Jeep Wont start

[daking]

I have an '87 Jeep with a 4.0 I6 engine.

 

I just had the clutch replaced. They also replaced the crank sensor.

 

We put gas in after we picked it up from transmission shop. Jeep Drove ok. It had a rough idle. The engine would stall sometimes when driving during the day. I strong "burning" smell, plastic or electric,, not sure.

 

well, later that day it would not start. It cranks, but will not start.

 

Checked for spark at coil, it was weak, so I replaced the coil.

Checked for fuel, the shader valve on the fuel rail had pressure.

Checked electrical connections.

 

I found a peace of vacuum hose just laying on the engine, I figured out later it goes to the MAP sensor on the firewall. But the solid vacuum hose was broken, and I have no idea where it supposed to go. Someone told me it won't start if there is no vacuum on the MAP sensor..

 

any ideas on what to look for?

 

Thanks

[MJRemi]

viewtopic.php?f=2&t=22342&p=230337&hilit=vacuum+line+diagram#p230337

[daking]

Thanks, do you think it won't start if there is no vacuum on the MAP sensor?

 

It shows the line going to the TB, but I can't see an open vacuum hole.. anyone got a real picture of it connected?

 

thanks

[MJRemi]

Image Not Found

 

Below the air intake on the inside of the throttle body, you can see an oval rubber grommet where the MAP line attaches to the side of the TB. I believe the detached vacuum line would just make the engine run like crap, not prevent it from starting. I am not as knowledgeable as others on here so if I get corrected I will not suck my thumb.

[daking]

Thanks, I'll connect it tomorrow.

 

It still won't start. I put on new plugs, wires, cap, coil, and rotor.

 

It cranks but won't fire up. What else could cause this?

 

thanks

[MJRemi]

Check your fuel system components. Perhaps the fuel relay or the pump/sending unit. It's hard to diagnose and I'm no expert so hopefully another member can chime in.

[daking]

Thanks, there is fuel pressure in the fuel rail. I'll hook up a gauge to test the PSI. Manual says ~39psi or so, does not feel like that much PSI when I release the valve..

 

speaking of relays, does anyone know what the 4 relays on the passenger side, near the coil are for?

 

thanks

[HOrnbrod]

Check the ignition starter switch, left side of the lower steering column. Press the switch by hand tight to the column and try to start. If not, remove and look for burnt contacts.

[daking]

Check the ignition starter switch, left side of the lower steering column. Press the switch by hand tight to the column and try to start. If not, remove and look for burnt contacts.

 

 

Thanks, I'll check that today

[daking]

humm, still won't start. just cranks over and over..

 

Has Spark

Has Fuel

Has Voltage

Has air

 

any ideas?

[vaquaro]

You mention a wire burning smell , might be the wire going down to sensor on the bellhousing ( crank / engine speed sensor ) . I have encountered this problem in the past where the wire lays against the exhaust ( hence the burning smell ) and cured it by installing a Nomex sleeve to protect the replacement unit wires from damage . :thumbsup: