LT1 hard to start
Once the car starts does it stay running? It will start even if the opti in off the dowel pin. I've done it twice. Thought it was lined up but would die everytime I gave it a little gas.
The other problem that I have encountered that matches your symptom is the hi res signal being gone on the opti and if I gave it gas or pumped it while starting it would eventually start. It would run too but you could tell it was a little sluggish and just generally "pissy". That points back to a bad opti or the harness that plugs into it. There are known for going bad too. Typically they set a trouble code if the hi or low res goes out but if it hasn't ran long enough that way it may not have set the code yet.
You can try spraying the harness that plugs into the opti down with some electrical cleaner. It will clean and absorb moisture in the wires. It's worth a shot. Otherwise, I say the opti is the issue, again.
EDIT: Ok I missed the part about it running great after started. Sorry. Is that your opinion of running great or are you familiar with an LT1 cars performance? I'm still leaning towards it being the hi res signal is not showing for the opti. It can run "ok" with the low res but starting will always be an issue.
I thought fuel pressure when cranking and at idle was supposed to be a minum of 48? I could be wrong though. Try cycling the key 4 times before you acually start cranking it over. If it starts right up I would say it's fuel related. If pressue is back to zero within 5 minutes I would say you are losing fuel pressue somewhere for sure and you're on the right track. However, if it doesn't fire right off after cycling the key, then I say go back to troubleshooting the opti.
The other problem that I have encountered that matches your symptom is the hi res signal being gone on the opti and if I gave it gas or pumped it while starting it would eventually start. It would run too but you could tell it was a little sluggish and just generally "pissy". That points back to a bad opti or the harness that plugs into it. There are known for going bad too. Typically they set a trouble code if the hi or low res goes out but if it hasn't ran long enough that way it may not have set the code yet.
You can try spraying the harness that plugs into the opti down with some electrical cleaner. It will clean and absorb moisture in the wires. It's worth a shot. Otherwise, I say the opti is the issue, again.
EDIT: Ok I missed the part about it running great after started. Sorry. Is that your opinion of running great or are you familiar with an LT1 cars performance? I'm still leaning towards it being the hi res signal is not showing for the opti. It can run "ok" with the low res but starting will always be an issue.
I thought fuel pressure when cranking and at idle was supposed to be a minum of 48? I could be wrong though. Try cycling the key 4 times before you acually start cranking it over. If it starts right up I would say it's fuel related. If pressue is back to zero within 5 minutes I would say you are losing fuel pressue somewhere for sure and you're on the right track. However, if it doesn't fire right off after cycling the key, then I say go back to troubleshooting the opti.
Last edited by kyoytey1693; Jul 24, 2012 at 11:30 PM.
Thanks for the info, this is my second LT1. I have had 4 LS1 cars. For some reason this one is my favorite. And yes the first time it ran great, perfect throttle response. The second time like crap because I forgot to plug the mass air flow sensor in. My next plan is the fuel system and plugs. Going to drain the redish color fuel out of the tank, change all the filters and put new plugs in it. And cross my fingers! 
It won't heat it up enough unless they test it at least 5 times. I had mine tested 3 times and it was nowhere near as hot as when I was driving. Red gas? Sounds nasty. And seriously, if you can't get it fixed, don't push it off a cliff, tow it to me. I'll pay the gas. :p lol
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alright guys here is an update! Still the same! Can't even get it to start now. I am out of ideas. Think I am going to pull the crapy LT1 motor out and give it to a local scap yard and then start building my LS motor to go back in it!
Opti, plugs, coil, ICM, wires, harness and fuel pressure. And still haven't found anything yet. Going to replace the opti with a msd and a msd coil pack. Take the intake off and clean it. Remove the injectors and rail and clean them up. Go over everything again and try to remove a lot of useless vacuum lines that were part o the smog crap. And then cross my fingers.
