J30 shaking and wasting gas with a bold smoke

[expertie]

Hello,My 94 J30 started this weird problem. It will suddenly start shaking and making a bold smoke coming out of the exhausts. The smell is like raw gas and the J30 makes less than 5mpg. But it goes away after you cool down the car for a few hours. But you never know when it will happen again. This is the 3 times it happened in the last 3 weeks:(Please advice

[elwesso]

First thign id check is your injectors..... Check the resistance (should be abel to do it the same way as the Qs)...

If any of the injectors arent in spec, then there is your problem, especially if one or 2 is a closed or open circuit.

[expertie]

elwessso,i went to a mechanic. he read the ecu codes. the crankshaft and knock sensor errors came up. he said knock sensor is probably the problem. he also suggested me to use fuel injector cleaner. if i wanted to fix those sonsor, it will cost a lot of bucks.a friend of mine says this is about the dustributor (oil leak into the distributor, camshaft etc...)i dont know how to check the fuel injectors by the waydo u still think its the fuel injectors?

[Jesda]

Are the injector harnesses on the J accessible without removing the plenum? You need to take a multimeter and measure the resistance in ohms.

So, to clarify, the only happens when the engine is warmed up? Does it happen after a while on the highway, or only in city driving? Does it happen only when you restart it after running it and warming it up?

[expertie]

First it happened when the car was in idle (warm). Then it happened in the morning when the car was cold. The last time it happened was when I was driving in the city. The engine suddenly lost power and u had to push the gas very hard so that the card would move. The engine shakes and makes a noise when u press the gas, as if it doesnt wanna run.

[Aussie Q45a]

First it happened when the car was in idle (warm). Then it happened in the morning when the car was cold. The last time it happened was when I was driving in the city. The engine suddenly lost power and u had to push the gas very hard so that the card would move. The engine shakes and makes a noise when u press the gas, as if it doesnt wanna run.

Have you checked your transmission codes?

[kieranmcmullen]

not sure if this helps? I have a 97 j30 and almost ayear agomine did the same thing. really bad idle, smoked bad andsmell of raw gas. I took it to two shops and nothing they could find. they said a code for multiple misfires, my car had an engine light on already. they said that if fixed the air control motor valve and my problom codes would bemore acurite for witch cylinders were misfiring. i ran out of money but the car fixed itself.now today almost a year later it did it agian tonight.I was thinking and am again thinking bad gas. hope this might inderectly help with what it's not. I'm going to put gas dryer and some 92 octane and see if that helps, if not then try some top end cleaner/injector cleaner.only preimium gas right? if you find somthing out let me know please at " [email protected] " thanks

[Gerardjg]

Are the injector harnesses on the J accessible without removing the plenum?

There is a connector on the top of the intake just behind the fuel damper (back passenger side) where you can ohm all the injectors from.

[Q45tech]

MAF connector or MAF itself [even though no code]?