Isuzu Mechanic Needed- new problems

[Bigcypresshunter]

I have been trying to repair my 98 Isuzu Rodeo 2.2L 4 cyl, manual trans. all week. It runs but very poorly and has no power. I cannot build up any RPMs. Fuel pressure, plugs and plug wires are good. I replaced fuel filter and plug wires. The fuel pressure tested good at 40 lbs. and fuel regulator tested good too..

My type II scan tool shows 2 trouble codes.

P0342 CMP sensor A bank 1 circuit low input.

P1627 Engine Control Module/Analog/Digital Converter
Probable Cause: Sensor supply wiring or short or module.

I get 12 volts from one wire on the CMP sensor connector and my book says it should be 4-6 volts.
UPDATE: I found that 12 volts to one side and 4-6v to the other side is normal.

Can anybody help please?

 

[Ray S S]

Re: Isuzu Mechanic Needed

Don't know much about these newer cars but in the old days I think the timing would be checked after what you have named
is ok. It could be off slightly.

Ray

 

[Bigcypresshunter]

Re: Isuzu Mechanic Needed

Don't know much about these newer cars but in the old days I think the timing would be checked after what you have named
is ok. It could be off slightly.

Ray

The timing is controled by the PCM (Power Control Module) It picks up signals from the sensors and adjusts the timing as needed. Yes, I believe the timing is severely off but I cannot set the timing. Its not like the old distributers. Thanks for trying to help.

One of the important sensors for timing is the CMP. (Camshaft Position Sensor)

 

[timekiller]

Re: Isuzu Mechanic Needed

Just a thought but could be the converter.I know I've had some in the past clog up and would begin to run with out no power.
My wife now of 19 years had a car one time we and a couple of friends took to charlotte anyway long story short we got out there and it happened to us couldn't even get up to 35mhp on the interstate so I pulled over off the road before we got run down and took the tire tool out of the back and went under the car and knocked or punched a hole in the converter. Got back in fired it up mashed the gas to the floor a couple of times and carbon and crap blew every where. She opened up though and sounded like a dragster but at least I could drive 55 (qoute sammy hager) it would run faster then 55 after a little love and care with the tire iron but I think you get the point.


I would think though if it's getting fire like it should and gas then it could be something just this simple!

 

[DKinPA]

Re: Isuzu Mechanic Needed

I had a '95 that had a bad coil pack....

 

[Bigcypresshunter]

Re: Isuzu Mechanic Needed

Just a thought but could be the converter.I know I've had some in the past clog up and would begin to run with out no power.
My wife now of 19 years had a car one time we and a couple of friends took to charlotte anyway long story short we got out there and it happened to us couldn't even get up to 35mhp on the interstate so I pulled over off the road before we got run down and took the tire tool out of the back and went under the car and knocked or punched a hole in the converter. Got back in fired it up mashed the gas to the floor a couple of times and carbon and crap blew every where. She opened up though and sounded like a dragster but at least I could drive 55 (qoute sammy hager) it would run faster then 55 after a little love and care with the tire iron but I think you get the point.


I would think though if it's getting fire like it should and gas then it could be something just this simple!

I am able to drive 55 but not much more and it takes a long time to get up to speed. The converter is one of the possibilities but my scan tool says the problem is related to the PCM. I hate to replace a $200 converter if its not needed. Thanks.

 

[Bigcypresshunter]

Re: Isuzu Mechanic Needed

I had a '95 that had a bad coil pack....

There are 2 coil packs on this engine so its a possibility that 1 is bad but my scan tool doesnt show a bad coil or any misfires. Thanks.

 

[Bigcypresshunter]

Re: Isuzu Mechanic Needed

I just want to say thanks karenray08, timekiller and DKinPa. Im going to the junkyard tommorrow to look for parts.

 

[Siegfried Schlagrule]

Re: Isuzu Mechanic Needed

Whenever i get an engine code I run it by AutoZone and have them
tell me what is wrong. They do the cheap fixes for free and sell you
the parts or offer to do the work on the expensive stuff. I quit letting
the wife get full service gas because they didn't crank the gas cap down
and I was getting an engine code that translated as gas cap loose. Can't just tighten the cap you need them to clear the error to make it go away after
the repair has been made. good luck, siegfried schlagrule

 

[Bigcypresshunter]

Re: Isuzu Mechanic Needed

Whenever i get an engine code I run it by AutoZone and have them
tell me what is wrong. They do the cheap fixes for free and sell you
the parts or offer to do the work on the expensive stuff. I quit letting
the wife get full service gas because they didn't crank the gas cap down
and I was getting an engine code that translated as gas cap loose. Can't just tighten the cap you need them to clear the error to make it go away after
the repair has been made. good luck, siegfried schlagrule

Thanks. I bought the scan tool so I can test it myself and I can clear it also. Maybe Ill run the codes over to AutoZone but it hard to find anybody that knows this stuff. Thanks.

 

[Bigcypresshunter]

Re: Isuzu Mechanic Needed

Thanks to Blacksheep, who found some online references to a shorted fuel sending unit. My gas gauge has been inoperative for a long time. Here is someone with the same 2 trouble codes. http://www.justanswer.com/questions/1c9tq-my-2000-isuzu-rodeo-4-cyl-5-speed-ran-fine-until-i

I just need to find out where to unplug the fuel sending unit sensor and see if it helps.

The P1627 code indicates an Analog to Digital (A/D) conversion error within the PCM. This code will set if the Fuel Level Sensor 5-volt reference from the PCM gets shorted to ground. The ECM converts the analogue fuel level sensor signal into a digital signal to control the Fuel Gauge, this explains the A/D conversion code. Along with this problem, it is also common to have the cooling fan running, it seems to be a failsafe function of the PCM.

Expert: Tim West
Pos. Feedback: 99.4 %
Accepts: 616
Answered: 8/2/2008

ASE Certified Technician

ASE Certified Service Manager for Bridgstone/ Firestone

 

[timekiller]

Re: Isuzu Mechanic Needed

Just a thought but could be the converter.I know I've had some in the past clog up and would begin to run with out no power.
My wife now of 19 years had a car one time we and a couple of friends took to charlotte anyway long story short we got out there and it happened to us couldn't even get up to 35mhp on the interstate so I pulled over off the road before we got run down and took the tire tool out of the back and went under the car and knocked or punched a hole in the converter. Got back in fired it up mashed the gas to the floor a couple of times and carbon and crap blew every where. She opened up though and sounded like a dragster but at least I could drive 55 (qoute sammy hager) it would run faster then 55 after a little love and care with the tire iron but I think you get the point.


I would think though if it's getting fire like it should and gas then it could be something just this simple!

I am able to drive 55 but not much more and it takes a long time to get up to speed. The converter is one of the possibilities but my scan tool says the problem is related to the PCM. I hate to replace a $200 converter if its not needed. Thanks.

Sure thing Buddy,and hope your able to get it fixed what ever the problem.But to me it sounds like it is starving for air,could be gas though I guess It was just one of the main things to one running propperly.If it will run but acts like it's not got no power it for sure could be.(being it's age)I'm no mechanic by no means but a life of running tractors,on trawl boats,and work in bodyshop dealing with every kind of engine known to man besides jets,and rockets and not being there to see what you are talking about it's all I can tell you.Maybe someone else will come along to help you deside I'm more hands on myself just easier for me that way.
Good Luck,
Take care,
Pete!

 

[timekiller]

Re: Isuzu Mechanic Needed

About the timing part just last year the car we had shreaded the timing belt on it.It was a 4 cyl mazda protege also come to fined out it was supposed to be changed every 60,000miles.Anyway another long story short I had to take all the front pullies off and everything as it was side mounted in the car being front wheel drive but was simple to put the belt on as far as it being lined up.It was just a matter of getting all the marks on the crank and over head valve lined up when you put it on.After that it ran but did act funny but on top the engine there was a nose cone shape electrical adjustment that was mounted like a alternator sits on top of the valves.And I could loosen it and adjust the way it ran while it was running just found the sweet sounding spot.And have never had nomore trouble since.But if this piece works loose it will through your timing off.Not sure how yours is built.Might be another thing to check.

 

[Bigcypresshunter]

Re: Isuzu Mechanic Needed

About the timing part just last year the car we had shreaded the timing belt on it.It was a 4 cyl mazda protege also come to fined out it was supposed to be changed every 60,000miles.Anyway another long story short I had to take all the front pullies off and everything as it was side mounted in the car being front wheel drive but was simple to put the belt on as far as it being lined up.It was just a matter of getting all the marks on the cam and over head valve lined up when you put it on.After that it ran but did act funny but on top the engine there was a nose cone shape electrical adjustment that was mounted like a alternator sits on top of the valves.And I could loosen it and adjust the way it ran while it was running just found the sweet sounding spot.And have never had nomore trouble since.But if this piece works loose it will through your timing off.Not sure how yours is built.Might be another thing to check.

The timing belt has been changed. You may be referring to the CMP sensor. I checked it and it looks good visually but I think its getting an improper voltage signal. . The P0341 code for CMP is not coming up on the scanner. The P0342 code is for the CMP wire or input voltage, I believe. Im just not familiar with these codes but I think its best that I take advantage of them.

 

[Bigcypresshunter]

Re: Isuzu Mechanic Needed

Sure thing Buddy,and hope your able to get it fixed what ever the problem.But to me it sounds like it is starving for air,could be gas though I guess It was just one of the main things to one running propperly.If it will run but acts like it's not got no power it for sure could be.(being it's age)I'm no mechanic by no means but a life of running tractors,on trawl boats,and work in bodyshop dealing with every kind of engine known to man besides jets,and rockets and not being there to see what you are talking about it's all I can tell you.Maybe someone else will come along to help you deside I'm more hands on myself just easier for me that way.
Good Luck,
Take care,
Pete!

It has new air filter. The fuel pressure was tested at 40 lbs. and I replaced the fuel filter. I may hacksaw the converter but I think Ill work with the trouble codes first. Thanks.

 

[timekiller]

Re: Isuzu Mechanic Needed

About the timing part just last year the car we had shreaded the timing belt on it.It was a 4 cyl mazda protege also come to fined out it was supposed to be changed every 60,000miles.Anyway another long story short I had to take all the front pullies off and everything as it was side mounted in the car being front wheel drive but was simple to put the belt on as far as it being lined up.It was just a matter of getting all the marks on the cam and over head valve lined up when you put it on.After that it ran but did act funny but on top the engine there was a nose cone shape electrical adjustment that was mounted like a alternator sits on top of the valves.And I could loosen it and adjust the way it ran while it was running just found the sweet sounding spot.And have never had nomore trouble since.But if this piece works loose it will through your timing off.Not sure how yours is built.Might be another thing to check.

The timing belt has been changed. You may be referring to the CMP sensor. I checked it and it looks good visually. The P0341 code for CMP is not coming up on the scanner. The P0342 code is for the CMP wire or input voltage, I believe. Im just not familiar with these codes but I think its best that I take advantage of them.

Yea Big C,I'm not sure all the codes.This piece I'm talking about though would have a gear on it that locks into the over head cam shaft gear(I think it's dark here right now and can't remember what it looks like for sure) but is a distributor of sorts not like the old ones though as far as how it looks and can control the timing to a degree is controled by it turning which of corse was controled by the timing belt on the main crank shaft being hooked to the cam.It was just another thought as I'm not filmilar with what yours looks like.But being it was a 96 mazda I thought it may be built simiular and was easy to get to on our little car being on top and just one bolt to loose. Anyway I've got faith in yea you'll getter running.
Reguards,
Pete!

 

[RJGMC]

Re: Isuzu Mechanic Needed

When I get a problem that I can't fix or find an answer to, I go to www.automotiveforums.com

In your case search for Isuzu, low power, codes, etc. I usually find the info I need. For any car.

Good luck!

Bob

 

[Bigcypresshunter]

Re: Isuzu Mechanic Needed

When I get a problem that I can't fix or find an answer to, I go to www.automotiveforums.com

In your case search for Isuzu, low power, codes, etc. I usually find the info I need. For any car.

Good luck!

Bob

Looks like a good site thanks.

 

[Bigcypresshunter]

Re: Isuzu Mechanic Needed

I found another reference to the fuel sending unit being the problem. Now that I think of it my cooling fan is always on.. Second article down on right, Joe Wolff. http://www.identifix.com/Corp/posts.aspx

If this is the fix, I would never have figured it out on my own.

 

[Excavator]

Re: Isuzu Mechanic Needed

Trouble codes are part of the diagnostic procedure, but won't always point directly to the problem. How that code and it's component works with the rest of the system has to be considered. Many unnecessary parts have been purchased by folks taking a trouble code at it's word.

Being a bit under the weather today, I'm not as sharp as I could be, but I'll offer this until I can read this post again:

If you suspect a clog in the exhaust system, a quick and simple vacuum reading can verify if that is the case. Here is a very good link on vacuum readings. Vacuum gauges are easy to connect, and relatively inexpensive, around $8-15. The vac gauge is one of the easiest to use, and most overlooked tools in the box.

In short, the vacuum reading will decrease as the engine runs, but read up on the exact procedures. Also note that subtle movements of the gauge can pinpoint other problems. It's a long read, but I could do the test in 5-10 minutes depending on the vehicle.

http://www.centuryperformance.com/tuning-with-a-vacuum-gauge-spg-148.html

And an extra link:

http://www.aa1car.com/library/exhaust_backpressure.htm