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Tom, ASE Certified Technician
Category: Car
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Experience:  ASE Certified Master Technician
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Isuzu Rodeo: I have a 2004 Isuzu Rodeo 3.5 automatic 4x2, had

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I have a 2004 Isuzu Rodeo 3.5 automatic 4x2, had i since new...always serviced on time. I hit a rail in the road a fw months back and my insurance replaced the engine with a mechanic I knew, He put new timing belts, tensioners, etc in. I had a new starter about 9 months ago, a new battery abut a week ago and throttle body was removed and cleaned, and a new fuel pump, filter about three weeks ago. Now, mostly when it gets hot ( I live in TX, I am meaning 100+) It simple stalls out, usually when i let off the gas or am slowing for a light or turn. sometimes it starts right back up... sometimes you have to wait about 30 minutes or so to start again. On a basic meter, no codes show at all when event is occurring. Any Ideas?

Very common problem are failing fuel pumps. Was this checked ?
Customer: replied 4 years ago.
new fuel pump three weeks ago
Customer: replied 4 years ago.
pressure was checked as well, all good
Does it stat right back up after it stalls or do you need to wait awhile?Also was the new fuel pump programmed to the truck when it was installed ?
Customer: replied 4 years ago.
it sometimes does, sometimes doesn't... seems the hotter it is outside, the worst it is and the longer you have to wait, Pump was programmed i do believe. My hubby is a journeyman mechanic of 30+ years, but only experienced with Ford and diesels. can fix it if we can figure what it is. It shows no codes when hooked up to machine
Ok the common issue when this happens then is a shorting out crank sensor. All you need to do is when this stalls have the scanner hooked up in the data list screen and you can tell if crank sensor is producing a signal if not that's the issue . This is a very common problem on these trucks .
Customer: replied 4 years ago.
ok, if this isnt it, do I get charged or do we go forward from there?
If its is not the issue after clicking excellent service you can continue for no further charge and I will work with you until its fixed . Hoped this helped. Bonuses greatly appreciated. Please rate excellent service so I get credit for my help anything lower then ok service gives me negative feedback and I do not get compensated for my time thanks . If you need further assistance just let me know.
Customer: replied 4 years ago.
also. I can ask my hubby if he programmed the fuel pump...if i ask that, he will know what I mean? You diag this gremlin without just throwing money at it, and I will tip well. ")
Yes he will no. After fuel pump instalation on these trucks the fuel pump and sending unit need to be re calibrated . I'm sure it was . Again from your symptoms sounds like a shorted crank sensor. Hoped this helped. Please rate excellent service so I get credit for my help anything lower then ok service gives me negative feedback and I do not get compensated for my time thanks . If you need further assistance just let me know.
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Customer: replied 4 years ago.
Hi, the crank sensor is not the issue...what next?
Ok how was the crank sensor tested?
Customer: replied 4 years ago.
we had a spare in the garage, replaced it, still same issue
Ok it was the correct part for the vehicle has to be same part number.
Customer: replied 4 years ago.
yes, it came off the original engine that was referred to in original email, it was a fit
Since this happens after letting off the gas has the throttle position sensor been checked?
Customer: replied 4 years ago.
it was checked when the throttle body was off for cleaning, all good...I don't know how it was checked, i assume with a multimeter...but hubby said all was good
Customer: replied 4 years ago.
hubby just called, it was checked the same way, we have as spare parts engine, the entire throttle body was switched out, same issue
Ok all of these need to be reprogrammed they just can not be swapped.Also it can be a engine harness issue or even the electrical part of the ignition switch.
Customer: replied 4 years ago.
like I said, My hubby is a journeyman mechanic, has an Isuzu factory manual, I am sure he did what was needed. I am am starting to think it is a ECU issue?
Thats where Im leaning towards also but that would need to be programed with a professional scanner.
Customer: replied 4 years ago.
even if i had this one rebuilt? I have a friend who does that
No then there would be no programming needed if he could rebuild it.
Customer: replied 4 years ago.
i am sure he can check it as well, so I am going t have hubby pull it and i am off to the tech...will keep advised
Customer: replied 4 years ago.
well...ECM rebuilt , also installed fuel pressure sensor, same issue...on a scanner, when it stalls, the fuel pressure is over 85...runs fine between 50-80, then spikes to 88.3, flooding engine out...does this thing have a fuel regulator? if so, where is it? Can't seem to find it in schematics
Problem usually is the high pressure fuel sensor on the rail.Heres the diagram .
Customer: replied 4 years ago.
that was the fuel pressure sensor we just changed. Does this thing have a fuel regulator?
No just that sensor.
Customer: replied 4 years ago.
any other ideas...? this engine is almost rebuilt and still not running right
What was rebuilt on the engine so far ?
Customer: replied 4 years ago.
new fuel pump, new fuel pressure sensor , EMC ( rebuilt ) I was paraphrasing when i said " rebuilt "
Ok was there anything found malfunctioning in the ECM ?
Customer: replied 4 years ago.
As far as I know, they replaced a couple of capacitors
Ok a lot of times this rebuild does not work . I would make sure is good and if it's not then have the engine harness checked .
Customer: replied 4 years ago.

ok, will take it back and have it checked again

Ok keep me posted.