Strange problems w/ the vx

[Ruflyf]

Well I havent really found any solutions to my problem. So unless anyone has any info looks like I'll have to start changing out random parts.

Here are the symptoms:

1) While driving normally, (sometimes) I'll get what feels like a little miss in the drivetrain, it immediately goes back to driving normally. No trouble lights come on when this happens.

2) While driving normally (sometimes) the vx will downshift, causing the rpms to jump up to 5kish. When this happens several trouble lights come on (a/t temp., winter, power). Out of reflex, I release the gas pedal and after 1-2 secs the tranny goes back into the correct gear and the trouble lights go out.

I have just recently replaced the tranny fluid and filter to eliminate it as being a possible cause. The next step is to remove the interceptor just to eliminate it as being a possible cause. Other than that, its replacement time


Other things that may be related. (NOTE: These following issues have been addresed in other posts, so I'm not looking for info on them directly, just wanted to mention them in case someone thought they all might be related.

As mentioned in a different post, my tach is jumping around. Its acting similarly to the old style speedometer cables when they started stripping out. Since there is no seperate tach sensor, I dont know whether its the comp causing this issue or maybe the guage itself.

Also as mentioned in another post, my ABS light comes on after driving a couple miles and then stays on til the vehicle is turned off.


P.S. Thanks for all the posts on similar topics I have left, I am not trying to sound like I am looking for other opinions, just wanted to combine the issues into one post.

[Joe_Black]

Definitely remove the Interceptor and reset your ECU (30 minutes battery disconnect) as more and more Interceptor failures are popping up on various forums.

Have you pulled a code history from your ECU?

[Ruflyf]

No i havent Joe. Trying to decide if i wanna tackle pulling the interceptor here at work today or not lol.
I'll do the reset after I get the interceptor pulled, dont know if it would reset differently with or without the interceptor in place but better to be safe than sorry.

[Joe_Black]

The Interceptor shouldn't affect the reset of your ECU at all, but I don't know if the Interceptor has any type of non-volatile memory in it. There certainly isn't any way it could re-program the ECU, as its only purpose is to modify transmission telemetry.

[Ruflyf]

Well got the interceptor pulled and the battery reset. Didnt get a lot of driving time over the last couple days but I havent felt any stumbles or irregular downshifting. So (crosses my fingers) hopefully that problem is fixed. Wonder if the interceptors have a warrenty, probably not.

I do still get the ABS light that comes on after driving it a few miles. I noticed the TOD lights will flash occasionally which lights up the ABS light.

[Ruflyf]

Well my last reply was a bit premature. Seems that its still downshifting occasionally, however it does seem less often (probably my imagination). Gonna get any codes that might be present read today and go from there. I do think the interceptor is fine now though. Just figured I'd keep this issue updated for future use by others.

[Joe_Black]

Sorry I didn't think to add this earlier, but have you double-checked the tranny fluid level? I know it's a pain, but a good thing to do a little while after a change.

[Tone]

There is a one year warranty on the Interceptors and I have had exactly 2 fail (well one, the other melted on the exhaust pipe) in the four plus years I've been using them. The Interceptor IS designed to increase the shift firmness both up AND down and if IT is set improperly, can damage the transmission hard parts. "More and more Interceptor failures popping up on various forums" - must be like the VX becoming a collector's item rumors - I hear it all over the web!

[Ruflyf]

Tone-----I agree, I am actually glad the Interceptor is not the cause because I like it.

Joe-----I have not rechecked the fluid, and yes I agree I need to get that checked still. I still get the feeling (backyard mechanic) that nothing mechanical is wrong (major parts anyway). I cant explain it, just a gut feeling. I get the feeling its electrical or vacuum related, of course thats assuming the tranny fluid checks out.

[WormGod]

I had some minor issues with the Interceptor and removed it. Used it for damn near 3 years and loved it. Made a small, but noticable difference. I started getting some shift lags and downshifting started getting rough, so I removed it. SHifting was back to being smoother once removed. After further inspection of the module, it was pretty war-torn from road wear. I suspect being open to elements (tie fastened to frame) for some time may have caused some issues for it. Winters with rock salt and sand, as well as rain and high heat in other months of the year (basically, east coast seasons) are probably not gonna mesh well with prolonged exposure with the module.

Just a guess in my case since the module was pretty rough looking.

[Ruflyf]

Ok, this makes absolutely no sense to me but, I am glad to say the problem seems to be resolved. I feel a little relieved, aggrevated, and stupified all at the same time.

It seems the problem was something I had problems with in the past. Basically it boils down to the EGR. In the past I have had problems with the bottom (22m) nut coming loose due to vibration, well this caused no noticable problems except the slight exhaust leak sound while driving. I was out driving the other day and noticed the same exhaust sound I had heard in the past (at this time is still have the erratic rpm guage, abs light, occasional downshift, and engine stumble) so I decided to pull over and tighten the bolt, since I learned from past experience to carry the required 22m stubby with me. Much to my suprise I noticed the 2 allen bolts for the pipe between the egr and the s/c were also loose at the EGR block. Unable to tighten these out on the roadway, I drove home with them loose still (with the same problems I had been having). Soon as the engine cooled off enough I tightened them back up. Well its been 4 days later and everything is completely back to normal, no erratic rpm guage, no abs light, no downshifting, or stumbling.

How a simple air leak can cause soo many different issues, I'll never know, but I am glad it was an easy fix. Just wanted to let everyone know, if any of the symptoms are ahowing, check the EGR fitting closely.

[Joe_Black]

How a simple air leak can cause soo many different issues, I'll never know

It just freaks the sensors out and the ECU simply isn't the smartest thing in the world. Get outside of its computational box and it'll torture your engine trying to rid itself of the demons it thinks it "sees".

Thankfully I've never had an EGR issue with any of my Isuzus, but I almost wish I would just as an excuse to remove the EGR and replace with some block-off plates and an EGR simulator.

Actually, my plan is to use MegaSquirt for the rally VX which could possibly open up a whole new realm of possibilities for everyone interested in taking control of their engine management.

In any case, hopefully this resolves your issues and you can just button those fasteners up with some HD LocTite and drive happy.

[JHarris1385]

So this screw is directly underneath the egr? I think this is my problem too. My truck if not normally supposed to sound like this, sounds more diesel iv noticed......

[Ruflyf]

The bolt that is 22m is under the EGR block. The 2 hex nuts are on the engine side of the block that the EGR attaches to. The lower bolt just caused a exhaust leak sound. The other two hex bolts being loose caused all the other issues.

So this screw is directly underneath the egr? I think this is my problem too. My truck if not normally supposed to sound like this, sounds more diesel iv noticed......