I’ve learned a lot on here already and I’ve seen many posts about issues similar to mine. Like many others, my Jeep only stumbles briefly when I first give it some gas and begin to move. Once through the low RPM’s under load from accelerating, it pulls strong as the revs increase. Seems to make most of its rated power when I need it. It’s just the off-idle nuisance that needs addressing. The Jeep has had this stumbling issue the entire time I’ve owned it, so nothing done to it has caused, made worse, or made better the stumbling. Now it’s time to address this last detail as far as driveability goes.
So, I thought that I’d post a few photos of what I’ve got under the hood today and what I may discover in resolving my own issue here. I’ve had this Jeep since 2019 and I have already seen to many issues since then. Here’s the maintenance history since 2019.
10/16/2019. 180,030 DIY: battery, wires, cap and rotor; New 5x 235R75/15 Master Craft tires, oil/filter service, 5 quarts QS 5W-30
10/16/2019. 180,031 new windshield.
10/19/2019. 180,033. DIY: Rampage center console, door skins, 992015 soft cab top w rear tonnea cover, door straps, headlight and fog light switches steering wheel and new horn contact, seats, seat belts, mirror, Weathertech mats, black interior dye over faded camel tan for dash and doors.
10/29/2019. 180,100 DIY: power steering pump, belts (17465 p/s and 15430 alt), hoses, clamps, antifreeze, PCV valve, valve cover gasket, Alpine CDE-HD149BT, Kicker 46CSC464 front, Focal 4” rear speakers, and 10” self-powered Kicker truck sub resting behind the seats
3/24/2020 180,400 DIY: CARID power steering gear w hoses and AutoZone p/s filter
3/25/2020. 180,420 DIY: alternator and new belt.
3/28/2020. 180,500 front brake service – new discs and calipers (AutoZone).
4/1/2020. 180,656 rear brake service – wheel cylinders (AutoZone), right side line (left was recent), brake fluid flush and refill all around, 4x Monroe shocks (Advance Auto).
12/24/2020. 181,009 Local trusted shop: New clutch – pressure plate, disc, pilot and throw-out bearing, fluid reservoir, machine flywheel, new rear main seal, drain and refill front and rear differentials with new gaskets, new water pump, thermostat and gasket, new rear brake drums and shoes, reweld bolts for cross member, new front u-joints.
4/1/2021. 181,372 Same trusted shop: New fuel tank and pump with sending unit, new gas cap.
Oil change every year while it was mainly parked and not driven very much. New battery and a right rear spring bushing in 2023.
7/28/2024. 185,427. DIY: Oil/filter service, 4.5 quarts QS 10W-30 High Mileage Standard Oil, new visors, gear shift knob, oil pressure gauge, aluminum valve cover w/ gasket, PCV valve and grommet.
So, you can see that I have fixed many issues over time. The engine itself has seemed ok and not in need of a rebuild or other major work. I feel better about everything else that has fluid coursing within it due to my having renewed the fluids found in every such system.
Now look at my photos. A prior owner removed the cat. They also crimped an air line that ran up to the bottom of the EGR valve. A Spectre air cleaner seems to have replaced the stock air box. Not shown, but a new exhaust system was also installed prior and it is just pipe from the stock cast iron manifold to a single muffler then on out back. I’ll comment below each photo as necessary.
Right side - love that aluminum valve cover - no more top oil leaks, at last! Notice how I had to graft in the 1990 PCV valve which draws in crankcase fumes through the existing CCV orifice that was left in the valve cover. My 1990 uses PCV but 1991 and up switched to a metering orifice (CCV) instead. I also removed the 1990 “can” at the rear of the valve cover that perhaps helped filter air being drawn into the engine by the PCV system.
Kept the 1991 clean air grommet and used its “fat” hose to slide a smaller diameter hose from stock system, did similar up front. Note the MAP sensor on firewall. See that thick hose just below and left, secured to the firewall and having some sort of valve or cap on it? I think it is part of the vacuum system for the 4WD.
Front side of throttle body. Some sort of throttle switch, engaged only at WOT? If there is something more of a TPS, where is it?
Detail view of the IAC, I believe? Do I remove this and clean it along with an orifice that it uses to allow air in as the PCM dictates?
Exhaust manifold has an O2 sensor with 3 wires. There’s an open fitting at the front of the down pipe maybe three inches below the flange where it meets the exhaust manifold. I think they welded this opening shut as no gas escapes it. Note the crimped air tube running down from the EGR valve that perhaps used to go to that pipe opening?
It sure was fun addressing the lack of power steering early on! Replaced just about everything involved including the steering box itself.
Another view of the exhaust area at the engine showing better the distance from the crimped air pipe to the opening on the down pipe.
Top view of the EGR valve and its relation to the throttle body. The EGR valve has a block-off hose, so no vacuum gets to it at present. Unless the EGR has another way to receive and admit exhaust gas into the throttle body I’m not sure what good it would do to restore vacuum to it - as long as there is no vacuum leak elsewhere! Initial checks find no vacuum leaks anywhere.
Here’s my factory emissions label - was glued in the proper location on a replacement hood! Original hood was crushed after a tree fell on the Jeep - per the prior owner!
So, I thought that I’d post a few photos of what I’ve got under the hood today and what I may discover in resolving my own issue here. I’ve had this Jeep since 2019 and I have already seen to many issues since then. Here’s the maintenance history since 2019.
10/16/2019. 180,030 DIY: battery, wires, cap and rotor; New 5x 235R75/15 Master Craft tires, oil/filter service, 5 quarts QS 5W-30
10/16/2019. 180,031 new windshield.
10/19/2019. 180,033. DIY: Rampage center console, door skins, 992015 soft cab top w rear tonnea cover, door straps, headlight and fog light switches steering wheel and new horn contact, seats, seat belts, mirror, Weathertech mats, black interior dye over faded camel tan for dash and doors.
10/29/2019. 180,100 DIY: power steering pump, belts (17465 p/s and 15430 alt), hoses, clamps, antifreeze, PCV valve, valve cover gasket, Alpine CDE-HD149BT, Kicker 46CSC464 front, Focal 4” rear speakers, and 10” self-powered Kicker truck sub resting behind the seats
3/24/2020 180,400 DIY: CARID power steering gear w hoses and AutoZone p/s filter
3/25/2020. 180,420 DIY: alternator and new belt.
3/28/2020. 180,500 front brake service – new discs and calipers (AutoZone).
4/1/2020. 180,656 rear brake service – wheel cylinders (AutoZone), right side line (left was recent), brake fluid flush and refill all around, 4x Monroe shocks (Advance Auto).
12/24/2020. 181,009 Local trusted shop: New clutch – pressure plate, disc, pilot and throw-out bearing, fluid reservoir, machine flywheel, new rear main seal, drain and refill front and rear differentials with new gaskets, new water pump, thermostat and gasket, new rear brake drums and shoes, reweld bolts for cross member, new front u-joints.
4/1/2021. 181,372 Same trusted shop: New fuel tank and pump with sending unit, new gas cap.
Oil change every year while it was mainly parked and not driven very much. New battery and a right rear spring bushing in 2023.
7/28/2024. 185,427. DIY: Oil/filter service, 4.5 quarts QS 10W-30 High Mileage Standard Oil, new visors, gear shift knob, oil pressure gauge, aluminum valve cover w/ gasket, PCV valve and grommet.
So, you can see that I have fixed many issues over time. The engine itself has seemed ok and not in need of a rebuild or other major work. I feel better about everything else that has fluid coursing within it due to my having renewed the fluids found in every such system.
Now look at my photos. A prior owner removed the cat. They also crimped an air line that ran up to the bottom of the EGR valve. A Spectre air cleaner seems to have replaced the stock air box. Not shown, but a new exhaust system was also installed prior and it is just pipe from the stock cast iron manifold to a single muffler then on out back. I’ll comment below each photo as necessary.
Right side - love that aluminum valve cover - no more top oil leaks, at last! Notice how I had to graft in the 1990 PCV valve which draws in crankcase fumes through the existing CCV orifice that was left in the valve cover. My 1990 uses PCV but 1991 and up switched to a metering orifice (CCV) instead. I also removed the 1990 “can” at the rear of the valve cover that perhaps helped filter air being drawn into the engine by the PCV system.
Kept the 1991 clean air grommet and used its “fat” hose to slide a smaller diameter hose from stock system, did similar up front. Note the MAP sensor on firewall. See that thick hose just below and left, secured to the firewall and having some sort of valve or cap on it? I think it is part of the vacuum system for the 4WD.
Front side of throttle body. Some sort of throttle switch, engaged only at WOT? If there is something more of a TPS, where is it?
Detail view of the IAC, I believe? Do I remove this and clean it along with an orifice that it uses to allow air in as the PCM dictates?
Exhaust manifold has an O2 sensor with 3 wires. There’s an open fitting at the front of the down pipe maybe three inches below the flange where it meets the exhaust manifold. I think they welded this opening shut as no gas escapes it. Note the crimped air tube running down from the EGR valve that perhaps used to go to that pipe opening?
It sure was fun addressing the lack of power steering early on! Replaced just about everything involved including the steering box itself.
Another view of the exhaust area at the engine showing better the distance from the crimped air pipe to the opening on the down pipe.
Top view of the EGR valve and its relation to the throttle body. The EGR valve has a block-off hose, so no vacuum gets to it at present. Unless the EGR has another way to receive and admit exhaust gas into the throttle body I’m not sure what good it would do to restore vacuum to it - as long as there is no vacuum leak elsewhere! Initial checks find no vacuum leaks anywhere.
Here’s my factory emissions label - was glued in the proper location on a replacement hood! Original hood was crushed after a tree fell on the Jeep - per the prior owner!
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