New problem, the day before my KB install

vertigasen · Feb 17, 2009

Well, about a month ago, I posted about replacing my fuel pump with the SVT Focus pump. The install went fine, and after about an hour of priming, it worked. I also posted back about the AFR being all over the place afterwards. I just took it as I needed to re-calibrate the wideband. I only drove it a hand full of times afterwards, but it was running pretty good.

Now for the fun part....

This morning, I decided to drive it to work since I am installing my KB tomorrow (fill up with 94 octane on the way home). I got almost to work, and it started running rough, nothing bad, but rough. When I turned the corner, by my office, the AFR pegged to 20+ it bucked and died. I was at just over a quarter of a tank of gas, and I thought maybe I screwed up the fuel level float. I put 5 gallons of gas in it, and now it reads just over a half a tank (I also used stuff to dry out the gas if there was water in it). My fuel pressure is fine. It will start, but dies pretty quick afterwards. A couple times I started it, and it sputters and stutters and will idle for a minute then die. A couple times it started and bucked a couple times then died.

Here are my thoughts......

1) my fuel injectors took a crap, several at once.....
2) I got some really crappy gas and after it got down so far, it sucked up a bunch (since gas floats on water) and it fouled the crap out of my plugs - but why would it start right up THEN die.
3) My MAF is taking a dump.

Here are some things I could try. I have the 90mm MAF and 39# injectors from KB for my KB install. I have 2 sets of new plugs (764's I had for my next change, and br7ef's for the KB install). I also have a new set of xcop coils.

EDITED: there is no CEL

Anyone have any sugguestions I should try first?

ScortLX · Feb 17, 2009

Hey man! I'm sure someone will be able to help soon. I would, but I'm not too knowledgeable in the FI realm. I know a few guys and tuners in CO that may be able to help out as well. PM'd you.

lazerred02 · Feb 17, 2009

Do you hear the pump come on when you first turn the key on? If so how does it sound?

blkhorse · Feb 17, 2009

from reading your first post,sounds like the pump install did not go right.esp since you said it took an hour to prime,two key cycles at most should do it.

vertigasen · Feb 17, 2009

oh yeah, the pump comes on and sounds fine. When I thought that I might have messed up the fuel level float, I re-primed the system and completly removed the fuel pressure sender (where the shrader valve used to be). When the car was turned on, fuel flowed very well from the rail. I am seeing plenty of fuel pressure, sitting about 40, when I start it, it drops initially to about 30 then right back to 40.

SaleenGT2001 · Feb 17, 2009

unplug the MAF and start the car. it should idle with the MAF unplugged, just dont take it over 3K

vertigasen · Feb 17, 2009

blkhorse said:
from reading your first post,sounds like the pump install did not go right.esp since you said it took an hour to prime,two key cycles at most should do it.

I was on my phone typing earlier, so now that I am home, I had some time to think about it. When I primed it, I also cleaned the MAF and air filter. It started right up after that. I am thinking it could be the MAF. First thing tomorrow, I will clean the MAF and see how that works. I am getting fuel, that doesn't seem to be the problem, but I dont know the symptoms of a screwey MAF. Before the problems with the fuel pump, my AFR was pretty consistant. After I did the pump and cleaned the MAF (with MAF cleaner), the AFR was bouncing everywhere. I just thought I might need to re-calibrate it, but this makes me wonder.

Would a dirty/screwed up MAF cause it to go really lean and not keep it running?

mat82284 · Feb 18, 2009

vertigasen said:
Well, about a month ago, I posted about replacing my fuel pump with the SVT Focus pump. The install went fine, and after about an hour of priming, it worked. I also posted back about the AFR being all over the place afterwards. I just took it as I needed to re-calibrate the wideband. I only drove it a hand full of times afterwards, but it was running pretty good.

Now for the fun part....

This morning, I decided to drive it to work since I am installing my KB tomorrow (fill up with 94 octane on the way home). I got almost to work, and it started running rough, nothing bad, but rough. When I turned the corner, by my office, the AFR pegged to 20+ it bucked and died. I was at just over a quarter of a tank of gas, and I thought maybe I screwed up the fuel level float. I put 5 gallons of gas in it, and now it reads just over a half a tank (I also used stuff to dry out the gas if there was water in it). My fuel pressure is fine. It will start, but dies pretty quick afterwards. A couple times I started it, and it sputters and stutters and will idle for a minute then die. A couple times it started and bucked a couple times then died.

Here are my thoughts......

1) my fuel injectors took a crap, several at once.....
2) I got some really crappy gas and after it got down so far, it sucked up a bunch (since gas floats on water) and it fouled the crap out of my plugs - but why would it start right up THEN die.
3) My MAF is taking a dump.

Here are some things I could try. I have the 90mm MAF and 39# injectors from KB for my KB install. I have 2 sets of new plugs (764's I had for my next change, and br7ef's for the KB install). I also have a new set of xcop coils.

EDITED: there is no CEL

Anyone have any sugguestions I should try first?

Umm dude, you need a custom tune to run that fuel pump. You are flooding the engine with fuel because the computer sends out a pulse that requests the fuel for a certain voltage, well when you replaced the pump its sending the same voltage just double the fuel.

I would install the supercharger and throw on that kenne bell tune. If you want to test it first you can throw on the maf and injectors with the tune and go for a drive. IT wont hurt the car if you leave the supercharger off. The tune is just adjusted to add fuel when boost is present.

hotmustang331 · Feb 18, 2009

I bet you have a fuel leak at the pump. 1 hour to prime is excessive at best...mine had simular issues when my GT pump had a small leak. Car took a while to fire up and just didnt seem right....never stalled but I never got that far before I pulled it out.

How are you checking fuel pressure?

darkside03gt · Feb 18, 2009

Hmmmm! Sounds like a possible fuel leek like hotmustang331 said. It should not have taken that long to prime the fuel system after the install. When I did mine it only took turning the key on and it started right up. I would pull the plugs to see what they look like and drop the tank again and check to see if anything came loose or the fuel sock is gunked up.

I dont think you would need a tune in order to run that pump though since it is a slight upgrade from your stock pump. I had a slight issue with my fuel pressure reading reading too high via datalog but when the pressure was checked at the rail it was found to be in the right range. During this 2 day ordeal I had the car re-tuned and we even tuned it as if the stock pump was in the tank and the car still ran fine so I dont think you really need a dyno tune to run the pump.

vertigasen · Feb 18, 2009

This morning, I went out and unplugged the MAF, it started right up. I also re-calibrated my wideband. I took the MAF out and cleaned it. When I was putting it back on, I noticed the grommet that holds the intake tube to the air filter (MAC) was loose and there was about a 1/4" seperation. I guess it may have sucked up some dust through that gap. Anyway, after cleaning everything, the AFR was pretty much stuck at 14.4. That was back where it was before all of this started up.

Thanks for everyones help! The KB install will start on Friday.....

New problem, the day before my KB install

vertigasen

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