tmaxx411 Posted January 18, 2019 Share Posted January 18, 2019 I've got an 86 2.5l, that was originally 2wd with a 904 trans. It's been converted to an ax5 4wd. Once the transmission was finished, I started on the motor. Previously the truck had an exhaust leak, and a fairly high idle.(1400 rpm) I pulled the intake/exhaust off, and discovered the manifold was cracked in 2. I ordered a new replacement manifold and put it all back together. At first it wouldn't start. Then it would only start if I sprayed starter fluid into the intake, and it idled around 3000 rpm. I capped all the vacuum lines on the vacuum harness and it with difficulty it started and idled at 1500 rpm. Then I removed the harness all together and called the lines at the ports, and it started normally and idled at 1000 rpm with what sounded like a misfire. I hooked the map sensor back up with brand new vacuum line and it's back to 1500 rpm and hard to start. It doesn't sound like it has a misfire though.. Where do I start? Tldr: replaced exhaust manifold and gasket, found a bunch of vac leaks, capped everything. Truck starts and runs with a misfire. If I reconnect vacuum to the map sensor, it idles at 1500 rpm and is hard to start New: Exhaust (manifold back) Exhaust manifold gasket Iac Waterpump Thermostat Cap Wires Plugs Aluminum valve cover (91+) Link to comment Share on other sites More sharing options...
tmaxx411 Posted January 20, 2019 Author Share Posted January 20, 2019 Bit of an update, I discovered that even though the gasket and such are brand new, there is a pretty bad vacuum leak from the intake flange. Any tips/tricks to getting it to seal? Going to go grab new bolts tomorrow or tues Link to comment Share on other sites More sharing options...
Pete M Posted January 21, 2019 Share Posted January 21, 2019 is it a failure of the gasket? bolt backing out? Link to comment Share on other sites More sharing options...
Green Mesa XJ Posted January 21, 2019 Share Posted January 21, 2019 When I saw this it was a warped intake. Had to be machines flat again. But this was a very old car long gone. I haven’t had trouble with Jeep intakes usually the gasket is thick enough to compensate for any slight warping. Sent from my iPhone using Tapatalk Pro Link to comment Share on other sites More sharing options...
Jeep Driver Posted January 21, 2019 Share Posted January 21, 2019 Something tells me the OP is not using the correct washers. Link to comment Share on other sites More sharing options...
mjeff87 Posted January 21, 2019 Share Posted January 21, 2019 If I remember correctly, there's a couple dowel pins that the intake manifold aligns with. Make sure it's seated properly on them. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now