Isuzu Mechanic Needed- new problems

Re: Isuzu Mechanic Needed- problem still not solved

Every thing I am hearing is the timing is wrong. You are going to have to check that timing belt. You might possibly do this by using the timing mark and pulling a valve cover to see were the valves are at TDC during the cycle.
TDC can be found by pulling a plug and finding when the piston is at the top of the crank shaft. A lot of modern systems are not marked on the balance wheel so once at TDC you can mark the balance wheel.

If it is not this it could be the computer and or sensors.
 

Re: Isuzu Mechanic Needed- problem still not solved

the reason the EGR doesn't show a code is because the EGR is totally mechanical.
EGR stands for Exhaust Gas Recirculation, it's an inexpensive fix. if you have a lot of miles on it
it could be plugged, which if plugged long enough can create other problems
 

Re: Isuzu Mechanic Needed- problem still not solved

Thanks for the ideas. Im working on it.
 

Re: Isuzu Mechanic Needed- problem still not solved

HI: an EGR valve inexpensive??? My Trooper's cost $250 US at the Isuzu dealers. Drivers side, rear vision mirror, which was scragged by someone, will cost $500 Us. Sigh

Don Jose de La Mancha
 

Re: Isuzu Mechanic Needed- problem still not solved

Real de Tayopa said:
HI: an EGR valve inexpensive??? My Trooper's cost $250 US at the Isuzu dealers. Drivers side, rear vision mirror, which was scragged by someone, will cost $500 Us. Sigh

Don Jose de La Mancha
You know the dealer is the most expensive place the buy. Im sure I could get them for 10-20 bucks at my U-pull-it junkyard.
http://www.u-pull-it.com/
The exhaust manifold is $17 but I cant find it. Ill have to buy it from eBay at $85 new which is still a good deal they tell me.

Click on price list.
http://www.u-pull-it.com/

I had to modify this 6 times to get it to post the links properly. Very aggravating. I wish TN could fix this problem unless its me. Mirror and EGR both under $10 used. http://www.u-pull-it.com/
 

Re: Isuzu Mechanic Needed- problem still not solved

if you send me the specs on your manifold, I can see about getting it here
 

Re: Isuzu Mechanic Needed- problem still not solved

I checked with a buddy of mine, it looks like the one online is going to be cheaper. while he did have on for 70.00
shipping would easily eat up the savings to ship it from here, even if it was across the street, sorry
 

Re: Isuzu Mechanic Needed- problem still not solved

Sniffer said:
I checked with a buddy of mine, it looks like the one online is going to be cheaper. while he did have on for 70.00
shipping would easily eat up the savings to ship it from here, even if it was across the street, sorry
Im ordering the new manifold from eBay as soon as I find out how quick he can ship. I sent him an email. I hope he can get it here by Monday. Thanks anyway. I checked around and its a good price. http://cgi.ebay.com/ebaymotors/98-9...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

The only places cheaper are the pull it yourself kind and I cant find it.
 

As an eBay Associate we earn from qualifying purchases.
Re: Isuzu Mechanic Needed- problem still not solved

Sniffer said:
the reason the EGR doesn't show a code is because the EGR is totally mechanical.
EGR stands for Exhaust Gas Recirculation, it's an inexpensive fix. if you have a lot of miles on it
it could be plugged, which if plugged long enough can create other problems
I know what EGR is. My EGR appears to have wires going to it. The reason Im asking is because Im an old-time mechanic and Im not familiar with diagnosing an engine from the OBD trouble codes. It has been suggested to check my Crankshaft sensor, MAP, coil and EGR but these codes are not coming up. :icon_scratch: Misfire codes are not coming up.
Only CMP and O2. I changed the CMP and O2#1 and catylytic convertor..

Its a good suggestion to check EGR and Ill look into it bit Im a bit confused on why my scanner shows nothing for EGR. It also shows nothing for MAP, CKP, coil or misfire.

I ordered the exhaust manifold. I need to wait 3 working days. Im hoping they ship today. I am now studying the Fuel Trim percentages.
 

Attachments

  • OBD II trouble codes.jpg
    OBD II trouble codes.jpg
    67.7 KB · Views: 768
Re: Isuzu Mechanic Needed- problem still not solved

have you noticed a change in mileage ?
do you have an auto trans
 

Re: Isuzu Mechanic Needed- problem still not solved

Sniffer said:
have you noticed a change in mileage ?
do you have an auto trans
I have a manual transmission. I didnt check the gas mileage because I really dont care about it at this point. If you think this would help I could start checking it at next fill up.
 

Re: Isuzu Mechanic Needed- problem still not solved

as this point you probably won't see a difference, because you already have a problem
if seems to idle correctly, just lack of power trying to build speed, I would look at a restriction in either fuel, air,
exhaust. from everything you've said it's starving for something or possibly flooding.
if you have individual injectors, they may be squirting gas instead of spraying, which could be flooding the engine.
it's hard to diagnose a problem when you're not there
 

Re: Isuzu Mechanic Needed- problem still not solved

Just my 2 cents. If there is any cracks in any of the vacuum lines or clogged pcv valve, the computer will try to compensate with the fuel/air/timing, actually giving false trouble codes. Also, I had a chevy once that was dumping way too much fuel in the engine due to a temp sender telling the motor it was below zero. I also had an Alero that had misfires, lean on 1,3,and 5 and an evaporative leak, according to my scanner. The hose from the pcv to the intake had a crack in it. Sniffer is right, about being hard to diagnose when you aren't with the vehicle. Good luck with it.
 

Re: Isuzu Mechanic Needed- problem still not solved

misterbeee said:
Just my 2 cents. If there is any cracks in any of the vacuum lines or clogged pcv valve, the computer will try to compensate with the fuel/air/timing, actually giving false trouble codes. Also, I had a chevy once that was dumping way too much fuel in the engine due to a temp sender telling the motor it was below zero. I also had an Alero that had misfires, lean on 1,3,and 5 and an evaporative leak, according to my scanner. The hose from the pcv to the intake had a crack in it. Sniffer is right, about being hard to diagnose when you aren't with the vehicle. Good luck with it.
For some reason I searched and I read the manuals and there appears to be no PVC valve on this engine. All the vacuum hoses look good. Ill check again. I am beginning to think Im getting false trouble codes. I just checked and the same old original CMP code PO342 is back up even though I replaced the sensor. It came back up after I replaced the catylytic convertor. :icon_scratch: Thanks.
 

Re: Isuzu Mechanic Needed- problem still not solved

Sniffer said:
as this point you probably won't see a difference, because you already have a problem
if seems to idle correctly, just lack of power trying to build speed, I would look at a restriction in either fuel, air,
exhaust. from everything you've said it's starving for something or possibly flooding.
if you have individual injectors, they may be squirting gas instead of spraying, which could be flooding the engine.
it's hard to diagnose a problem when you're not there
Im also leaning toward a fuel injection problem now. I have 4 individual injectors in a bar. But at this point I may just wait on the manifold and fix that first. Its possible that a broken partition is blocking the exhaust or its messing up the O2 signal. I cant remove it yet because Im driving it. Im repairing my old Mazda for a back up.

Thanks I really appreciate it. I think Im going to get this solved.
 

Re: Isuzu Mechanic Needed- problem still not solved

you could have a plugged injector or possibly one or more that are squirting in gas.
take it out for a little drive and try to get it up to highway speed as fast as possible
mash it to the board and then pull over and check your tail pipe for a black almost powder
in the tailpipe. if it's black and chalky, that's a sign of unburned gas. if it's black and slippery
that's burned oil
 

Re: Isuzu Mechanic Needed- problem still not solved

Sniffer said:
you could have a plugged injector or possibly one or more that are squirting in gas.
take it out for a little drive and try to get it up to highway speed as fast as possible
mash it to the board and then pull over and check your tail pipe for a black almost powder
in the tailpipe. if it's black and chalky, that's a sign of unburned gas. if it's black and slippery
that's burned oil
When I mash it, it just goes blahhhh. But its black and chalky. There is a layer of black chalky dry soot in the tailpipe. I can scrap it out with a knife. Been that way since I bought the vehicle.. How do I know which injector is bad? Can I have them cleaned?
 

Attachments

  • MVC-035F.JPG
    MVC-035F.JPG
    102.2 KB · Views: 653
Re: Isuzu Mechanic Needed- problem still not solved

that's unburned gas, with it that bad you could probably see black smoke when you drive.
I'm not sure about cleaning them, however, there is a product called BG 44K fuel injection cleaner.
now most fuel injection cleaners are nothing but crap, but this one, is the only one I use.
I used it on my tahoe, which before got 10 mpg, after the BG 44K it climbed to 15 mpg
bad thing is you can't buy it in a auto parts store, you can only get it a repair places or I buy mine at a local salvage yard
this is one product that DOES work. give it a shot
 

Re: Isuzu Mechanic Needed- problem still not solved

Sniffer said:
that's unburned gas, with it that bad you could probably see black smoke when you drive.
I'm not sure about cleaning them, however, there is a product called BG 44K fuel injection cleaner.
now most fuel injection cleaners are nothing but crap, but this one, is the only one I use.
I used it on my tahoe, which before got 10 mpg, after the BG 44K it climbed to 15 mpg
bad thing is you can't buy it in a auto parts store, you can only get it a repair places or I buy mine at a local salvage yard
this is one product that DOES work. give it a shot
No smoke when I drive.
 

Re: Isuzu Mechanic Needed- problem still not solved

I suspect the rich condition could be caused (or compounded) by the cracked manifold, confusing the O2 sensors. But I see you are working to correct that.

I don't believe that crack would cause a blockage, but a blockage could exist for other reasons. If it's been running rich for a long time (sooty exhaust), the cat converter almost certainly would be clogged. The sudden increase in exhaust temp may have loosened enough soot to finally kill the cat. You don't have to guess about that, just use your vacuum gauge.

A clogged exhaust can cause high temps in the exhaust pipes. Running out of gas makes the mixture lean, which also raises exhaust temps. Both of these together may have cracked the manifold.

EGR- If it it's stuck open, you will see a problem. Stuck closed, I doubt you would see any change, since yours is a mechanical system.

Wish you luck, I know how aggravating these long term troubleshoots can be.
 

Top Member Reactions

Users who are viewing this thread

Back
Top