92 SC400 Did timing/water pump/ignition system upgrades engine cranks but wont start up

[TheGreatSamdini]

Just finished up the timing job on my 92 sc400 and put it back together last night and tried to turn it on for the first time in a month and it just will not start. As I crank it longer, I notice a rather loud spark noise and one of the last times I tried to start it I heard that same noise except REALLY loud and then ran up to the front to see smoke and a burning-like smell coming from the passenger side, good to note I had both valve covers off..I just installed new NGK G Power plugs and NGK blue wires...the caps & rotors were replaced before with the Bosch ones by a previous owner and they looked fine to me so what could cause all of that?? Maybe I did wrong by not replacing the rotors and caps anyways?

 

[gloverman]

If it ran before you worked on it and now it doesn't run then chances are you have done something wrong. Common mistakes are broken connectors beside #1 injector, loom breaking to crankshaft sensor, failing to fit crank trigger wheel, fitting leads in incorrect firing order, incorrect fitment of rotors. Time to check over your work and do some diagnosis.

 

[TheGreatSamdini]

Its funny cause on lunch break today at work I retraced my steps and realize that I installed the rotors at completely opposite directions..did em right and the engine seemed a lot more willing to come to life than before but not quite there, so I reinstalled the intake/maf and it's SO close to starting but it just can't seem to. The only things not connected are the coolant temp sensor(broke the old connector and havent soddered the new one to the harness), the hose connecting to the thermostat, and that one sensor right on the 2nd ignition coil bracket(No idea what it is but the connector broke off the wiring LOL)

 

[gloverman]

I did a video on youtube of an engine running on two cylinders. In that it shows they are often reluctant to start without EFI temp sensor.

 

[gloverman]

that second sensor on the coil is most likely not a sensor at all but a noise suppressor.

 

[TheGreatSamdini]

Mr. CarTune! I've watched a couple of your videos already and I love them! I connected the temp sensor and realized that injector #1 was also disconnected, so I fixed that and now the car starts up but dies after a few seconds and sounds rough. White smoke steams out from the exhaust as well as the engine bay too.

 

[gloverman]

Doesnt sound good. Maybe look over what you have done.

 

[TheGreatSamdini]

Took my time as I had life issues to deal with, but I've made some rather interesting discoveries with my sc. I rechecked the timing and the cam pulleys and balancer were all still lined up, and the timing belt is fine. Checked fuel by disconnecting the lower hose on the driver side of engine bay and it was a very consistent flow. Now today, I took off the serpentine belt and reinstalled it to see if anything changes and sure enough, I forgot to tighten down the bolts for the A/C compressor haha. Fixed that, reinstalled the serp. belt, started the car and NOW the engine stays running instead of dying immediately after startup BUT it still sounds like it runs on several cylinders and still smokes EXCEPT NOW it doesnt smoke much from the tailpipes and the smoke up front is only coming from the rear of the engine instead of from the rear+passenger side. At the same time there is a weird noise that sounds like a dang washing machine spinning or something. I could tell that the engine was trying to get up to normal cold start idle, but it just cant quite seem to get there. All cylinders have about 190 compression. After having my brother start the car while I watch the engine bay, I discovered that the belt tensioner wobbles up and down. Im pretty sure the bolt loosened in the process, so if I tighten that down perhaps it'll stop wobbling, although I'm still not sure if that will solve the overall problems...will it???

 

[gloverman]

Good Luck with your diagnoses. Just use normal techniques to check it all over. Find what cylinders arent firing. Work out which components are at fault.

 

[TheGreatSamdini]

Hey buddy, I realized that I didnt tighten the crank bolt to spec(rookie mistake!), of course causing the motor to run rough. It still smokes on startup though. From my extensive research, It seems that all signs point to the valve stem seals, as after I did the timing job I acquired the 'notorious' smoke on startup. Before the job, this did not occur. I remember when I was turning the crank I went backwards and heard a thud followed by two, more rapid thuds from the passenger side. Ever since then, smoke would come out of the passenger head upon startup as well as the back of the engine and exhaust. Checked underneath the car and found liquid residue, I thought it was fuel because of how thin it was but people say it would be oil, which would explain why the smoke was so much, although I did not notice any loss of oil from the dipstick. When I removed the fresh NGK spark plugs, however, I did notice that 2 of the 4 plugs on the passenger side were fouled and had darkened. I already have fresh valve stem seals and I am prepared to replace the original ones if necessary, but I wanted to run all of this by you beforehand, Mr. CarTune. This is my very first date with timing stuff haha, and as overwhelming as this has become, I am eager to learn from all of this and become better as a young mechanic!

 

[gloverman]

I would be doing a compression test at this point.

 

[TheGreatSamdini]

I did check compression once after the initial startup and all cylinders were consistent 185-190, so I doubt it would be the piston rings