Shop Isuzu Spark Plug Wires

I just bought a 1992 Isuzu Trooper. I seems to run strong with a V6 3.2 liter engine, standard tranny, and over 200,000 miles on it. I have noticed that somewhere on the engine I am hearing an intermittent sparking or snapping sound when the engine is running. Does anyone have any ideas as to what may be causing this? Also my speedometer intermittently works. Does the 1992 use a sensor or cable for this? Thanks for your help.

Can you narrow this down some as noises are tough enough. Electrical noise or some other "snapping" noise is a pretty wide field.


Speedo cable or not. I'd even have to look to see. Electrical snapping is usually high voltage items like secondarys for spark - plugs, wires, cap, rotor etc.


Cables for speedo failures can "whirr" hmmmm or other but wouldn't call that "snapping" ??


T

96
Isuzu
Rodeo
3.2 V6 4X4
135000 Miles


Need to get it smogged (CA)- they said it's an instant disqualification if your check engine light is on.

Symptoms:
-Engine has a very noticible tapping noise- tried all additives- Rislone, Lucas + etc... nothing affects the sound. Did the research and am pretty sure it's the passenger side rocker shaft and exhaust rockers and lash adjusters that need to be replaced to correct the noise... (engine has overhead cams).
-When you first start the engine is lopes heavily almost dieing with every rev... lasts for about 15 seconds then the idle smooths out (engine does not have spark plug wires- it has coils which attach directly to the spark plugs).
-Engine sometimes has a wobble feel to it when raising the rpms.
-A scan of the engines computer revealed the codes:
"P0507"- Idle Control System (RPM high)
"P0300"- Random Misfire Detected
"P0174"- System Too Lean Bank #2
"P0171"- System Too Lean Bank #1

Mainly I'm trying to get it to pass smog, but I'm not sure if the tapping/rocker problem, is causing it to throw codes and make the check engine light come on... I'm hoping someone will be able to understand the codes and tell me if the codes and tapping problems are related- and if so what to do to fix it.

I was told by a friend of a friend (whom I'm not sure is reliable) that it may be the "fuel sensor" that needs to be replaced.

Any light shed would be very much appreciated

With all those codes I would probably be looking for a vacuum leak. It could raise the idle-P0507, kill more than 1 cyl-P0300 and lean out both banks- P0171 & P0174.

Also I'm don't know your situation but there is a CAP program thru BAR that offers assistance in smog repairs, if your are interested I could post you a link.

My buddy has a friend that has a smog shop in your town but I'm not sure if we can refer shops so I'll have to error on the side of caution here............

hey dude I think you were totally right :) lol I decided to go a little macgyver on it and I disconnected my MAF and duct taped up the big hole behind it (leading to the throttle body) and then punched a small hole in the tape and used the compresser to push air through the hole- then I splashed soapy water all over the engine and hoses... I didnt find any bubbles so I was kinda bummed but then I took my head phones out and listened while the system was inflated and then I heard a pretty noticible sound of air coming from behind the engine- at first I thought it was just the sound of the air going through the valve but then when I put my hand behind the engine, I could toooootally feel a tremendous amount of air pouring out of the back near the firewall... I was like- "I'm no mechanic, but I'm pretty sure air is not supposed to come out the back of an engine" lol so I tore the whole thing down and took off whats called the "Plenum" I guess (the big flat aluminum intake part that is over the engine) and low and behold! I had a gasket failure- every contact area was shiny except for right where my hand was at the back of the firewall- it was all dark and grimy (makes me wonder if my valves were damaged) and all busted apart back there (didnt happen when I was removing it). Annnnyway I'm pretty sure this was the monster leak (because like I said- there was a gust of wind basically coming out the back when I pressurized the system) that was causing it to throw "lean" codes and hopefully this will make my check engine light go off :)

oh and thanks for mentioning that CAP program- I tried to get help with that actually and unfortunately they dont cover you if you just bought a car and are trying to get it smogged to get it registered in your name- yeah I know, it's the seller's responsibility- but it was suuuuch a good deal that I didnt mind that he didnt get it smogged- lol most likely this was why he was sellin it lol didnt wanna pay to get it fixed to pass smog.

anyway I kinda think I may have got lucky here- I'm hoping my tapping noise doesnt cause the check engine light to stay on :|

oh and while I had everything off I cleaned out my egr valve pathway, which was waaaaaaaaay clogged with carbon and now I'm cleaning out my idle control valve area (dont really know what I'm doing lol but it's all good)... and I'm also cleaning off my MAF sensor... any other suggestions of stuff I should do while I'm this deep in it? Thanks again guys- REALLY appreciate the help :)

Sounds like you got things under control, good job. I'd replace any marginal looking vacuum lines when your going back together,new gaskets, clean out the codes & drive it so all the moniters run. May have to get it out on the freeway for the cat moniter to run, 20 to 30 miles should do it......

oh my god- it runs 10 times better!! lol no more stalls! :) thanks again for the input- my check engine light is still on though I'm hoping its just because I need to do what you said "clear out the codes"... can you tell me how to do that?

You can check with some of the parts stores, I'm not sure if BAR is letting them do that any more. It keeps going back & forth. You have a Pepboys in your town, they'll do it for no charge or you can disconnect both battery cables & touch them together but that will clear out all learned adaptives as well, so if you get a low idle afterward you will have to clean your throttle body (of course this is something you should've done already so it shouldn't be a problem )

With this having noise and not running properly there is a mechanical part in need to be carefully diagnosed and fixed. When any car isn't running properly it will throw codes that can lead to the area but not necessarily pin point the exact problem.

Same smog stuff here in MA - if check engine light is on it will fail. In fact it has to have been off and running properly for several cycles or won't pass even after a fix! That's for model years 1996 and newer.

IMO - since any additive made no difference a proper diag and fix is in order,

T

Thank you very much for your input :) appreciate your time.

2002 Isuzu Trooper
3.5L Automatic TOD Transmission
192,000 Miles
Idle RPM ~750
Oil Status, definitely needs a change!


Just bought the SUV fairly recently, went 3 days and 150-odd miles with no issues with the car at all, which was good for an as-is no warranty purchase. A lot of problems tend to present themselves early. However, now the car has a bad engine stutter. I was driving home one day and out of the blue the engine started to shake a bit. The only code the car pulls, even while actively stuttering is P0405 which is the EGR Valve.

I've not been able to check much, the car is foriegn to me (only owned vehicles 1966 to 1998) and it is hard to tell left from right in the engine compartment. Too many electronics!

I have the OBD2 diagnostic report if needed.

Update:

Drove it around a little more, still no more codes. It has started doing it more frequently when the vehicle is in idle. So far I have been told it could be---

Spark plugs, spark plug wires, a vacuum line, a bad cylinder, a bad multimeter, a soiled fuel filter, a fuel pump issue, a pinch in the fuel line, and about 4 other things.

Any ideas where I should start based on the issue without codes to help out? Tried taking it to a mechanic and they were going to charge $100 just to diagnose the problem.