Need 4.0 HELP!

[Wellmud]

I have a 96 ranger 4.0 5 spd., last week the engine started idling rough, it would speed up then drop back and start surging again and sometimes die. I went to autozone and checked the engine light codes and they came upO171 and PO174 which is right and left bank too lean, their book said it was the MAF. I thought I would try cleaning it before buying one, after cleaning, it actually ran worse, rough loping idle, at higher rpm it smooths out but while driving it will only idle back to about 1500 rpm and sometime hangs between 2-3000 rpm. So today I went to NAPA and bought a new (rebuilt) MAF and it made no difference. Any Ideas? Please help.

 

[289-tiger-]

I have a 96 ranger 4.0 5 spd., last week the engine started idling rough, it would speed up then drop back and start surging again and sometimes die. I went to autozone and checked the engine light codes and they came upO171 and PO174 which is right and left bank too lean, their book said it was the MAF. I thought I would try cleaning it before buying one, after cleaning, it actually ran worse, rough loping idle, at higher rpm it smooths out but while driving it will only idle back to about 1500 rpm and sometime hangs between 2-3000 rpm. So today I went to NAPA and bought a new (rebuilt) MAF and it made no difference. Any Ideas? Please help.

Check and clean the connector to the MAF, battery disconnected. On earlier models the OEM manufacturer supplies a new connector with its MAF (resistance issues). Also check all the basics.

Good luck

 

[ranger1999xlt]

You can also try cleaning or replacing your IAC "Idle Air Controler" Valve. Which is located on the top by the intake. The can be your idle problem. Those are a common problem on all three engines on the Ranger. A bad or "dirty" one can cause your engine to idle high. Hope this helps.

 

[nitrofan1]

This web site has been very helpful to me in the past on other vehicles besides my 94 Splash. It has a lot of info including message boards. Cleaning the MAF with the wrong chemical will cause a malfunction too. Try this site and see if they can help. Also, NAPA sells the brand which is actually Neihoff parts and are good. Borg Warner is another good brand but forget the Auto Zone stuff. Wells ignition is junk plain & simple. Course you can't go wrong with Motorcraft OE stuff!

Here's the web site: http://www.obd-codes.com/

Hope this helps!!!

 

[rangerrager]

start looking for a vaccum leak buddy.if the maf doesnt fix it chances are thats where the problems lies

 

[rangerdude91]

i just had the same problem with mine. where the black intake is on the driver side there is a pipe thats fat at top and gets skinny. it runs down near the exhaust. anyway were it connect to the black intake make sure that its sealed because mine did the exact. go and scrap the old gasket maker off and go get the RED RTV at like autozone. put it on there and let dry and apply it again. DO NOT START WHEN WET! it will suck it in.

ps if you here a high pitch noise it is that for sure. put your finger next to it and see if you feel the suction

hope that helps

 

[rangerdude91]

oh mine read the same. i dont think its the censor

 

[Wellmud]

Thanks for everyones help. I used the CRC MAF cleaner and also cleaned the terminals. I went to Auto Zone to let them read the check engine codes, that was before I realized my tuner for my F350 would also read the codes, it said the same thing, right and left bank too lean. I bought the MAF at NAPA and didnt cure the problem, $120.00 down the drain. I know a vacuum leak will cause rough idle, but would it show r/l bank too lean? Not sure exactly what the part is called, the little flat round can behind the AC comp. and PS pump that is mounted on a pipe coming off of the exhaust manifold, I noticed it has a 1/4" size round hole in the side that is leaking exhaust, but I can hold my finger over it and it doesnt make any difference.

 

[289-tiger-]

Vacuum leak or anything passed metered air could give you a lean reading or a rough running condition.

Good luck

 

[Wellmud]

RANGERDUDE91,
Are you talking about the steel pipe that comes out of the black plastic on the lower front drivers side of the intake? Mine seems tight and doesnt seem to leak.

 

[rangerdude91]

yeah. mine wasnt really loose but the material around it had worn away and all i did was scrape it off and seal back up. mine did the exact thing and it fixed it just how it was before which was perfect. start the engine and put you finger around the whole thing

 

[wahlstrom1]

The gasket between the upper/lower intakes to the fuel rail inbetween are common area's for a 4.0L to get a vacuum leak. Take an unlit propane torch and run it up and down the intake with the truck running. When it revs up, you know where your leak is, ether can also be substituted for propane, but when you find the leak try not to spray it too much.

-andrew

 

[Wellmud]

I've only had the truck 2 weeks, so I'm only just figuring out what some of the components are. Are you talking about using the propane to check the gasket where the black plastic intake bolts down?

 

[wahlstrom1]

Yup, and below it as well.

-andrew

 

[Wellmud]

Ok, this morning I tried looking for a vac. leak with propane and could'nt find any. I had 2 more DTC codes come up: P1131 and P1151=Lack of HO2S11 & HO2S21 switch sensor indicates lean. My EGR valve is leaking exhaust, on the flat boss on the under side, there is about a 1/4" and a 1/8" hole side by side, they are blowing exhaust out, it looks like something is missing from the holes, not sure as I dont have another one to look at, any ideas?