Just bought a 94corolla that had a blown headgasket. Sent out the head and had the machine shop do there thing. Resurface head,clean,pressure test. I installed the head when I got it back with of course new seals. And now the dam thing won't start. It has spark and fuel. Compression is testing out about 150-160. When I crank it for longer then 8 secs it sounds like it wants to start but still nothing. I've checked timing four times and its perfect. Only thing I could think of is that valves. When I sent the head out the guy called me and said "this thing needs a valve job bad". I told him do what he has to do. But the next day he called again and told me I could get away with a valve adjustment. I said great. Now is it possible the valves were never adjusted or maybe he did it wrong? I really don't want to pull the head again but I need to figure this thing out. Registration expired and I need to get it smogged. Help fellas!
94 corolla no start issue
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Did you check both cam timing and spark timing? Put the number one cylinder to TDC compression and see if the distributor rotor is pointing to the number 1 cylinder as referenced in a repair manual with how the distributor should be lined up. ie, when number 1 cylinder is at TDC compression, is the rotor pointing at the contact on the distributor which has the spark plug wire going to the number one cylinder?
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If the valves were a problem it would show up in a compression test. You wouldn't be seeing consistent compression on all cylinders. This sure smells like valve timing or ignition timing. Is this a distributor system?
Originally Posted By: tinmanSC
If the valves were a problem it would show up in a compression test. You wouldn't be seeing consistent compression on all cylinders. This sure smells like valve timing or ignition timing. Is this a distributor system?
I just called the mechanic that's helping me do the work. And he's the one that checked compression. To clarify he said when he first put on the head and cranked it with a compression tester on. It was about 60-90. Then he put some oil in it and it was about 150-160. After that we rechecked all timing,distributor components,fuel. and compression tested it again and itwas 70-90. He basically told me he thinks its a valve issue due to everything checking out good. If it was rings the thing would still start just run like [censored]. Right?
If the valves were a problem it would show up in a compression test. You wouldn't be seeing consistent compression on all cylinders. This sure smells like valve timing or ignition timing. Is this a distributor system?
I just called the mechanic that's helping me do the work. And he's the one that checked compression. To clarify he said when he first put on the head and cranked it with a compression tester on. It was about 60-90. Then he put some oil in it and it was about 150-160. After that we rechecked all timing,distributor components,fuel. and compression tested it again and itwas 70-90. He basically told me he thinks its a valve issue due to everything checking out good. If it was rings the thing would still start just run like [censored]. Right?
I never worked on one of those, but most engines have marks on the gears that you use to get the cam timing right. Your cam(s) can be 180 out of sync if you took the the cam system apart and put it back together without 1) Paying special attention to positions, or 2) use marks on gears to keep things timed properly.
I was under the impression a wet vs dry compression test verifies ring seal.
Originally Posted By: JimPghPA
I never worked on one of those, but most engines have marks on the gears that you use to get the cam timing right. Your cam(s) can be 180 out of sync if you took the the cam system apart and put it back together without 1) Paying special attention to positions, or 2) use marks on gears to keep things timed properly.
I agree. Same with the distributor. You can check it a thousands times and think it's right, but if it's wrong, no start. Especially if the camshafts themselves weren't installed correctly. On this particular engine, the exhaust cam drives the intake cam via a gear, and also drives the distributor. If that's off 1 tooth, everything will be messed up, including the ignition timing. I'm looking at the factory service manual as I type since I own a 94 Corolla.
I never worked on one of those, but most engines have marks on the gears that you use to get the cam timing right. Your cam(s) can be 180 out of sync if you took the the cam system apart and put it back together without 1) Paying special attention to positions, or 2) use marks on gears to keep things timed properly.
I agree. Same with the distributor. You can check it a thousands times and think it's right, but if it's wrong, no start. Especially if the camshafts themselves weren't installed correctly. On this particular engine, the exhaust cam drives the intake cam via a gear, and also drives the distributor. If that's off 1 tooth, everything will be messed up, including the ignition timing. I'm looking at the factory service manual as I type since I own a 94 Corolla.
sounds like it got so hot that the rings lost tension.
finalyzd, the camshafts have 2 sets of marks: installation marks AND TDC marks. When you're placing the cams into the head, you need to align the 2 gears via the installation marks, not the TDC marks.
BTW, you do know for sure it is getting gas and spark?
Originally Posted By: AVB
I think if it was the valves, the compression readings would be off.
If the valves are off by 180 the compression would be good.
I think if it was the valves, the compression readings would be off.
If the valves are off by 180 the compression would be good.
What I was refering to was valve adjustment or seating issues. If the crank is 180 off from the cams, the valves would be closing at BDC instead of TDC. But depending on cam timing it could still make compression, but it would be pulling vacuum through the exhaust and blowing exhuast through the intake.
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Originally Posted By: AVB
Did the car run before you pulled the head?
It was a friends. Radiator was leaking. They never checked it. Finally the headgasket blew. I tried starting it but so much water was in the cylinders wouldn't kick over.. I've driven it prior quite a few time and it drove good.
Did the car run before you pulled the head?
It was a friends. Radiator was leaking. They never checked it. Finally the headgasket blew. I tried starting it but so much water was in the cylinders wouldn't kick over.. I've driven it prior quite a few time and it drove good.
Originally Posted By: Drew99GT
finalyzd, the camshafts have 2 sets of marks: installation marks AND TDC marks. When you're placing the cams into the head, you need to align the 2 gears via the installation marks, not the TDC marks.
I'm pretty sure that how he did it. But I will double check with him tomorrow. There's always a chance he could have made a mistake.
finalyzd, the camshafts have 2 sets of marks: installation marks AND TDC marks. When you're placing the cams into the head, you need to align the 2 gears via the installation marks, not the TDC marks.
I'm pretty sure that how he did it. But I will double check with him tomorrow. There's always a chance he could have made a mistake.
Originally Posted By: Chris142
sounds like it got so hot that the rings lost tension.
I hope it isn't rings. Do not want to take this thing apart.
sounds like it got so hot that the rings lost tension.
I hope it isn't rings. Do not want to take this thing apart.
Originally Posted By: JimPghPA
BTW, you do know for sure it is getting gas and spark?
.
We used a spark plug checker and cracked a fuel line then cranked it. Definetly got fuel(all over my face) and the spark plug checker lit up but it was weird looked really weak.
BTW, you do know for sure it is getting gas and spark?
.
We used a spark plug checker and cracked a fuel line then cranked it. Definetly got fuel(all over my face) and the spark plug checker lit up but it was weird looked really weak.
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