Help: #$%@& Jeep Engine!!! - Pirate4x4.Com : 4x4 and Off-Road Forum

justasammy · 04-26-2006, 05:43 AM

I have a '97 Jeep Wrangler with the 2.5l 4 cylinder engine and the AX5 manual transmission. Recently it passed a 100k on mileage so I made a few engine upgrades; I installed E3 spark plugs, Accell 8.8 plug wires, Accell coil, Pacesetter header and a 2.25" exhaust with a turbo muffler, a throttle body spacer, and a Rock-It Parts Max Flow intake system. I also replaced the O2 sensors when I did this work. Normally, it starts and idles just fine; the problem is when I drive down the road. The Jeep will bog down and surge or just die. Sometimes when I have to come to a stop it will drop below its normal idle RPM and die. Anyone have any ideas? I have thought about the Turbo City adjustable MAP sensor but have not heard any reviews as to whether or not it corrected anyone's problems.

fullygruntled · 04-26-2006, 05:52 AM

I would suspect one of the hundred odd aftermarket parts you just put on it.

Start with the TB spacer. Make sure it's sealed, or just try removing it.

justasammy · 04-26-2006, 06:02 AM

Actually, the TBI spacer has been on there for a full two years prior to the other upgrades without any problems; I mainly just mentioned it so everyone would know it was there. Another item is that the "Check Engine" light never comes on when it starts to surge.

jaybirdd · 04-26-2006, 06:16 AM

Fuel filter? If ya cant remember when ya did it last, it needs done!

justasammy · 04-26-2006, 06:18 AM

I replaced both the fuel tank and pump/regulator/filter (on TJs its all one unit in the tank) about a year and a half ago.

Rattlecan · 04-26-2006, 06:33 AM

Check the idle control on the rear of the throttle body. Sounds like you may have buggered it when you installed the air intake.

justasammy · 04-26-2006, 06:48 AM

That will give me something to check out; but would it affect it running down the road @ 45mph and 2500rpm?

Rattlecan · 04-26-2006, 06:56 AM

It might.

When you replaced the o2s did you go to the local parts store - or did you buy from the dealer?

90yj · 04-26-2006, 07:40 AM

i would double check all of your spark plug wires and your coil. Make sure your coil has the wires with nice clean contact points,accell coils can be kinda finicky from what ive learned. Also make sure the order of your plug wires is correct. Make sure your spark plug gap is correct also,you may have bumped it putting it in or something like that

justasammy · 04-26-2006, 08:02 AM

The O2 sensors are Bosch direct replacement (no splicing) units; The spark plug gap is set from the factory since the spark plug has a fixed crown instead of a single electrode; it idles smooth at first startup so I know the spark plug order is correct. I also pulled the coil connections yesterday to make sure everything was clean and snug. And I replaced the cap and rotor just to be sure that they were good; even though there were no signs of heat tracking on the old cap and the rotors contacts looked clean.

justasammy · 04-27-2006, 05:53 AM

I may have located the problem; Pacesetter uses a "ball & socket" style coupler flange for the header into the exhaust pipe. When I installed the exhaust, I had it lined up vertically so it had plenty of surface area to mate. I took it to an exhaust shop to have a new turbo muffler welded in, and they used a small-body turbo muffler so they had to tweak the exhaust a little. In doing so; the flange doesn't line up like I had it; so any time you hit a bump it produces a gap which makes the engine run way too lean; therefore it dies. Does this make sense to anyone? I will try to repair the exhaust or just reinstall a stock manifold so everything is done correctly.

04-26-2006, 05:43 AM	#1 (permalink)
justasammy Registered User Join Date: May 2003 Member # 19567 Location: Lubbock Posts: 26	Help: #$%@& Jeep Engine!!! I have a '97 Jeep Wrangler with the 2.5l 4 cylinder engine and the AX5 manual transmission. Recently it passed a 100k on mileage so I made a few engine upgrades; I installed E3 spark plugs, Accell 8.8 plug wires, Accell coil, Pacesetter header and a 2.25" exhaust with a turbo muffler, a throttle body spacer, and a Rock-It Parts Max Flow intake system. I also replaced the O2 sensors when I did this work. Normally, it starts and idles just fine; the problem is when I drive down the road. The Jeep will bog down and surge or just die. Sometimes when I have to come to a stop it will drop below its normal idle RPM and die. Anyone have any ideas? I have thought about the Turbo City adjustable MAP sensor but have not heard any reviews as to whether or not it corrected anyone's problems.

04-26-2006, 05:52 AM	#2 (permalink)
fullygruntled Registered User Join Date: Jan 2002 Member # 9614 Location: Charlottesville, VA Posts: 1,008	I would suspect one of the hundred odd aftermarket parts you just put on it. Start with the TB spacer. Make sure it's sealed, or just try removing it. __________________ Choose Life. Preferably Cinnamon. [url]http://McBob.TV[/url]

04-26-2006, 06:16 AM	#4 (permalink)
jaybirdd Registered User Join Date: Nov 2005 Member # 57933 Location: western PA Posts: 66	Fuel filter? If ya cant remember when ya did it last, it needs done! __________________ I'm not very bright, big words confuse me, and I have the attention span of a rodent.

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04-26-2006, 06:02 AM	#3 (permalink)
justasammy Registered User Join Date: May 2003 Member # 19567 Location: Lubbock Posts: 26	Actually, the TBI spacer has been on there for a full two years prior to the other upgrades without any problems; I mainly just mentioned it so everyone would know it was there. Another item is that the "Check Engine" light never comes on when it starts to surge.

04-26-2006, 06:18 AM	#5 (permalink)
justasammy Registered User Join Date: May 2003 Member # 19567 Location: Lubbock Posts: 26	I replaced both the fuel tank and pump/regulator/filter (on TJs its all one unit in the tank) about a year and a half ago.

04-26-2006, 06:33 AM	#6 (permalink)
Rattlecan Rock God Join Date: Jul 2005 Member # 50639 Posts: 1,216	Check the idle control on the rear of the throttle body. Sounds like you may have buggered it when you installed the air intake.

04-26-2006, 06:48 AM	#7 (permalink)
justasammy Registered User Join Date: May 2003 Member # 19567 Location: Lubbock Posts: 26	That will give me something to check out; but would it affect it running down the road @ 45mph and 2500rpm?

04-26-2006, 06:56 AM	#8 (permalink)
Rattlecan Rock God Join Date: Jul 2005 Member # 50639 Posts: 1,216	It might. When you replaced the o2s did you go to the local parts store - or did you buy from the dealer?

04-26-2006, 07:40 AM	#9 (permalink)
90yj Registered User Join Date: Feb 2006 Member # 67951 Posts: 51	i would double check all of your spark plug wires and your coil. Make sure your coil has the wires with nice clean contact points,accell coils can be kinda finicky from what ive learned. Also make sure the order of your plug wires is correct. Make sure your spark plug gap is correct also,you may have bumped it putting it in or something like that

04-26-2006, 08:02 AM	#10 (permalink)
justasammy Registered User Join Date: May 2003 Member # 19567 Location: Lubbock Posts: 26	The O2 sensors are Bosch direct replacement (no splicing) units; The spark plug gap is set from the factory since the spark plug has a fixed crown instead of a single electrode; it idles smooth at first startup so I know the spark plug order is correct. I also pulled the coil connections yesterday to make sure everything was clean and snug. And I replaced the cap and rotor just to be sure that they were good; even though there were no signs of heat tracking on the old cap and the rotors contacts looked clean.

04-27-2006, 05:53 AM	#11 (permalink)
justasammy Registered User Join Date: May 2003 Member # 19567 Location: Lubbock Posts: 26	I may have located the problem; Pacesetter uses a "ball & socket" style coupler flange for the header into the exhaust pipe. When I installed the exhaust, I had it lined up vertically so it had plenty of surface area to mate. I took it to an exhaust shop to have a new turbo muffler welded in, and they used a small-body turbo muffler so they had to tweak the exhaust a little. In doing so; the flange doesn't line up like I had it; so any time you hit a bump it produces a gap which makes the engine run way too lean; therefore it dies. Does this make sense to anyone? I will try to repair the exhaust or just reinstall a stock manifold so everything is done correctly.