94, V-6 engine cutout @ 2400+rpm only

ozarkian · Nov 30th, 2012, 07:00 AM

I have posted this question on another thread, but was kicked off. so for all of you V-6 owners, here we go again!

1994 SE V-6 4X4. She starts and runs with only this one quirk. It is costing me fuel economy and performance. I live in the Ozark Mountains so there is alot of uphill driving, and shifting gears. Therein lies the problem.

Every time the rpms drop down to 2400 the engine lugs and vibrates, untill you get the rpms back up above 3000.

This happened last year about this same time. But after poking around and running a few cans of fuel treatment through her it cleared up until last month.

Here is the list of what I have tried thus far: Wiggle and jiggle all wires and
harnesses and connectors.

New Throttle postion sensor
new spark plugs
several cans and brands fuel treatment
check codes. just knock sensor. Duh!
check all vacuum lines, replaced ends of some.
ALOT OF CURSING!!!

So, I am hoping some of you folks have had a similar problem with your V-6 and can shed some light.

A search of the forum turned up a similar problem but with a much older engine. Sooooooo.

thanks folks
crystal

zanegrey · Dec 11th, 2012, 12:35 PM

TAKE THE BAT CABLE LOOSE AND RE READ THE CODES..

STOP USING THAT TREATMENT STUFF.

CHECK AND OR REPLACE THE COOLANT TEMPERTURE SENSOR..

ozarkian · Dec 11th, 2012, 05:15 PM

zanegray, thanks for the reply. I did what you suggested with the Battery cable and got the "no malfunction" code. I will do it again, after driving this weekend.

Why stop using the treatment??? Curious?

Cooland Temp. sensor??? How will that help?

Here is a new thing I noticed, When I start the truck after is has sat for awhile, I notice a fuel smell. There are no leaks. But it seems to be dumping or not burning gas
on start up.

Ideas?

zanegrey · Dec 11th, 2012, 07:08 PM

1 OR 2 TREATMENTS OK .. N E MORE U R JUST THROWING MONEY AWAY.

TEMP SENSOR CAN CAUSE THIS AFFECT..

ozarkian · Dec 11th, 2012, 08:17 PM

Sounds weird, but I will try.

Now, this is the same temp sensor for the water/engine temp??

thanks

SPEEDO · Dec 12th, 2012, 08:34 AM

there is one that feeds the gauge(single connector), and one that feeds the ecu(injector style connector)

ozarkian · Dec 12th, 2012, 01:09 PM

Ok Boys. Which one am I looking to replace???

crystal

SPEEDO · Dec 12th, 2012, 03:40 PM

The one that feeds the ecu (oem pt# 22630-51E02)

Erics_Daily · Dec 13th, 2012, 01:15 PM

Does it do it regardless if its a cold engine or warmed up?

ozarkian · Jan 27th, 2013, 09:57 PM

Quote:

Originally Posted by SPEEDO

The one that feeds the ecu (oem pt# 22630-51E02)

ok speedo, it is starting to make a little more sense to me now. MY question was more , which sensor as in where on the engine.

I am begining to see the light a little. Let us look at the evidence so far,,,

I had this same issue about the same time last year. Weird, but ok.

There is a fuel smell on cold morning start ups.

It lugs under a load after changing gears, and starting from a stop.

This reminds me of a carb with the choke stuck closed or partially closed.

So do you think the temp sensor is telling the computer that the engine is cold all the time and it is pulsing too long or sending too much fuel through the injectors so I am getting a fuel "dump"or too rich type of situation??

Or,,,, is the evidence just circumstancial and we are making it fit the symptoms???

PLEASE HELP ME OUT GUYS!!! THE EXTRA FUEL AND THE VIBRATIONS ARE KILLING ME.

ALL THIS BRAIN POWER AND WE CANT FIX IT?????

veesix · Jan 28th, 2013, 08:12 PM

My truck has lasted forever, by driving slower. Ease it around, and enjoy life. The thing might not be running perfect. but it will continue on like that (running) forever.

Mine is an 88, so you might have the more modern fuel induction system. I would start going through it and make sure that everything is clean. Consider that about 75 bucks a month in maintenance is very cheap transportation. If you have to spend 800 bucks on new injectors (for example) you will be back to even money after maybe 10 months.

Air filters, air flow sensors, injectors, o2 sensors, distributor and ect.. All this stuff is cheap enough and you won't regret having new parts. Clean and replace, and slow it down for awhile and enjoy life.

**smj999smj** · Jan 28th, 2013, 08:44 PM

Since it appears that the engine is running rich, the first thing I would do is check to make sure the vacuum hose is attached to the fuel pressure regulator at the back of the engine and then test the fuel pressure with a fuel pressure gauge to make sure it is within specs and not excessive. Also, make sure the coolant gauge needle is about in the middle when the vehicle is at normal operating temperature. If it is sitting at the lower end of the gauge, near the "cold" range, you may have a thermostat stuck open that needs to be replaced. If all is good at this point, definately look at the ECT sensor and make sure it is reading correctly and the circuits are good.

ozarkian · Jan 28th, 2013, 09:59 PM

Thanks for the replies.

I have checked the vacuum hose. It is good. I don't have a fuel pressure guage.

I am just a lady who like to work on her own stuff. I have been messed with too much at auto shops. Shops will quote me one price, and my brother almost half as much for the same work on the same truck!!

Anyway, I am planning on replacing the thermostat this weekend, and perhaps even the water pump as well.

I have to replace the crank oil seal cause it is almost pouring oil out of the lower timing cover. Since I will be right there with the radiator, shroud, fan, belts pullies, etc. all pulled out, I may as well put all good stuff up there so I won't have to worry about it later.

I was thinking on replacing the temp sensor as well.

BTW. what is the other wire go to right there with the temp sensor???

Thanks. I will let you know.

Not much on taking it slow and easy. Plan on doing 90mph sliding to a screeching halt and yelling "what a ride" into my grave!! LOL

Crystal

**smj999smj** · Jan 28th, 2013, 10:46 PM

If it's a single wire switch, it's likely the temperature sender for the coolant gauge. A fuel pressure gauge might be available through a loaner program from your local parts store. Simply tees in between the top of the fuel filter and the fuel filter hose. Turn the key "on," and you'll see the pressure raise on the gauge. Start the engine and it should be around 34-36 psi. Disconnect the vacuum hose from the fuel pressure regulator and plug it off, the pressure should raise up to somewhere around 45 psi +/-. If the "regulated" pressure is higher than 36 psi, you may have a lack of vacuum to the regulator, bad regulator or a restricted return fuel line. Excessive fuel pressure will push more fuel through the injector than should, causing the engine to run rich.
If you are doing a water pump, check out the "Gates Timing Componant Kit w/ Water pump" at Rockauto.com. It gives you the timing belt, water pump and tensioner along with instructions and a mileage sticker. Good quality parts at a very reasonable price (and usually a lot cheaper than what you can get the same parts for at the local auto parts store or dealer). I use them a lot on the VG engines. I would recommend you get the front cam and crank seals, as well as the thermostat, from Nissan. If you are replacing drive belts, I would get them from Nissan, as well.

ozarkian · Jan 28th, 2013, 10:59 PM

good info. Thanks.

I will check with the parts store about the pressure guage.

Why Nissan on the seals and belts?

Is there that much difference in the seals? the belts?? Gates have always been pretty good belts.

Just curious.

crys.