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I have assembled a 1985 Corvette engine. New timing chain, re seated the valves, New ECM and PROM, new module, new spark suppressor, new TPS, New CTS, New O2 sensor, New fuel pump, cap rotor wires and plugs.
When I crank the car the fuel pressure, new FPR, is 40 plus pounds. My timing light says I have spark. TPS is 0.57 volts. I am going to pull and re install the distributor this weekend. When I crank the car the spark plugs are black and covered with fuel, not wet just black soot.
So assuming that I do have the distributor in correctly. Any ideas.
Oh and the car has run a few times. But, not well. I think it had a vacuum leak. Which I think is fixed. IAC?
one thing that throws some folks for a loop - when the timing gear marks are matched, that is across from each other during installation, the engine is at TDC NUMBER 6 CYINDER. question - did you drop your distributor in at that point, or did you rotate the crank one full turn to get to #1 TDC?
Funny thing about this. A couple of years ago I did the timing chain in my 1984 Corvette. Lined up the marks and no start. I called the manufacturer and they said. You have to rotate the cam 180 degrees. And I said " Why isn't that in the directions" to which they replied " WE keep asking them to put it in". So I did the rotation. And then I did it the old school method. crank the engine with no plug in number 1 cylinder. Big whoosh of air check the timing marks and install distributor. But, I am going to re install the distributor this weekend. Frankly it is the only thing that makes sense. But, I thought that there maybe some special feature of the 1985 Corvette that could cause this problem. So I thought I should ask.
I have seen people with car stopped and will not run. So like I said never hurts to check.
...but, I thought that there maybe some special feature of the 1985 Corvette that could cause this problem.
nothing special about the 85 corvette L98 engine - just one of the million or so, first gen small blocks out there. good luck - probably just a timing thing -
Does the 1985 L98 get a pulse from the distributor? I thought that some of the L98's need some reference signal from the distributor as to when to fire.
Clean those plugs off really well if you are going to use them, that contamination is hard to remove sometimes. I use a air powered mini sandblaster made just for spark plugs. (I have a Two-Stroke Motorcycle, that is why)
When I install my distributors I generally rotate the engine until I see #1 coming to the top of it stroke and then keep rotating until I see the timing marks. I rotate (distributor Clockwise) it until it comes up to 10* BTDC and then I slide the distributor in with the rotor pointing at #1 which is about 5-5:30 location. I did it recently and the 1968 C3's 427 roared to life with the first turn of the starter when I bumped it so it works fairly well.
I have never tried starting an engine that was 180* out, that has to be a challenge.... No back fires or popping at all?
Good question about the backfires. No not really. Some misfires. It keeps sounding like it's going to start. And then no start. That's why we are trying the distributor.
Thank you
Does the 1985 L98 get a pulse from the distributor?I thought that some of the L98's need some reference signal from the distributor as to when to fire.
Clean those plugs off really well if you are going to use them, that contamination is hard to remove sometimes. I use a air powered mini sandblaster made just for spark plugs. (I have a Two-Stroke Motorcycle, that is why)
When I install my distributors I generally rotate the engine until I see #1 coming to the top of it stroke and then keep rotating until I see the timing marks. I rotate (distributor Clockwise) it until it comes up to 10* BTDC and then I slide the distributor in with the rotor pointing at #1 which is about 5-5:30 location. I did it recently and the 1968 C3's 427 roared to life with the first turn of the starter when I bumped it so it works fairly well.
I have never tried starting an engine that was 180* out, that has to be a challenge.... No back fires or popping at all?
just for grins and giggles, here's my no muss, no fuss, method for setting static timing - engine at TDC #1 compression, and the slot on the oil pump shaft at approx. 5:30 position. drop the distributor in squarely - that is, the four distributor cap screws parallel, and perpendicular to the engine's centerline. the coil connections should come off, exactly 90° to the left, or LH side. as you lower the distributor and just before the gears engage, position the rotor exactly toward the center of the LH valve cover emblem (no emblem - an imaginary line between the VC's rear mounting screws - either perimeter of center bolt). it may take a little wiggle-giggle to engage the oil pump shaft, but continue to drop and seat the distributor. because of the helical gear cut and the 13 teeth on the drive gear, the rotor will automatically turn CW about 28°, and point to the #1 firing position at 0° TDC. once the distributor is seated, rotate the distributor a few degrees CCW - not much - every degree you rotate the distributor, is 2X at the crank. ideally, you should be able to get within a couple degrees of the factory setting 6° BTDC. note: this assumes the distributor drive gear is in the factory correct orientation or position - if it is turned 180° and installed, that throws the whole thing off about 14°. if it's upside down, forget it -you'll never get it started - . there is only one correct, factory position when installing the distributor. install the cap and wires in the proper order - once started, grab a timing light and fine tune - for some reason, these things seem to run real good at 7 or 8° BTDC -
ideally when you're finished, your distributor orientation should look like this - L98 tuned port - L83's will differ . L83's may differ....
The only way the L83 will differ, is that the #1 plug wire routs directly to the LH side of the engine, rather than wrapping around the back of the distributor, as shown here
The only way the L83 will differ, is that the #1 plug wire routs directly to the LH side of the engine, rather than wrapping around the back of the distributor, as shown here
.
- I swear I read it somewhere - maybe a TSB or someplace - ??? for some reason, I was thinking the distributor on an L83 is not positioned or orientated like the L98 due to the configuration of the intake plenum. the factory had to deviate from the norm and orient the distributor assembly a little CCW for clearance around the lower intake manifold and upper plenum castings (???). having never owned a X-fire, and never turning a wrench on one - my bad - misspoke. probably should have said "L83's MAY differ."
Having never owned a X-fire, and never turning a wrench on one - my bad - misspoke. probably should have said "L83's MAY differ."
Probably shouldn't have mentioned the L83, since this thread is about the L98. But since you brought it up, you're not alone! I was cruising with a bunch of C4's, and we had a hoods-up show. Everyone was crowded around my '84, and many had never even seen a CFI engine! It's cool to watch the fuel injectors work. You can't do that on an L98!
1985 will not start
. there is only one correct, factory position when installing the distributor. install the cap and wires in the proper order - once started, grab a timing light and fine tune - for some reason, these things seem to run real good at 7 or 8° BTDC - 
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