Z-ROC28

Hey guys. I've been drivin' my 91' RS Z28 clone for two years looking for a LT1 or LS1 car. I just happened to find a 97' SS sitting in a repo lot waiting to be sent to an auction. I found out the bank that owned the car sell their cars privately if someone is interested. I ended up getting this car for $4,000 in great shape. One minor paint flaw on the back bumper, no cracks, no rip in the seats. It has all options other then a 6 speed. Car has 181,100 miles but I'm figuring they are highway miles. Service Engine light was colored in with a sharpie. The car had an oil leak from the oil pressure sending unit.

- First problem: Engine has a miss on cylinder one. I've had it in the shop. Tested the sparkplug, plug wire, and injector. It's still missing. So I guess I'm getting ready to run into that famous opti-spark problem?

- Second problem: First night I took it out, I came to a stop light (put 20 miles on it since we picked it up). I accelerated and as soon as it hit second gear, it shut off. It took about three turn overs to get started again. The next day in the middle of lunch hour traffic I was all excited to take the car out to lunch with the t-tops off, i get a minute down the road and it does it again. I throw it in N and crank it back up to keep from backing up the already backed up traffic, shuts off 15 seconds later, cranked back up kept rolling, shut off again. This time it didn't come back on. I backed traffic so far up I couldn't even see the end of the line and there was already a wreck ahead of me. So the car got towed and put in the shop (from where i mentioned earlier).

We kinda figured the leak from the Oil pressure sending unit was causing the fuel pump to turn off so we have the unit replaced. It just shut off on me again earlier today. So i went to auto zone and bought a fuel pump relay and replaced it. I guess I'll see later on today if that fixed it or not but anyone else had this problem?

socal

iTrader: (1)

are you sure it fule and not the ingnition

Z-ROC28

Well that's what I'm not sure about. It felt like it was wanting to start when it broke down but it didn't the slightest bit start. I figured it wasn't getting any fuel. The ignition fuses are fine too.

z28hustle

check the opti first or just go ahead and replace it and then thats out of the way.. seeing as how the car is parked and not going anywhere anytime soon regardless i would get that out of the way first. chances are the previous owner didnt replace it or did a half *** job of attempting to replace it.. anyways once you know that works you could make sure once again youre getting spark to all of the cylinders and then move on to the fuel.. i bet youve got about 82790872 little things about that car that are going to start pissing you off real soon but the best of luck to you..

Razor_Blade

iTrader: (8)

Change the fuel filter.

ThoR294

iTrader: (6)

with that many miles on the motor, i would check your compression on the cylinder thats missing. i was stupid and chased a misfire on my friends car for a long time, tried everything... so i picked up a compression gauge, and sure enough, it wasn't squeezing enough

LS1_K1DD

iTrader: (3)

Yeah, with that many miles and who you bought it from you may find lots of things wrong. Start with the basics for the safety of the motor and reliability. Change ALL the fluids. ALL. Including tranny flush/rear, oil, all filters(fuel etc.), and then throw a new opti/plugs/wires in it. Also take a look at your fan belts and make sure the grooves aren't being eaten off by a pulley(happened on my 96 at 141k). And also my guess would be fuel pump. But as stated above try a compression test!

Z-ROC28

Yeah, we've checked everything that should have been checked. Oil was just changed. New fuel filter. Even popped a new injector on that cylinder. Tested the plug wire and plug, then even put a new spark plug in it. Tonight before I went out, the car did what I was afraid it was gonna do. Not run. I went out to the garage, turned it over a few times and nothing. And it sounded just like it did when it broke down on me the other day. I took the 91' out instead and I got a call from my dad saying he had just randomly got it to start. He has a theory it might be the ignition module, so he popped the one off a spare LT1 intake we had and put it on. I just got home so I havn't started the car yet and I guess I'll see what it does in the mornin'. I'm just glad it didn't start and get down the road then break down.

Forgot to mention, we did run a compression test before he tried putting a new spark plug in. It came out about 155-160 psi. Fuel pressure is also fine on the car. The pump works fine, just had a new filter. So what else?

Z-ROC28

Okay well, I was just heading home and the car shut off just after it hit third gear... So now we know the ignition module didn't fix it... It didn't want to start for about three minutes. I sat there for a minute trying to keep myself from cracking my dash . I popped the hood and just took a look at it looking for any cut wires or anything... I didn't find anything but I did tug on a few. I got back in the car and tried one more time. Then it started like it normally would any other day. I got it to the shop that was working on it the other day before i broke down again. The mechanic is my dads good friend, so we left it with him hoping it'd shut off on him so he can find out what the problem is. He told me there was a code that popped up for the MAF and EGR. So he took me back home and I gave him the MAF and ECM off the 95' LT1 I have. (If) it is the ECM going bad, will that ECM be the same? It came off a 95' police interceptor Caprice. Anyone else have any theories?

LS1_K1DD

iTrader: (3)

I don't think the 95 will be the same. If i recall correctly from what i've learned on here the 95 will be OBD1 and the 96-97's OBDII. Throw a new MAF on it and maybe try a new knock sensor while your at it. Also didn't you say you checked all EGR/Emissions lines?

XxApollynxX

iTrader: (2)

Put an Optispark on it like every one else has been saying, Opti, plugs, wires, waterpump, coil.

LS1_K1DD

iTrader: (3)

Waterpump should have nothing to do with it. The car isn't overheating.

leadfoot4

iTrader: (1)

Does the car have the VATS system? Maybe you have a bad ignition key.

Z-ROC28

A problem with the vats crossed my mind, but I read on LT1tech.com that if the VATS trips it shuts off the starter and fuel pump. Both the starter and fuel pump work when it does break down. It just seems like it's not getting any ignition. I left the car at the shop so hopefully it will shut off on him and he can figure out what is causing it. I would just buy an opti and water pump but knowning my luck I'll end up waisting 600-700 bucks on that and it still messes up. Im just about sure the opti is causing the misfire on cyl. 1. Thanks for all the feedback guys. Im probably just gonna end up buying the opti/pump for the hell of it anyway so I don't have to deal with it later. Can someone also tell me why LT1 plug wires cost $120?!

Bad93TA

iTrader: (2)

opti?

Z-ROC28

Well the car finally messed up for the mechanic. He said it was getting no spark when it messed up. He thinks it is the crankshaft positioning sensor. What do you guys think?

LS1_K1DD

iTrader: (3)

^Try it out. And throw an opti in it.

infinitebird

iTrader: (11)

I think maybe you need a new mechanic lol.

The crank position sensor has absolutely nothing to do with delivering spark.

mtperformance

iTrader: (7)

You called that one like it is.

LT1-DAN

With that many miles i would Not do a tranny flush, let alone change the fluid!!!