'99 ohv 4.0 cam build

[Dono]

Im surprised that you would be running that rich, even if your ecu thinks the motor is cold and its in open loop.

I really don't have any suggestions though.

 

[QueenCitySleeper]

I was thinking possibly bad injector or injectors. Ive gone over all the wiring and vacuum lines. Everything looks fine. Codes point to o2 sensor so Ill go with that for now. And yea Ill keep yas updated.

 

[jd4242]

no I dont have any real gauges. But the smell from the exhaust is nauseous at a stoplight if my windows are open. And i know the analog temp gauge is not great but I figure if it moves the needle that much it is definitely reading a change. What I should do is just re-install the 195 tstat. But your right I should not be trusting the gauge that much. Ill wire up a real temp sensor.

Yea no real need for any lower than 195,that's more for high compression and fi.do you still have cats?was just wonding if you knew exact temps or a/f numbers.

 

[Dono]

sorry buddy, pain in the butt. Yes, you might as well do what the computers telling you to do first.

I cant see an injector either, as the motor would be stumbling on the cylinder having all that gas poured in to it. A vacuum leak would lean the mixture, so thats not it.

JD, wouldn't a tune have to be done if the cats are removed on 1st gen's?

 

[jd4242]

sorry buddy, pain in the butt. Yes, you might as well do what the computers telling you to do first.

I cant see an injector either, as the motor would be stumbling on the cylinder having all that gas poured in to it. A vacuum leak would lean the mixture, so thats not it.

JD, wouldn't a tune have to be done if the cats are removed on 1st gen's?

Only time that a O2 needs to be tuned out is if there is one before and after cats.you won't gain anything by removing cats on a NA motor tho.high flow is good but no cats is bad for NA

 

[QueenCitySleeper]

yea those suckers in the y-pipe are gutted out. I dont see how air makes it through those things. I lost some low end but no doubt it screams when you get above 3500rpm. The only o2 I lost is the emissions one behind the final cat. And its a 2nd gen(1999) if anyone was wondering.

 

[jd4242]

yea those suckers in the y-pipe are gutted out. I dont see how air makes it through those things. I lost some low end but no doubt it screams when you get above 3500rpm. The only o2 I lost is the emissions one behind the final cat. And its a 2nd gen(1999) if anyone was wondering.

What do you mean you lost it?if you had one there and you gut your cats it has to be removed from your tune or it won't run right

 

[QueenCitySleeper]

sounds like my problem is solved. Seems like it runs great. But yea that o2 is no longer there. Only thing behind the y-pipe is the Borla. For some reason I thought I only needed the two that are right behind the manifolds. I didnt think that would affect the tune at all. So does that o2 detect catalytic clogs and blow through? then adjust tune accordingly?

 

[jd4242]

sounds like my problem is solved. Seems like it runs great. But yea that o2 is no longer there. Only thing behind the y-pipe is the Borla. For some reason I thought I only needed the two that are right behind the manifolds. I didnt think that would affect the tune at all. So does that o2 detect catalytic clogs and blow through? then adjust tune accordingly?

I honestly don't know how it works but know if its not there it will throw a code and won't run right.

 

[Runnin'OnEmpty]

..... But yea that o2 is no longer there. Only thing behind the y-pipe is the Borla. For some reason I thought I only needed the two that are right behind the manifolds. I didnt think that would affect the tune at all. So does that o2 detect catalytic clogs and blow through? then adjust tune accordingly?

That last O2 sensor does detect how efficiently the cat
is working, but it's just a 'trigger' for the MIL and a
catalytic code. It's strictly for emissions purposes,
I'm pretty sure, and dosen't affect anything else...

 

[QueenCitySleeper]

Gas mileage has returned to normal. A few things Ive recently done are the K&N drop in with modified airbox, clutch fan delete with e-fan to come for summer, shorter belt to bypass ac comp.,final touches on the bored factory TB, on/off switch for IAC(very cool btw), and for winter running Michelin X-Ice tires on 15's.

these tires go like you wont believe through deep snow, slush, and work like a dream on ice. This is the third winter Ive had them and they are wearing very well even with some aggressive off-roading. They ride very nice and are just slightly noisier than my Michelin MS2's on the highway. I highly recommend them if you encounter snow and ice conditions. Ive never been stuck with them, and Lord knows I try

 

[Xeek]

IAC on/off switch??

 

[jd4242]

IAC on/off switch??

Wondering the same thing?

 

[Dono]

Me 3

Also, any idea what the gas mileaglw thing was about? Thaat was a bad one.
I took a trip to see my parents xmas day at 90 miles/hr. Talking about bad gas mileage...sheesh. Milage was pretty good between 65 to 75 mph though (Probablt around 18). Winter gas doesnt help mileage.

 

[QueenCitySleeper]

The IAC switch is simply a rocker switch wired into the power to the IAC valve. There are two wires. When I cut power to the IAC it returns to a closed state not letting any air by. So you know how a sports car's rpm will drop instantly when the clutch is depressed? Now when I desire I can switch it off to get rid of the hanging idle between shifts. Yea you have to rev match a lot more but it is something different. Around me its all hills. Before when Id coast down a hill at 45mph the idle would hang at 1300. With the IAC switched off it goes to stopped idle speed right away (800rpm). If I dont feel like having that sports car feel or dont feel like rev matching constantly I just turn the IAC back on and it drives like stock. Ill post a video of it in action. It would be very impractical for automatic trans applications though. And on my horrific past gas mileage I have no idea. It now gets around 17-18 city. It still eats gas on the highway, always did even before I installed the comp cam. With yours being automatic and 4wd you cant really expect much.

Here's my IAC switch. Sits right between drivers seat and center console.

 

[Dono]

Nice to see were all getting our issues sorted out.
JD, yiour misfortune is the exception. Im hoping santa was good to you (And, no, I dont mean the 5'5" blonde with the tiny waist and the D cup, either). It would bee great to see you piecing your motor together again.

 

[QueenCitySleeper]

The IAC is a novelty mod but I think it's pretty cool. It's fun to experiment. And yea JD let's see that motor get built. You will be using the OHV still? I sure hope so anyway. and one more thing....

I want a DETAILED list of parts that will be going in the engine. Thanks

 

[jd4242]

The IAC is a novelty mod but I think it's pretty cool. It's fun to experiment. And yea JD let's see that motor get built. You will be using the OHV still? I sure hope so anyway. and one more thing....

I want a DETAILED list of parts that will be going in the engine. Thanks

Yea its still going to be a ohv blockdetailed list probably wont be released

 

[Dono]

What? Hiding details of the build? Nobody is making power with these motors anymore. I understand that there are a lot of guys in your area with explorers, but the 4.0 ohv is going extinct. Those left with them really are not willing to be crazy like us and throw unreasonable amounts of money at them.

Im going to help with your build list:
head studs
Ported and polished heads with oversized valves
forged pistons (you are already intercooling, so boost the crap out of it)
nitrous spray
M112 to get that top end boost up there
what else??? you already have everything.
How much secret could there be left? Im really curious.

 

[jd4242]

What? Hiding details of the build? Nobody is making power with these motors anymore. I understand that there are a lot of guys in your area with explorers, but the 4.0 ohv is going extinct. Those left with them really are not willing to be crazy like us and throw unreasonable amounts of money at them.

Im going to help with your build list:
head studs
Ported and polished heads with oversized valves
forged pistons (you are already intercooling, so boost the crap out of it)
nitrous spray
M112 to get that top end boost up there
what else??? you already have everything.
How much secret could there be left? Im really curious.

Yea but the details are going to be kept for me and my machinists. Its what valves, pistons, rods, pins, bearings. ....etc that is going not be reviled to public.