Lost in the forest...time for a C4 rebuild
#151
Three Wheelin'
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If it made a boom 180 out that says you have spark and fuel... have you checked the idle switch? sure you made all the distributor connections again after re-setting it 180 deg? verify spark with an inductive timing light? verify fuel with a pressure check?
#152
Race Car
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From your video, it's got spark and fuel. Have you checked that both distributors are turning? Technically, it should fire and run on one but worth a check by unplugging each of the coils wires one at a time. Fuel pressure would be the next area to look. If fuel is just trickling in, it's enough to ignite but not to run.
#153
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Both distributors turned in sync fine when I had them pulled, belt was in good condition also. I only put new caps/rotors on.
I didn't check the idle control switch, I'll hold that down on Wednesday when I head back to my buddy's garage.
We verified all distributor wires after re-stabbing the distributors. I didn't feel a distinct "click" when I put the plug wires into the coils, but they look like a pressure fit, so didn't get too worried there.
I'll bring my timing light over Wednesday to verify all wires are getting spark/signal.
RE: fuel, the only thing that changed over the 2-3 months the car was down is I put a new Wong chip in and installed new fuel lines either side of the FPR. My plan was to see if I could borrow a fuel pressure gauge set from someone locally and put my OEM chip back in just to eliminate variables for now.
I didn't check the idle control switch, I'll hold that down on Wednesday when I head back to my buddy's garage.
We verified all distributor wires after re-stabbing the distributors. I didn't feel a distinct "click" when I put the plug wires into the coils, but they look like a pressure fit, so didn't get too worried there.
I'll bring my timing light over Wednesday to verify all wires are getting spark/signal.
RE: fuel, the only thing that changed over the 2-3 months the car was down is I put a new Wong chip in and installed new fuel lines either side of the FPR. My plan was to see if I could borrow a fuel pressure gauge set from someone locally and put my OEM chip back in just to eliminate variables for now.
#154
Three Wheelin'
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Having recently worked on the coils I'd definitely make double sure you have them seated. Use the inductive lite on the coil to dist wires and dist to plug.
#156
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Something must have gone awry during assembly, was checking a few things today and it backfired violently through the intake again. Which can only mean one thing, my cam timing is off. Pulling ancillaries off tonight to hopefully get the engine dropped Wednesday to get at the valvetrain again to see where I screwed up and hopefully find that my incompetence didn't cause anything to bend.
Thanks for the feedback, will keep you guys updated.
Thanks for the feedback, will keep you guys updated.
#158
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I swapped the OEM chip back in first yesterday, no joy, so put the Wong chip back in. It's definitely seated.
It's probably something silly like 1 tooth off on one of the cams, but I guess we'll see.
It's probably something silly like 1 tooth off on one of the cams, but I guess we'll see.
#159
Formerly turbotwoshoes
Rennlist Member
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When you seated the chip, did you insure that you removed the spacer chip socket that some ECU had. I can't give details, but this was an issue from about 5-6 years ago.... The orientation of the chip was also critical.....
#160
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There's the black "base plate" with the metal holes in it on the board and I made sure the notch in the chip aligns with the notch in that base plate.
If I remember correctly, if the chip is rotated 180* it could cause damage to the Motronic unit, so I paid special attention to that.
If I remember correctly, if the chip is rotated 180* it could cause damage to the Motronic unit, so I paid special attention to that.
#161
Three Wheelin'
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If it's making a boom, then the chip is seated correctly. An intake backfire can easily pop one of the many rubber boots off and give you a massive vacuum leak. That's the simplest place to start!
#163
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I dropped the engine and checked my cam timing, 4-6 was off so I reset that side, triple checked everything was in the 1.6-1.8 range (993RS cams). Still not starting, but it’s close. Wondering if my rebuilt injectors are now the issue. They sat for a few months before I installed them (in a ziploc bag), not sure if that would cause issues with them sticking?
At this point, I’m not sure what the issue could be.
#164
Race Car
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That actually could cause it. They shouldn't sit.
I was also thinking maybe to just trace all the wires and make sure you have it wired properly.
Also. Take out the coils. And on the bench, snap the wires in a couple times. If those are new, and the plug wires are new, there is almost no way to get the plug fully seated in-car, until they have been fully seated a few times on the bench.
I fly back to CT on Tuesday. So if you get really stuck and need a set of injectors I'll mail you my extra set. We just used them in Rus's car for the same reason. They have new seals thanks to rus..so we know they work and are good. If you need to try them once all back together, I'll lend them to you.
I was also thinking maybe to just trace all the wires and make sure you have it wired properly.
Also. Take out the coils. And on the bench, snap the wires in a couple times. If those are new, and the plug wires are new, there is almost no way to get the plug fully seated in-car, until they have been fully seated a few times on the bench.
I fly back to CT on Tuesday. So if you get really stuck and need a set of injectors I'll mail you my extra set. We just used them in Rus's car for the same reason. They have new seals thanks to rus..so we know they work and are good. If you need to try them once all back together, I'll lend them to you.
#165
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That actually could cause it. They shouldn't sit.
I was also thinking maybe to just trace all the wires and make sure you have it wired properly.
Also. Take out the coils. And on the bench, snap the wires in a couple times. If those are new, and the plug wires are new, there is almost no way to get the plug fully seated in-car, until they have been fully seated a few times on the bench.
I fly back to CT on Tuesday. So if you get really stuck and need a set of injectors I'll mail you my extra set. We just used them in Rus's car for the same reason. They have new seals thanks to rus..so we know they work and are good. If you need to try them once all back together, I'll lend them to you.
I was also thinking maybe to just trace all the wires and make sure you have it wired properly.
Also. Take out the coils. And on the bench, snap the wires in a couple times. If those are new, and the plug wires are new, there is almost no way to get the plug fully seated in-car, until they have been fully seated a few times on the bench.
I fly back to CT on Tuesday. So if you get really stuck and need a set of injectors I'll mail you my extra set. We just used them in Rus's car for the same reason. They have new seals thanks to rus..so we know they work and are good. If you need to try them once all back together, I'll lend them to you.
The wiring harness is folded/stuck in its shape and everything lines up where it should.
I thought the hall sensor (crank sensor) could have been the problem, so I readjusted that to 1.0mm still no go.
I pulled the injectors yesterday and am going to take them back to the local injector shop today to see if they're clogged/other issues going on.
Thanks for the offer, we'll see if my OEM injectors (which worked before I tore the engine down) just need another good cleaning.