I made a thread earlier trying to figure out why my car was running lean all of a sudden. I ended up finding the problem which was a vacuum line that hooks to a solenoid that activates the second fuel pump on my double pumper had blown off. I fixed it and went out to log the car. It helped but its still not right. When the hose was blown off my a/f were around 14.2 at WOT. Now with the hose fixed they are at 13.0 which is better but needs to be around 11.8 like it used to be at WOT. I ran a tank of 93 octane through the car and waited till my gas light was on and drove a little more until I filled back up with e85. Could the little bit of 93 octane that was left in my tank be causing it to still run a little lean? Could I have damaged one of the fuel pumps while running it with the solenoid not being activated? Please help. I need some suggestions.

 

Oh and I also installed a new wideband sensor thinking that was the problem from the get go.

 

what is your idc like? Are you sure both pumps are coming on? I had my hobbs switch go once and was thinking it was the pump so I brought two new pumps and later found out it was the hobbs switch.

Good luck

 

Sorry to sound like an idiot but what parameters do i set to log my idc on my AEM? And obviously something different is happening now that my vacuum line is hooked back up to my hobb switch bc my a/f went from 14.2 at wot to 13.0 after hooking it back up.

 

I will send you a pm. I run aem also.

You dont sound like an idiot either, if you don't know you don't know. No worries.

 

Would it be possible that I damaged the primary pump bc while the hobbs switch was disconnected the primary pump was trying to do the work of 2 pumps?

 

Check the vacuum line/hose of the fpr.

 

the fpr on the end of the fuel rail right? The line to it is fine.

 

I would replace both pumps with new ones considering what is at stake. Pay me now or pay me later.

 

check vacuum lines on ur intake mani for loose connections make sure all secure, and no slits in the lines, other thing is check your intake pipe for any holes, also for any missing fittings. any thing pre turbo or post intake mani with vacuum lines, can cause it to run lean. Now did you do the basic like checking the vacuum lines behind throttle body by the egr area. one of those pop off it can cause the car to run lean.

 

yea I did a boost leak test and all the vacuum lines were in good shape after fixing the one to the hobbs switch.

 

When I pull the double pumper out of the tank how will I know which pump is the primary one?

 

Dirty fuel filter? I am having a similar problem with mine too.

 

I think one of my fuel pumps is damaged from the hobbs switch being disconnected and the primary pump was getting over worked trying to do the job of two pumps. Like I said though is how do you know which fuel pump is the primary when you pull the cradle out of the tank?

 

I still thought it was your hobbs switch gone bad. I had that happen to me and I had to replace mine.

I sent you the info on how to view your idc with aem.

good luck.