Eng. turns off while car is being accelerated!

97/ ROdeo/ 95 k miles Eng. turns off while car is being accelerated, then turns right back on, but i have to turn it back on. Problem started 3 and half weeks ago, one week after a tune up.I switch gas filter, bosh spk plugs, EGR, and the pcv. I took it to the dealer (thinking they'd be the best) and they dont know whats wrong with it, but want to charge me $800 to change my IAC, decarb the engine, and change the spark plugs, but my spark plugs are new and my car doesn't turn off on idle, only while its being accelerated. They did charge me for the diagnostic. No codes are recorded in the computer, I switched fuel pump relays, checked the battery cables and cleaned the wires, and its not the ignition switch. I took it to Sundevil and they couldn't diagnos it either, but they were decent enough not to charge me. :banghead: I 've read all the posts on this forum and havn't read about any problem similar to mine, I really like my Rodeo its been in my family since 98. I can afford to get it fixed, I cant afford a new car. However, I dont want a new car, I have already invested on new belts all around , spark plugs, water pump, new EGR, brakes, and I had it transported from NEW YORk to Arizona where I now live, go to school, and work. And Arizona is so perfect for off roading and now this problem occurs. I 've had Four mechanics look at it, its definitely electrical, what do you guys think. Your my last council:uhoh:

I'm assuming you have the 3.2L V6/automatic??

Check all of your ground connections, and double check to make sure that alternator's in there good and tight, and that it's pulling enough charge. If it's original, it may be weak enough to cause issues - these trucks will act very strange when low voltage occurs.

Are you getting gas at the same gas station - if so, switch to a different brand. Just out of thought -my Rodeo did the same thing as yours a year ago, three times on thie highway doing 65, switched gas stations later that day, ran flawless afterwords.

I'm not 100% fond of Bosch spark plugs, I did run a set for nearly 70k miles without issue in my '97, have since put in NGK's. Also, make sure that everything in this area is good and tight too, and double check for any torn/cracked spark plug boots.

Could be the IAC valve too, in which you may be able to clean that and/or replace that yourself. I haven't had an issue with that yet, so I'm not sure what the symptoms are.

Keep us posted - btw, I have 173k miles on your same truck/engine, it is worth trying to find the fix, you'll get MANY more miles out of it.

Will it do it under hard acceleration moreso than gradual accel? I'm wondering if the movement in the drivetrain puts tension on a wire or causes rubbing/contact.

Yes it is the 3.2L V6.I'll check the ground wires and such this weekend, the alternator is fairly new a little over a year old.My mechanic from back home told me it could be a gas issue, so he recommended I put Lucas injector cleaner and I used HEET water remover, to clean out my gas tank, I poured both in together, Im thinking of doing it again. I use random gas stations Cirlce K, CHevron, SHell.Spoke to my DAD yesturday, whom I inherited the Rodeo from and he said he always put BOSH PLTNM in the car also, I cant really spend another 100 bucks on a new set-not yet anyway, but I will double check for any torn/cracked spark plug boots. ANd MAKE SURE ITs tight-for sure.I have spoke to a group of Techs all state the IAC would only come into play if it the eng. shut off during idleness, but I should clean it anyway.I will definitely keep this site posted, with the problem, incase this happens to any other Rodeo- I am determined to keep my Rodeo and solve this mystery. I was just getting ready to invest in lifting the RODEO and add some 30 inch tires and go into deathvalley and Sedona off roading, I guess theres always next year.97 Rodeo 3.2L V696 000 miles running around till it DIES!

Will it do it under hard acceleration moreso than gradual accel? I'm wondering if the movement in the drivetrain puts tension on a wire or causes rubbing/contact.
I would say moreso under Hard acceleration than Gradual, but this morning it occured once on my way to work and my acceleration was totally Gradual, but I will admit I have a heavy foot on the pedal.Thanks for the replies, I appreciate all the info I can get.

FWIW - no need to put in new spark plugs unless you're finding an issue with the plugs you have, otherwise, this engine WILL run with the bosch plugs, as long as there's no defect in the one's you have.

also, your truck can safely run up to a 32" tire without a lift, I'm running LT265/75 R16 8-ply tires on my Rodeo without issue. I have no lift.

Have you checked fuel pressure, or changed your fuel filter - could be clogged.

My truck runs best on Shell gas, any where else, for what ever reason, does not deliver as good of power or gas mileage.

I'll check the plugz, but really wasn't planing on changing thm ($!).Thats cool info concerning the tires. Didn't know. Thanks!The fuel filter is new, ill get the fuel pressure checked anyway...

I notice the alt was changed in the last year. Where did it come from?

I notice the alt was changed in the last year. Where did it come from?
Auto Zone.

Uh oh.

Auto Zone.

:nono: :nono: :nono:

:popcorn:

Your truck's probably eating it up and getting ready to spit it out!

Isuzu's generally prefer alternator's from Napa, Bosch or OEM quality; most other reman alt's are put in as breakfast, and spit out at dinner time.

FWIW - no need to put in new spark plugs unless you're finding an issue with the plugs you have, otherwise, this engine WILL run with the bosch plugs, as long as there's no defect in the one's you have.

also, your truck can safely run up to a 32" tire without a lift, I'm running LT265/75 R16 8-ply tires on my Rodeo without issue. I have no lift.

Have you checked fuel pressure, or changed your fuel filter - could be clogged.

My truck runs best on Shell gas, any where else, for what ever reason, does not deliver as good of power or gas mileage.

Thanks for the tip; Im gonna get the alternator/rodeo checked out now, and repost when done.


Oh 1 more question for Ramblin fever, does the 32 inch tires rub at all,
Find it hard to believe theres no rubbbbbbbing

Oh 1 more question for Ramblin fever, does the 32 inch tires rub at all,
Find it hard to believe theres no rubbbbbbbing

One question for you, can you post a pic of your wheels? Or describe them to me, i.e. oem steel wheels or aluminum?

My OEM wheels were steel, 16x6, in which the 32" tires rubbed a VERY slight tad, not even enough to be concerned; the ONLY reason I went to wider rims was because the 265 width was crowning badly on the 6" width rim.

However, on the 16x8 rims that I have now, there is absolutely NO rubbing at all with the exception of the front mudflaps which I have figured a way to pull the top of them back far enough that it's no longer an issue - I had taken them off for a time, but found I was getting bad rock pits on the underside of the doors due to the tires.

If you have 16x7 aluminum OEM wheels, there is NOTHING to be worried about, put the tires on and be happy.

I have taken this truck on a few fairly wicked/rough trails since putting these tires on 2yrs ago, haven't had an issue yet.

My truck is completely stock with the exception of heavy duty shocks front/rear.

What I would do, though, if you have an automatic, is be sure to change your tranny fluid (partial changes) at least every 15-20k with running bigger tires.

Bosch Platinums usually don't work well with waste spark ignition systems like whats on Rodeos, Saturns and other vehicles.

OK, Sorry I took so long. Got the alternator checked out-its fine. Not the problem, I did install a brand new delco battery, but the problem continues, at this point, im gonna chill and wait to get some cash and change the plugz in a week or so. Still clueless as to whats the problem.

Bosch Platinums usually don't work well with waste spark ignition systems like whats on Rodeos, Saturns and other vehicles.


What do you mean a "waste spark ignition" system like what's on Rodeos?

I am really curious.

cleaned the IAC, might change it next week, added some new hoses, but problem still continues, Im thinking of changing the oxygen sensors, and will continue changing till engine stabilizes< i was also told to decarb the eng., so Im gonna get a gallon of racing gas and through into the gas tank, Keep yall posted a.s.a.p.

What do you mean a &quot;waste spark ignition&quot; system like what's on Rodeos?

I am really curious.
Hope this helps you understand it a bit:The first systems appeared on the Buick 3.8-liter V6 in 1983. Today, DIS is mainstream technology, appearing on most new models introduced in the past decade. Direct (distributorless) ignition systems can be classified as being one of two types-individual-coil systems, with a separate coil for each cylinder (often called "coil-on-plug" designs), or waste-spark systems, which use one coil for every two cylinders. Individual-coil systems are used by some Asian and European carmakers and on an increasing number of domestic models. The DIS installations on most GM, Ford and Chrysler engines built in the past 15 years, however, are the waste-spark type.An ignition system in a four-stroke cycle internal combustion engine may fire spark plugs in pairs, on both the exhaust and compression strokes. The extra spark on the exhaust stroke has no effect and is thus "wasted". This design is simpler than a conventional ignition system, but the extra sparks reduce the lifespan of components (contact breaker, spark plugs).Many single cylinder 4-stroke engines also have a wasted spark. There is only one spark at a time, but at twice the rate that is needed, so half are wasted. The magneto on these engines is on the flywheel, so there is a spark on each revolution of the engine, but the cylinders on 4 stroke engines only fire every second revolution.Retrieved from "http://en.wikipedia.org/wiki/Wasted_spark"A waste spark is the spark that occurs 360° from the “normal” spark that fires the fuel mixture. Remember the “normal” spark occurs every 720° (2 turns of the crank shaft). The spark plugs are fired directly from the coils. The spark timing is controlled by an Ignition Control Unit (ICU) and the Engine Control Unit (ECU). The distributorless ignition system may have one coil per cylinder, or one coil for each pair of cylinders. Some popular systems use one ignition coil per two cylinders. This type of system is often known as the waste spark distribution method. In this system, each cylinder is paired with the cylinder opposite it in the firing order (usually 1-4, 2-3 on 4-cylinder engines or 1-4, 2-5, 3-6 on V6 engines). The ends of each coil secondary leads are attached to spark plugs for the paired opposites. These two plugs are on companion cylinders, cylinders that are at Top Dead Center (TDC) at the same time. But, they are paired opposites, because they are always at opposing ends of the 4 stroke engine cycle. When one is at TDC of the compression stroke, the other is at TDC of the exhaust stroke. The one that is on compression is said to be the event cylinder and one on the exhaust stroke, the waste cylinder. When the coil discharges, both plugs fire at the same time to complete the series circuit. Since the polarity of the primary and the secondary windings are fixed, one plug always fires in a forward direction and the other in reverse. This is different than a conventional system firing all plugs the same direction each time. Because of the demand for additional energy; the coil design, saturation time and primary current flow are also different. This redesign of the system allows higher energy to be available from the distributorless coils, greater than 40 kilovolts at all rpm ranges. The Direct Ignition System (DIS) uses either a magnetic crankshaft sensor, camshaft position sensor, or both, to determine crankshaft position and engine speed. This signal is sent to the ignition control module or engine control module which then energizes the appropriate coil. The advantages of no distributor, in theory, is: No timing adjustments No distributor cap and rotor No moving parts to wear out No distributor to accumulate moisture and cause starting problems No distributor to drive thus providing less engine drag The major components of a distributorless ignition are: ECU or Engine Control Unit ICU or Ignition Control Unit Magnetic Triggering Device such as the Crankshaft Position Sensor and the Camshaft Position Sensor Coil Packs