1994 shuts off when shift into Drive

[kybishop]

Hello all.

My 1994 FZJ80 shuts off when I shift in to drive. It starts up ok and runs good. I have developed a leak in my exhaust at an oxygen sensor and a loping idle at times. I was going to check my idle air control valve and throttle position sensor. Have not done that yet.

We had some floods over spring in Kentucky and my cruiser did not get flooded but was land locked for a while and I did not drive it for some weeks. When I went back to move it, it started up after a jump but shuts off every time I shift into drive.

I shift into reverse and it will engage and stay running. It also feels like it disengages and engages sporadically while sitting in reverse running. It will move.

When I shift to drive it will run for a second then shut off when drive engages. I can move it in drive if I give it gas after I shift it in drive. Not pretty so I don't drive it at all.

Is this something that could be related to my loping idle or sensors or more likely transmission? Sensors or wiring. Bad ground or maybe rodents got to some wiring or vacuum lines?

Transmission fluid is fine. Cruiser was high and dry parked next to our barn. Cows were all roaming around it as they got land locked too.

No codes or check engine lights. I can try to check for codes again anyway and see if anything is there. I have some videos but it would not let me attach them. I need to change file type I guess.

Thanks for any direction here.

 

[kybishop]

I will add that I mention the rodents as we do have a lot of critters being out in the country. Had not had many issues, been there over 50 years. But recently something chewed on our 2016 4runner main and return fuel lines. I had to drop the tank and replace both lines.

Then a few weeks later they chewed my fuel line on my 1998 Jeep Cherokee. Got it at the tank too and also chewed up my vent hose. Squirrel or something, I don't know.

 

[Malleus]

When you shift the transmission into drive, from neutral, it first engages 1st gear, then 2nd gear, then drive. This is all speed dependent, if you never get over 5–mph, you're not getting into drive. Try selecting 2nd start and see what happens.

You definitely have an electrical problem, but it may not be the transmission. It sounds like the fuel pump isn't pumping fuel when the forward gear is engaged, but you need to find out what else is happening, because it probably isn't just one problem. The reverse gear and 1st gear are actually pretty close to the same gear, just turning in opposite directions. [excerpt from the 1994 service manual)

If reverse doesn't bog the engine, 1st shouldn't either. 2nd gear definitely should not.

The transmission shouldn't kill the engine. As a matter of fact, one of the transmission tests is a stall test wher you hold the brake, engage forward gear and try to move the truck forward (this all depends on good brakes, obviously). If the transmission was capable of killing the engine, this test wouldn't be possible.

 

[Malleus]

As a start, if you haven't already done so, I'd suggest you download the 1994 service manual and EWD. They're both in the Resources section, for free download.

The service manual has an extensive transmission section. Unfortunately, there is no troubleshooting step for "transmission kills engine when in drive", so you're going to have to get creative to solve this problem.

 

[kybishop]

Thanks, I am pretty sure I have shifted down from neutral to first and it shuts off as well. But let me try that again to be certain. When I get down there to it I will check this.

Its more like it just turns off than bogs. Not like it's pulling and lugs out. Just is running then boom, like you turn the key off a second after shifting to drive. But, will lurch forward giving gas. But like in reverse it feels like it is engaging and disengaging sporadically. No slipping, just in and out of gear.

Thanks again, this and any information is helpful. I will see what shifting to 1st or second does.

 

[60 toy ota]

From what you're saying it sounds possible you have a bad connection and/or wire that shifts in just the wrong way to kill the engine, and that the shifting is caused by the engine flexing against the motor mounts with the torque of the engaged transmission. An easy way to confirm or bust this idea is to put the transfer case in neutral and then repeat your test. If it doesn't stall in drive with the transfer in neutral, I'd say that's your issue. You would then narrow down on the issue by wiggling the engine harness in various places while running in park.

 

[jonheld]

Another likely issue is a torn intake plenum. The OBD1 FZJ uses similar fuel pump logic to the 3FE.
When the engine shifts on the mounts it could open up the split in the plenum and cause the flap in the AFM to close, shutting down the fuel pump.
The fact that you can keep it running by increasing revs kind of points to that.

 

[Malleus]

Thanks, I am pretty sure I have shifted down from neutral to first and it shuts off as well. But let me try that again to be certain. When I get down there to it I will check this.

Its more like it just turns off than bogs. Not like it's pulling and lugs out. Just is running then boom, like you turn the key off a second after shifting to drive. But, will lurch forward giving gas. But like in reverse it feels like it is engaging and disengaging sporadically. No slipping, just in and out of gear.

Thanks again, this and any information is helpful. I will see what shifting to 1st or second does.

You misunderstood me. When you shift into "D" the transmission is actually in "L" (1st gear). What I'm suggesting is that you select "2nd start" and see if the same thing happens. 2nd gear isn't as low as reverse/1st. My thinking is that if it still happens, your problem isn't the transmission, but a fuel related problem, such as the one @jonheld mentioned to you.

The reason I suggested this course of action is that it's by far the easiest to try and may quickly remove the transmission from the potential root cause list.

 

[kybishop]

Gotcha, makes sense. Thanks.

I put a new rubber intake plenum on some years back as mine was cracked and duct taped and finally just went with a new one. I will check 2nd gear start and check the plenum. Pretty sure I put an OEM one on. I will give a quick look at my wiring, plugs etc for signs of being chewed up or loose.

Thanks all, this gives me some things to check out. I have been absent from the forum for some years, long time member. Just life shifts directions sometimes...

 

[80t0ylc]

You misunderstood me. When you shift into "D" the transmission is actually in "L" (1st gear). What I'm suggesting is that you select "2nd start" and see if the same thing happens. 2nd gear isn't as low as reverse/1st. My thinking is that if it still happens, your problem isn't the transmission, but a fuel related problem, such as the one @jonheld mentioned to you.

The reason I suggested this course of action is that it's by far the easiest to try and may quickly remove the transmission from the potential root cause list.

What you were saying, may be true for later models, but the ‘94 does not have the second gear start. If you put it in 2, it will still start in first gear. I know this because I have had a ‘94 for 25 yrs.

 

[Malleus]

I don't have a '94 with me at the moment; I couldn't remember whether the 2nd start feature was there, or if it was just the ECT (power) override.

 

[kybishop]

Checked a few things.

Intake is all fine, secure and tight. Plenum in good shape.

Shifting transfer case in neutral and then shifting to drive it stays running.

In crawling around underneath while running I did notice an intermittent clicking inside the transmission pan. While idling in neutral it would click and the click would sometimes affect the idle.

This intermittent clicking also coincides with the engaging and disengaging I believe.

I recorded the sound, I will try to get it uploaded. Doesn't sound good though, like internals. It was fine when I parked it.

 

[kybishop]

I didnt see the video I attached. Trying again, for sound.

 

[Malleus]

It may be as simple as the shift linkage being loose. It's an imperfect world, screws fall out all the time.

 

[Mandrake]

Try selecting 2nd start and see what happens.

I thought 2nd gear start was only available on the A343F trannies?

 

[Malleus]

I thought 2nd gear start was only available on the A343F trannies?

It is, by pushbutton. It can be done on the A442F, but not from the driver's seat.