Isuzu Repair: 2004 Isuzu Rodeo P1239 Code, fuel delivery system, isuzu rodeo

Question
I have seen a recent question regarding the trouble code P1239. Although I do  not have an answer for it have have been through a lot of diagnosing which has yielded no answers to what the real problem is. I am having problems with the check engine light coming on intermittently. When I purchased the vehicle 6+ months ago after 2 days the light came on. I took the vehicle to my mechanic who did a thorough inspections of the ignition system, the fuel delivery system as well as all electronics and said that everything looked great. He cleared the code and for the next 6 months I never saw that light again...Until today. I returned to autozone and the gave me a print out of the possible causes as follows:
High fuel pressure system fault - Pressure high or low
1. check fuel quantity and quality
2. check for restriction
3. Open or short circuit condition
4. check repair resource for diagnostic procedure
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So, I am currently back where I started. A check engine light that's on and no idea why. The deal said the fuel pump needed to be replaced, only $1100.00 to do that. My mechanic said all fuel pressure was good. In fact I think he said something like it was 41 lbs. which is right where factory specs state. Not too sure on the amount though as it was over 6 months ago. Anyway, has there been any progress on this issue?

Answer
Well James put your wallet away and by a new pump on ebay for a new fuel pump. I bet you your fuel pump sending unit is to blame. I have seen this before and the fuel level sending unit goes bad- causes the computer to think there's no gas in the tank and puts a CEL as well. I would be surprised if that wasn't it. Does your fuel guage bounce around at all or act strange sometimes??? fuel level sending unit is about 50 to 60.00 dollars on ebay, comes with all the parts you need.