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"new" 87 Mj won't Start


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I just brought home a very clean 87 I4, 4 spd. Manual, 6' bed. It will turn over but won't catch and start. I changed the spark plugs, they were extremely fouled! I am thinking it might not be getting fuel, maybe the carburetor float is stuck or the filter is clogged or the fuel pump is bad. I need to put the battery back in and see if I hear the fuel pump. I'm also thinking it might not be getting spark. Maybe the spark plug wires are bad (need to be changed anyway) or the distributor? Hoping it isn't the (not sure of the acronym)ecu? Just wanna get it running so the wife will get off my behind about buying a piece of junk.

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Are you sure it is not TBI? For some reason I thought 86 was the last of the carbs.

 

If it is TBI, the first thing I would do is replace the CPS, crankshaft position sensor located on the edge of the bell housing behind/below the intake manifold.

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I have an 87 2.5 and it is aTBI

 

Before you start down the path of changing sensors lets just use the KISS method (Keep it simple stupid)

 

1) Take a plug out.....put the wire on and set it against the block so it grounds...have a buddy tun it over(don't be holding the plug).....is there spark.... you should be able to see it.....if yes replace the plug go to 2...if no post again

 

2) if you have spark and it still will not fire....take the intake hose off the TBI get a small bottle (Spray bottle works best) and toss some fuel down the TBI (just like a carb) keep your face away from it and try it again....if it still will not.....post again....

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I have an 87 2.5 and it is aTBI

 

Before you start down the path of changing sensors lets just use the KISS method (Keep it simple stupid)

 

1) Take a plug out.....put the wire on and set it against the block so it grounds...have a buddy tun it over(don't be holding the plug).....is there spark.... you should be able to see it.....if yes replace the plug go to 2...if no post again

 

2) if you have spark and it still will not fire....take the intake hose off the TBI get a small bottle (Spray bottle works best) and toss some fuel down the TBI (just like a carb) keep your face away from it and try it again....if it still will not.....post again....

86 was also TBI.

 

OP needs to be sure the vacuum hose to the MAP sensor on the firewall is in good ahape. If it isn't, the thing will run pig-rich and foul plugs badly.

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