This is long but gives all the details! It is a 1993 vett LT1 in my 71 chevy SWB.

Ok here is what I have going on right now. I started my build (project slow build) about 7yrs ago. I bought the motor with stock computer, chip and sensors then I bought a Painless Harness for that motor. I have bought maybe 5 or 6 painless engine harness's in the past and 12 or more full vehical harness's and I have never had a single problem. I tried to get it to fire and no luck. It would crank but now fire unless I unpluged the fuel pump relay then it would pop off with the fuel sitting in the system. I called painless and they said their harness are all checked before going out and they feel it is in the computer or chip.

So I sent the computer and chip off to Speed Sean Wiring in TX and Zack did a re-burn on the chip and dumped the VATs and bumped the power a bit. I got it back and teh same problem was still hapening. I was pissed to say the least so I put it all in the corner of the corner of the shop and that was it.

Now jump forward a few years untill SEMA 2006 when I ran into Lance w/ painless and gave him a full run down on whats going on. He said to send him the harness (offered to pay for shipping but I declined) and he would personaly check it out. I did just that and a few days later he calls me and says they can find nothing wronge with it but they did up grade the trany plug to their new design. He also got all my trouble info again and started calling other enginiers trying to find out what it could be. He cals back with a posible problem of my fuel pump being bad and drawing too much power from the system and not letting the computer fire off. I was using the stock pump from the salvage yard I got with the motor so I plumbed in my new system and tried it again and it poped right off

But it would not stay running It would cycle on and off but if I played with the throtle I could get it to stay running but you could still hear it shut on and off real quick. I call Lance back and he sends me to Jason for a new ear to try and figure it out. Jason spent about 1hr the first time just double checking everything to see where he was starting off from. We could not find the problem but he felt it was in the chip or computer but mainly the chip. So I spend another $135 on a remaned computer (after $600 for teh harness and about 3-500 on the re-burn) that I could return if that was not it. Guess what it was not it!! I call Jason and Lance back tell them the news and they offer to send me a chip to try out but find they are out of stock on theirs and offer to call around for me trying to get one.

I get a call today letting me know they found one they can ship off and then Lance makes me a great offer. He know how frustrated I am at this point and he just wants me to be happy so he offers to sell me one of their new Perfect kits at a great price. This way it is all their system that thay can stand 100% behind (instead of three diferent sources I have now) if their is ever a problem. Also this system sounds much better than what I would have if mine ran right from the start. So this is were I am at and I am just looking for feed back from anyone who has some.

Thanks and Merry Christmas!

Kevin
LFD Inc.

That sounds frustrating!!! That's part of the reason I went with a RamJet, as I knew there would be problems I didn't want to have to deal with.

Did you get the 66103 (or 66104) kit, because it looks to be very promising to me. I have always wondered how much of those little things from the original harness would make the transfer hard, and if this kit is one place to plug everything, it has to be a whole lot simpler.

As for your problem, it sounds like something with the relay... I'm sure you pulled your hair out tracing every last wire a hundred times, but for it to pump sometimes and not others...frustrating!!! Did you try to bypass the ECM control of the fuel pump, or is there some sort of feedback that checks to make sure the pump is pumping before it fires the ignition?

lt1 is a good powerplant for any vehicle however if i was gonna do it up i believe i'd go for the ls1 engine myself, thats if money is not much of a factor, i am friends with a guy who puts lt1's and ls1's and so on in whatever customers request he does his own wiring and all and he's darn good at it, he was telling me that if you run a stock lt1 with everything near stock its just not torquy enough for a hot truck, but however after i put an lt1 and t56 six speed in my 87 s10 i found it to be plenty of torque for it but then again it wasn't stock and near 400hp in a light truck is just plain fun, but good luck again on your project because nothings cooler than one of these vintage trucks with a modern fuel injected powerplant

Well it is not a relay or a fuel issue. The ECM is shutting off and on for some reason. I can bypass the fuel pump relay (only relay in the system) and the computer still comes on and off!

As for the LT1 vs LS1, my 70 2WD blazer is geting the LS1 with a charger but this truck has the LT1 now so it is being used. Whew I started this project and bought the motor LS1's did not even exist yet as far as a swap in motor. That is how long this thing has been dragging on. My LT1 is rated at about 360hp right now and the Painless kit will bump that a bit. It is being built for a DD and weekend travel vehical so decent MPG and reliability are all that is needed for this toy. Thanks for the input. Here is a pic.

Kevin
LFD Inc.

Kevin,

A buddy of mine was having a similar problem with his TPI motor. Changed chips, computers... everything, but nothing would work. After a month of trying to figure it out, I happened to look at the connections going into the computer, wala!!!! One of the pins in the connector was backing out causing a broken connection. Fixed the pin, fixed the problem. That's the crazy part about electricity, it doesn't take much to make you pull your hair out. Do you have 2 Oxygen sensors? I got the connectors crossed one time and it caused the engine to do some crazy stuff. The only other thing I know to check would be the oil pressure cut-off switch. I've known them to go bad and create problems. Good luck.

Rob

Yeh I have been over all that stuff a few houndred time trying to find anything at all. No luck so far. The perfect kit should be here this week. Painless made me too good of a deal on the kit to passup so I will see how it is soon.

Kevin
LFD Inc.

Glad to see you working on this project again!:metal:

Jay

Yeh it is going slow but that is alot faster then it has been going!

Here is the new harness! Check out how small the new computer is (left of the can) compaired to the stock one (right of the can). I will try and get it in this weekend and see if it all works!

Kevin
LFD Inc.

That actually looks pretty smart.

All that keeps rattling around in my head about your prob is that there has to be some sort of feedback to the computer that isn't working out right. Something was telling the computer that something wasn't right, or else it wouldn't have been cutting out. I assume you checked out all the sensors (and even replaced a few).......I just hope you don't have the same issues........Shhhhhhhhhhhh, I did not just say that........:rolleyes:

Did you list a part number for that?

Thanks,
Jay

That actually looks pretty smart.

All that keeps rattling around in my head about your prob is that there has to be some sort of feedback to the computer that isn't working out right. Something was telling the computer that something wasn't right, or else it wouldn't have been cutting out. I assume you checked out all the sensors (and even replaced a few).......I just hope you don't have the same issues........Shhhhhhhhhhhh, I did not just say that........:rolleyes:


:dohh: :lol:

Well I put the new system on tonight and it fired right up and ran great! It has a slight stumble when wrapping the gas so I need to check into that or it may just be that it needs to learn a bit first. So far so good!!

Kevin
LFD Inc.

Well I put the new system on tonight and it fired right up and ran great! It has a slight stumble when wrapping the gas so I need to check into that or it may just be that it needs to learn a bit first. So far so good!!

Kevin
LFD Inc.

Great news! You might want to run a bottle of injector cleaner through it, since it's been sitting for so long.

R