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General Forums => The Mess Hall => Topic started by: macfeargus on September 06, 2015, 10:29:17 PM

Title: 1990 2.5l TBI Rebuilt head now it wont start help!
Post by: macfeargus on September 06, 2015, 10:29:17 PM
Pulled apart the wifes engine did a valve job on it everything by the book put it back together replaced over half of the vacuum lines that were rotted out and now we cant get it to start, not even spit and sputter. It is getting fuel and spark timing is right just wont fire any help will be greatly appreciated.
Title: Re: 1990 2.5l TBI Rebuilt head now it wont start help!
Post by: Jeffy on September 06, 2015, 11:03:24 PM
You have the distributor timed properly?
Title: Re: 1990 2.5l TBI Rebuilt head now it wont start help!
Post by: macfeargus on September 07, 2015, 04:59:45 PM
didnt touch the distributor put i did check it and it is correct. i checked the compression and it was low so i took it  back apart and did a ring job put it back together acted like it was going to start and then nothing back to crank but now start. it is getting plenty of fuel you can see it in the bottom of the intake manifold.
Title: Re: 1990 2.5l TBI Rebuilt head now it wont start help!
Post by: Jeffy on September 07, 2015, 07:55:51 PM
Sounds like a sensor isn't hooked up or isn't working properly.
Title: Re: 1990 2.5l TBI Rebuilt head now it wont start help!
Post by: 95 Lowbuck on September 08, 2015, 05:45:55 AM
If you have good compression, a good spark, and fuel,
I would go back to the timing issue and double check your spark plug wires.
You should at least get a pop out of it.
Title: Re: 1990 2.5l TBI Rebuilt head now it wont start help!
Post by: macfeargus on September 08, 2015, 11:08:24 AM
If keep the pedal all the way down it almost sounds like it is going to start
Title: Re: 1990 2.5l TBI Rebuilt head now it wont start help!
Post by: kashola on September 08, 2015, 03:51:20 PM
Did you check compression after the ring job? 
Title: Re: 1990 2.5l TBI Rebuilt head now it wont start help!
Post by: macfeargus on September 08, 2015, 05:06:08 PM
9 to 9.5
Title: Re: 1990 2.5l TBI Rebuilt head now it wont start help!
Post by: chardrc on September 08, 2015, 05:34:58 PM
Is the crank position sensor plugged in (timing)? How about the vacuum line and electrical connector to the map sensor? As others said sounds like a timing issue. The jeep should cut all fuel if you floor it while using the starter (that is supposed to tell the ecu that the engine is flooded).
Title: Re: 1990 2.5l TBI Rebuilt head now it wont start help!
Post by: macfeargus on September 08, 2015, 05:47:03 PM
i tested the The crank position sensor it ohm at 225 which from what i read is about right. the timing is on I have went threw all the vac lines everything is good I dont know about the MAP sensor.  :brick:
Title: Re: 1990 2.5l TBI Rebuilt head now it wont start help!
Post by: sharpxmen on September 30, 2015, 10:38:10 AM
in case you're still not able to start it, in addition to what's been said already (sensor wires/connectors, etc):
 - check the spark at the spark plug wire (if instead you checked at the coil).
 - check the fuel pressure while cranking.
 - take a spark plug out, is it wet with gasoline?
 - keep one of the spark plug wires out and connected to a spark plug while cranking, make sure the spark is present during the whole time you crank the engine and not just at the beginning, if there's an error the PCM will cut out the spark and the fuel pump after a few cranks.
 - take the valve cover off and put cyl 1 in compression at tdc with both valves closed and at 0 deg mark on the harmonic balancer (with cyl 4 valves in balance as in exhaust closing and intake just starting to open) and verify that the rotor is pointing to cyl 1 wire. Check the firing order from there and make sure is not messed up.
 - this is an extremely unlikely scenario but will mention it anyway: have you checked the preload on the lifters, if you decked the head how much did you take off

hope this helps