I had similar issues after I recently put in new ignition coil (found a Volvo OEM cross-reference in europe) and plugs, wires, cap and rotor, o2, coolant sensor and kicked it in the pants and told it to go plow some snow, but then the morning after our big storm I went to clean up and it took maybe 8 cranking sessions, some of 10-15 seconds to maybe warm up something and then thank god she ran and I could do the last job and some touch ups. But I knew something was off, especially when it dieseled on shut down (kept running after ignition off). this was helpful info www.howacarworks.com/ignition-system/curing-running-on I am guessing the main problem is quite likely in your cylinders. I idle a lot in the winter and coke builds up after many miles, and today I misted water through throttle body while running 2-3000 RPM, just pull off the final clamp and pull the intake off the TBI and use mist (mister/old windex bottle set to mist, not stream) be sure you are not pouring water in, or maybe mist seafoam, but I don't think there's a reason to use more than water (search hydrogen carbon cleaning, decoke). I pulled my O2 sensor (be sure to put anti-seize on it on re-install, and wear gloves, anti-seize will contribute to liver cancer, and other crap). I misted about 1.5 cups or 2, but probably half of it was blowing around and not entering, I did not see smoke, supposedly some people see a lot of smoke (maybe that was only with carburated engines?). I saw no smoke but it seemed to dramatically smooth out some things. I read about misting a whole lot (can't lose my work truck /snow plow to a destroyed engine or sensor), tried it, and it is no longer dieseling on shut down or at least it didn't after running hard with frequent runs at 3,4 and even close/at 5k RPM's to be sure to burn off water sitting anywhere bad, and, we may have cured the brief second or two of stutter at the start of 1st and 2nd gears when cold and accelerating (it may have been running at the low RPM's, did not seem to do it as much in 3rd-5th), and the fact it didn't start when it was 31F on Friday morning, and the dieseling at shut down and occasional rough idle. It did seem smoother, and definitely was smooth on shut down, unlike the last 4 years since I got it out of a barn and started using it to plow and tow some light stuff. I will test starting in a few days when it drops below 32 again. Great machine. Just sprayed with lanolin to prevent rust).
there was NO testing! climbing a highway hill is the most accurate way to determine power gain. the 2.5 will lose about 6 mph when going up a moderate highway hill. (manual with stock engine) nothing i have seen or read makes me believe that any real horse power gain is possible without major changes. cleaning the throttle body is a joke, only air passes through it! putting a restriction plate in sounds ridiculous. i just put in a forced air/cold air system in and will test the results tomorrow. the factory breather is a bad design but probably will perform just as well as the cold air system. i want to climb the hill with no speed loss!
Since I had now way to formally test, it becomes a seat of the pants kind of a thing. It did smooth my idle but very difficult to say it increased HP. I am going to try new injectors next to see if that has an impact.
i honestly have not found any way to get more power. the forced air- cold air intake resulted in "zero" hp gain which was disappointing. 2 days to install totally wasted. i do not like that the timing cannot be adjusted because in spite of the timing being accurately set as per manual the vacuum gauge says it needs more advancement.
@@heisenberg-c changing engines is the only logical option. changing gear ratios is very expensive and modifying the existing engine is very expensive. it is cheaper to buy a GM crate engine with adapters and end the problem.
@@jimlamb5508 I imagined that. When I bought mine Feb 2018, prev owner had it on 33's but he only changed gears on rear axle. Then I had to do it to the front if I wanted to use 4X4 and of course that was all about when I even thought in buying a JEEP. and yeah, it was expensive, almost $1K. Do you have more info or a website about the type of engine and adapters ans etc. At least to look it up. I've been adding and fixing stuff on my own helped by youtube, but I'm not a mechanic or knowledgeable in this area.
