Running Rich?

jrp27540

Active Member
Sep 9, 2016
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I bought an 88 LX 5.0 a few weeks ago. I had a feeling the car was running rich due to the smell from the exhaust. I changed the oil in it last night and the oil smelled of gas. The mods that I have been able to identify at this point are as follows:
  • MAF conversion
  • Cold air intake
  • Bigger upper and lower intake
  • Bigger fuel injectors
  • Bigger fuel pump
  • MSD ignition
  • e303 cam
  • headers
I am used to the 4.6 mustang, but am very very new to the 5.0 fox body. I have been doing some research on this and sounds like it could be a number of things based on the mods done to the car today. I do not see a "check engine" light on, so im not sure if that means the car isnt throwing any codes or not.

At this point, I am looking for any direction that I should start looking at first and work my way down the list. It sounds like I have a large learning curve in front of me with a car that is far from stock... Any nudge in the right direction would be appreciated. I dont want to drive the car until I get this figured out...as im concerned about how much damage has been done to the internals from the previous owner.

Thanks for any information!
 
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I bought an 88 LX 5.0 a few weeks ago. I had a feeling the car was running rich due to the smell from the exhaust. I changed the oil in it last night and the oil smelled of gas. The mods that I have been able to identify at this point are as follows:
  • MAF conversion
  • Cold air intake
  • Bigger upper and lower intake
  • Bigger fuel injectors
  • Bigger fuel pump
  • MSD ignition
  • e303 cam
  • headers
I am used to the 4.6 mustang, but am very very new to the 5.0 fox body. I have been doing some research on this and sounds like it could be a number of things based on the mods done to the car today. I do not see a "check engine" light on, so im not sure if that means the car isnt throwing any codes or not.

At this point, I am looking for any direction that I should start looking at first and work my way down the list. It sounds like I have a large learning curve in front of me with a car that is far from stock... Any nudge in the right direction would be appreciated. I dont want to drive the car until I get this figured out...as im concerned about how much damage has been done to the internals from the previous owner.

Thanks for any information!

can you define what a "bigger intake and injectors" is.? Is the MAF an aftermarket matched to the injectors or a stock Ford unit. Gas in the oil is either because your injectors are too large, an injector is stuck open, a bad FP regulator or incorrect FP setting, or improper tune. Was the car sitting for a long time or was it cranking a lot with a no start situation? You want tp avoid washing out your motor with fuel or you will end up ruining an engine quick.
 
OK, I am finally at the point where I can get the codes. Took a while...

So I bought the "Ford Code Reader" that was mentioned in the thread for extracting the codes. I followed the instructions, but I am having issues getting codes to show up on the reader. I know the reader is successfully connecting to the computer because diagnostics take place when I hit the "Test/Hold" button("I hear solenoids moving and engine revs up, fuel pump kicks on, etc"). However it all stops and no codes are read on the device. It just says 000 and the little arrow is still on showing that its communicating to the car. Any ideas around what I might be doing wrong? I also made sure to push in on the clutch after I hit the "Test/Hold" button.
 
Is the key on position for running your dtc codes test. If your scanner uses a battery, try a fresh one. As far as running rich, yes it could be a malfunction in the fuel regulator. Do a fuel pressure test, check against specs for your car. Also see if any fuel in hose that connects to regulator. If you see fuel out of hose replace reg. as far as too big of injectors, everything I've read says extra fuel if too large should return to tank. You can hear if each injector is functioning with a stethoscope. A shop or friend can maybe do further diagnosis of injectors. to me if you have a stuck injector, that spark plug would be wet with fuel. Pull your plugs/ check. My 2 cents, Moose.


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Yes,the key is in the on position. I just opened the scanner today and put new batteries in it.

The fuel regulator has a pressure gauge on it. See the pic below; its showing almost 50 psi at idle.

Ill pull the black hose and see if there is any fuel in it. Ill also pull the plugs and inspect.

Just to provide some more info around the car. The previous owner replace the original upper and lower intake with an upper and lower off of a Ford Explorer(pics blow). Apparently the intake was bigger on the Explorer.

The car also has a MAS installed. I cant tell if its stock or added. Again the past owner told me it was stock...but from all that I have read only Cal cars had MAF in 88. When I had the dash out replacing the heater core, I looked over the ECU to see if I could see any wire splices that could have led to a MAF conversion. I noticed two (see pic below); appeared to be a red and black wire. Not sure what that is, but someone has added something. The previous owner did install a bigger MAF with the upper/lower intake.

To recap on the other items already listed:
  • MAF conversion (possibly??? Cant tell if its stock or not)
  • EGR elimnator plug
  • Cold air intake
  • Bigger upper and lower intake (From Ford Explorer)
  • Bigger fuel injectors
  • Bigger fuel pump
  • MSD ignition
  • e303 cam
  • headers
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That car needs a tune....The filter needs to go into the the fender well to get away from the fan. Fuel pressure should be set at about 43lbs without the vac line connected.

If you can shoot an email to Willy Lynch at dirtydirtyracing.com he could get you a chip made. He uses Moates Quarter Horse. He's one of the best tuners around and sells QH through their store.

You've got to find out the size of the injectors....color...or part number on injectors.

If you have bigger injectors and a stock MAF without a tuned chip then that's probably why its running rich.
 
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That car needs a tune....The filter needs to go into the the fender well to get away from the fan. Fuel pressure should be set at about 43lbs without the vac line connected.

If you can shoot an email to Willy Lynch at dirtydirtyracing.com he could get you a chip made. He uses Moates Quarter Horse. He's one of the best tuners around and sells QH through their store.

You've got to find out the size of the injectors....color...or part number on injectors.

If you have bigger injectors and a stock MAF without a tuned chip then that's probably why its running rich.

Thanks for the information ! Ill defiantly contact him as I had a feeling a tune was needed with all the changes the previous owner added.

As for your comment around removing the vac line connected to the fuel regulator. Are you saying that I need to remove it all together, or remove it and adjust the fuel pressure then reinstall the vac line? I just want to make sure as I thought the vac line was a must in order for it to control the fuel pressure.

Ill find out the size of the injectors. I know the MAF isnt stock as it was replaced to account for the mods. Im not sure the size of the MAS though; I should figure that out as well.
 
I'd be suspicious of that computer have'n the back open like that. Its a remanufactured I think. Also throttle body and maf looks stock tto me but really can't tell from pics, likely from the explorer that the intake is from, not a bad thing. Need fan shroud and puke tank. At this point I don't think a tune will do any good till you identify some of the claimed mods, but I am not a expert, pervious owner's don't always tell the whole truth and nothin but the truth, does it have a lopy idle?
 
It's always fun trying to get fuel mixtures on pumped motors right. In the old days we'd change jets and needles in carbs. These days with computers and injection, it's not easy. In theory the computer is supposed to richer or lean where necessary, but it don't work that way. Factor in all the hacking that the last guy or two did, and you've got a recipe for trouble on your hands. Correct any weird wiring or splice ins first. Make sure you have right computer. Full ignition tune up, if you haven't already. Try to stay away from made in China parts. Use Ford stuff whenever possible, and get it fuel tuned by an expert. Keep us posted with results. With high performance engines, you might not get it perfect, but you'll get better.


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The first step is to dump the codes with ignition on, engine not running. Do that first and then after it has successfully dumped the codes, start the engine with the code reader connected. Do not turn the ignition off between dumping the codes with the engine off and the engine off.
 
The first step is to dump the codes with ignition on, engine not running. Do that first and then after it has successfully dumped the codes, start the engine with the code reader connected. Do not turn the ignition off between dumping the codes with the engine off and the engine off.

I tried again tonight and I just cant get the ford code reader to give me any codes...the reader just sticks on 000. I hit the start test with key forward and I hear the fuel pump engage and here a click or two under the hood then it stops and no codes are displayed. It just sticks on 000. Same results with the engine on. I start the test on the reader, the engine revs up then goes back to idle...then noting....just 000. The dash doesn't have a light bulb where the check engine light is, so im going to get a test light and see if I can get codes to dump using that method.
 
OK, I got a few hard numbers. The throttle body is 70mm(printed on throttle body). The MAF didnt have a number on it, but it was 2 7/8 inches in diameter which is around 73mm. The fuel injectors have a gray top; i think they are 19lbs injectors based on my google searches. Im going to keep trying to get the codes off of the Eec; its been a royal pain. I cant get codes on the ford code reader, so im going to try the test light method. Thanks everyone for your help; its greatly appreciated!

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