don't have fuel in your FPR vacuum line.

Unless your 305's just came back from cleaning and flow testing, don't trust them.

Yes my 1.8 injectors are in. Im still confused at this point. I just need to do more diagnosing. I know there no fuel in the vacuum line. But if im correct shouldnt the miata idle fine with just the walbro 190 lph and the 1.8 injectors with no vortech?

mike_671 07-23-2008 01:52 AM


Originally Posted by magnamx-5 (Post 286323)
idk bruce sounds to me like he could have a fubard FPR to esp since he has low idle pressure. I would jumper the FP on and confirm that it works fine and test the pressure, while off and at idle if it does not improve remove and replace the fpr. The afm can make you run poorly and cut the FP out for sure but the pressure of the line is kinda important to. GL man

Jumper meaning at the diagnose box... right?

mike_671 07-23-2008 04:19 AM

Heres an update:
I took out the pump and re looked at what i did. There was a boo boo that i fixed. The pump wasnt seated right on the O ring. So after i fixed that. The FP read 40psi at idle and 50psi when i revved it to about 4000 RPM.

The next thing im changing is the 02 sensor. When my car is idling (shitty) The narrow band AFR guage reads full rich and when i drive it its reading as far lean as possible. So that will explain Why my plugs are white. So hopefully when i change the 02, It will fix my problem.


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