engine guy in costa mesa area?

Igino

Well-Known Member
I'm looking for someone to help me tune my stock 4L v6 ranger engine. Should be pretty straight forward, but i dunno crap about crap. I've been trying to reach juan in san diego to have a chat with him, but I would love to know of someone closer. I'd be interested in hearing about anyone - but since we are on a budget I would be particularly interested in getting hooked up with some guy that can come over to shop and for some cash tinker around and show us what the heck is going on. I've got a trailer too - so i can bring the truck anywhere it needs to go. Thanks! For the hell of it - here are the symptoms below - if any of you wizards out there can give me a some advice.

- race truck so everything has been ripped out and re-wired (forget about a check engine light)
- Truck runs rough when idling, and sometimes dies.
- Can't get any power out of it. Dies going up hills.
- Backfires occasionally
- I realized that the Heated Exhaust Oxygen Sensors (HEOS) weren't wired up, so i did that and the truck ran WAY worse (what the heck???). It would die everytime i let off the gas after a strong pull.
- I don't think there is a vacuum leak - all the egr stuff has been disconnected.
- I get the feeling its running rich, but i have no way of knowing
- Some old guys have told me it sounds like a timing issue. Once again - no way of know how to check/fix that.

Thanks again guys.
 

Wahl_7s

Well-Known Member
What kinda fuel pump , fuel pressure, MAF sensor, is everything connected. Is it stock? Get a scan tool plug it in (if you still have OBDII port) that will tell you a lot. It doesn't sound like to much gas it sounds like not enough! And it doesn't sound like timing. Check firing order its easy to mess up! #1 cyl is passenger side front, look at the top of the coil pack follow the #'s 1,2,3,4,6,5. On the engine Starting w/#1, it goes 1,2,3 on the other side front to back 4,5,6. I hope this helps keep trying to call Juan he's a genius w/ 4.0's. I forgot to ask, I assume it's a SOHC:)
 

Igino

Well-Known Member
thats for the pointers man - Actually its a single cam with pushrods and rockers so i'm pretty sure that makes it an OHV. At any rate its a '94 4L v6.

fuel pressure - we have an aftermarket fuel pump (not sure what type right now - at work). We're getting 40psi when the fuel pump is on (engine off). About 33 when the engine is idling - up a bit during revs, maybe 35 psi.

MAF is plugged in. I'm 90 percent sure the firing order is correct - but of course I'll check that tonight.

Lets assume the firing order is correct - any ideas what it might be?
 
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DSRacing

Mini Metal MOD
thats for the pointers man - Yeah SOHC.

fuel pressure - we have an aftermarket fuel pump (not sure what type right now - at work). We're getting 40psi when the fuel pump is on (engine off). About 33 when the engine is idling - up a bit during revs, maybe 35 psi.

MAF is plugged in. I'm 90 percent sure the firing order is correct - but of course I'll check that tonight.

Lets assume the firing order is correct - any ideas what it might be?
What kind of fuel filter set-up do you have? You need to have at least a 10 micron filter after the fuel pump to prevent the injectors from getting clogged.

Lastly, did the engine run before you put it in the truck?
 

Igino

Well-Known Member
Is the engine set up with a return style-fuel system or returnless? The returnless system requires about 60 PSI for fuel pressure.
Its return style

When you say the wiring was ripped out and re-done, who did the re-wiring? You may have one or more sensors incorrectly wired.
it was done by the only jerk i know that works for free....me =) I took apart the wiring harness and neatened it up, and with the help of the wiring diagram and a couple of nights, put that bad boy back together one wire at a time.


What kind of fuel filter set-up do you have? You need to have at least a 10 micron filter after the fuel pump to prevent the injectors from getting clogged.
I'm pretty sure we have the right fuel filter, but i'll check. If i decide its not correct, can i take the injectors out and clean them by hand? Will they actually look clogged - or is this an *invisible* problem?

Lastly, did the engine run before you put it in the truck?
Yes - but its unclear how well it ran.
 

DSRacing

Mini Metal MOD
Nevermind about my original question regarding the returnless style fuel system, I thought you were running a SOHC engine not an OHV.

You can clean the injectors by hand. It's not the best way to do it, but it will give you a good idea if the injectors are all gummed up. There is a small screen inside the injector which will tend to capture the larger particles of dirt and debris that enter. Pull one of the injectors out of the motor. Place a paper towel on a table, turn the injector upside down and tap it on the paper towel. There is always a little bit of fuel left in the injector which will flush out some of the dirt. You will see a small ring of dirt left on the towel.
 

Igino

Well-Known Member
you know, its also occurred to me that the engine is actually running decently - and i'm just used to my daily driver chevy tahoe (which puts out a substantial amount more power). Is it possible that after 15 years (as i mentioned its a '94) i'm just not going to be able to get up some steeper hills?
 

Igino

Well-Known Member
OK scratch that last comment - its got to be running crappy - here's why:

Last night I checked to make sure the O2 sensors were hooked up correctly. Of course they were swapped. So i fixed that up and then started monitoring their output signal with a voltmeter. Sensor #2 (drivers side from what i understand) was pegged at .03 volts (running way lean). Sensor #1 (passenger side) kept fluctuating up and down between 0V and 1V. I swapped the sensors and the behavior remained the same, so I assume the sensors are working alright. I did a bit of research and it seems that fluctuating up and down the range is actually the correct behavior, because the PCM monitors how many times the signal crosses .5V to know how the mix is. This would suggest that bank #2 is running super lean. I pulled off the intake and cleaned the injectors on that side, but no luck. Still get the same signals on the voltmeter. Any pointers on where my logic is flawed? Or suggestions on where do go from here?
 
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Wahl_7s

Well-Known Member
Crank some more fuel to it!! More is always better:D It sounds like 35PSI is not enough put 60 to it if you can!
 

Wahl_7s

Well-Known Member
if thats the case, then why would the banks be behaving differently?
I dunno sometimes there's not always a logical answer:confused:It says its lean give it more gas. the only other thing is possibly a vacuum leak. what kinda fuel pump are you running? I run a hella it puts out about 100PSI or so.
 

Igino

Well-Known Member
very possible there is a vacuum leak - is there a good way to test for that? When i pull a cap off the vacuum tree (on the back left side of the manifold) and put my thumb over it, there seems to be good suction. I'm not sure what type of pump we have. I'm pretty sure its works correctly though, cause when we kink the return tube the pressure jumps way up. When the pump is running, but the engine isn't on, we get 40psi, and when the engine is on and idling we get about 33 psi.
 

Wahl_7s

Well-Known Member
very possible there is a vacuum leak - is there a good way to test for that? When i pull a cap off the vacuum tree (on the back left side of the manifold) and put my thumb over it, there seems to be good suction. I'm not sure what type of pump we have. I'm pretty sure its works correctly though, cause when we kink the return tube the pressure jumps way up. When the pump is running, but the engine isn't on, we get 40psi, and when the engine is on and idling we get about 33 psi.
The most common is intake man. but check injector o-rings anywhere air could be getting. Also do you have plastic or steel injector rail check make sure no leaks there.
 

Igino

Well-Known Member
great tip - i'll check that out for sure. we have a steel fuel rail - last night when i pulled it apart and put it back together i didn't notice anything different - so either there is a leak that is so fubar cleaning it didn't fix the problem, or the leak is somewhere else. Come to mention it, i have heard a hissing sound on the left side of the engine, but i'm not familiar enough with engines to tell if it was a air leak, or just the rocker arms moving around.
 

Wahl_7s

Well-Known Member
great tip - i'll check that out for sure. we have a steel fuel rail - last night when i pulled it apart and put it back together i didn't notice anything different - so either there is a leak that is so fubar cleaning it didn't fix the problem, or the leak is somewhere else. Come to mention it, i have heard a hissing sound on the left side of the engine, but i'm not familiar enough with engines to tell if it was a air leak, or just the rocker arms moving around.
check the intake plenum sometimes there are open vacuum ports that have rubber caps on them, maybe one fell off or cracked
 

Igino

Well-Known Member
i'll do that. if i pick up a vacuum gauge, how much vacuum should i expect to see? is that measured in PSI btw?
 

Wahl_7s

Well-Known Member
i'll do that. if i pick up a vacuum gauge, how much vacuum should i expect to see? is that measured in PSI btw?
You know dude I don't know! P.M. Cliff at DSRacing he'll know or he'll have a book that will tell him:)
 

DSRacing

Mini Metal MOD
Sorry, that's one question I don't have an answer for.
 
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