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the Tahoe cranks the system holds fuel pressure we replaced the 02 sensors all 4 of em the spider injector system with regulator the computer still says the engine is running rich on both banks I have a flashing engine light but at times the engine light will go out it comes on for random cylinder misfire and rich the engine will surge really bad it will also shudder sputter hesitate has loss of power and at times when cruising and breaking will have a sudden rush of power and will accelerate without mashing the gas when it does this the cylinder misfire will go away and it will even sometimes run right long enough to turn out the check engine light but it will still surge at idol the rpm will drop and rise about 50 rpm it will also stall out at times when I put it into revers drive or park we replaced the maf sensor fuel injectors with regulator fuel filter spark plugs wires cap and rotor also had the intake manifold gaskets replaced and some vacuum hoses the temp sensors and egr have all been checked for operation it has a bunch of fuel pump related symptoms but the computer says its running rich but I can feel when it has a sudden rush of power the misfire goes away and the engine will smooth out and run better I let it sit for 2 weeks without running I put the key and cranked it without priming the engine and it started right away its holding fuel pressure in the lines for weeks without running and after that it ran great nice and smooth but the exhaust stunk bad and it ran okay till it heated up sometimes when I pull up in the driveway put it into park the rpm will drop to about 400 and it will act as if its starving for fuel but according to the computer its running rich also the tps has been replaced also the iac also sometimes when the ac compressor kicks out it will almost stall the engine but it will run smooth out of gear when it hits drive and the ac kicks in its under load it will run like crap ive taken the belt off all the pulleys are lose and free the belt and idler and tensioner are all new less then 10,000 miles old as with the full tune up we have been trying to fix this issue for about 6,000 miles this is why I have been planning to tak it to scotty unless maybe you can help me we are about to try a new fuel pump on it please help.
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Do you only have a code for the vehicle running rich on both banks? I’ve seen symptoms like this when a vehicle enters limp mode, but I’ve only heard of vehicles entering limp mode there are problems with shift solenoids in the transmission.
I had a problem very similar to what you mentioned on a 98 ford expedition. It would start and idle very poorly, but once under load it would fall on its face. The power delivery was very sporadic. At first I thought it was the fuel pump or a spark issue, but after some further checking, it turned out that the computer was just limiting the motor’s torque output. (that’s at least what the service manual said) I’m not sure if both that vehicle and the one you mentioned in this post work on the same principle, but I would check to make sure all your fuses are good.
the transmission has less then 60,000 on it shifts smooth the engine has 230,000 I can get it up to 75 easy on freeways this issue has started oh shortly after march it has a code for random misfire so we thought the injectors with the pressure regulator so we had that famed spider injector replaced no change we also replaced the iac and tps all the spark plugs and wires also the whole rotor assembly has been changed no change the computer has been tested and is working correctly when I go above 45-50 mph the engine light will start flashing but if I lets say should hit a bump and ill get a rush of power just like as if fule pump cant keep up the engine will smooth out and run better and the engine light will stop flashing the engine at times acts like its not getting fuel it runs really rough and vibrates all really hard the car will shake but when it starts trying to take off on its own and has that sudden rush of power all the symptoms seem to go away all the fuses and relays test fine the timing has been checked as well timing system is fine and is correct like I said the issue started about march 6,000 miles we did a full tune up hoping to fix this issue no luck the spark plugs looked like a rich engine there is no oil in the coolant or oil being burned the head gasket is good the intake manifold is new it was completely rebuilt few years ago heres a video I took after I did the tune up which made it rune great for only 1,000 miles then back in the same bout.
this is it no with the engine light on its missing and surging but hard to tell with the poor video quality
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