RedBowTies88

It's alive! Had to siphon out all the old fuel and put in ten gals of 93. It's running running pretty good not perfect and it's idleing a bit high which leads me to think I have a vac leak but other then that and some good rust on the rotors she's about ready to roll

j-wireman

Good for you. Now, get out there and cruise!

oldalaskaman

run some good injuctor cleaner thru, seafoam being one, if you decide on new injectors, go with fic a vender on here, he can get them to you next day, includes all gaskets and o-rings, provides good support, and answers his emails at some pretty weird hours, good people too.

RedBowTies88

thank you!

I plan to add a full bottle of seafoam next tank and yeai always try to deal with forum vendors on all my forums they're almost always good people.

Still having some minor problems though hopefully you guys will have some more advise for me.

#1 is well, the fans aren't coming on this is a problem that exsted before i parked it but i forgot until just now i know they work because they come on randomly sometimes but they wont come on when you need them... i assume its just a relay/wiring issue issue.

#2 its idleing a bit high...and its compounded with speed. i tried like hell to find a vac leak but from the looks of it there isn't one... also at low rpm (800-1800 or so) it breaks up quite a bit and sometimes i still need to have the gas to the floor to start it...

thanks again everyone

pmihaltian

Here is a pretty good Super Tune-up spec sheet for your L98. When you complete each item, mark the date and mileage in the right hand column and continue down the list until you complete them all. Wheh you complete the Super Tune-up, your Vette should run great.

RedBowTies88

thanks, that will sure come in handy

ProjectC4

There's a fairly new book out on C4's written by an English guy, I forgot the title but I have it. He describes how it's a fairly common problem to have the fuel fill drain in the rubber surround near the cap plug up. If the car is outdoors rain can fill the surround then with expansion and contraction from heating & cooling get sucked past the fuel cap o ring and into the tank. He described a customer with a ZR-1 who came home after an absence, tried to start the car, car would not start so he left it for several months during which time the water corroded the pistons. Sounds sort of like your story.

If there is water in the tank I have had that on customer's cars, siphoned it all out, refilled but had wierd intermittant engine problems afterwards (stumbling, etc). I learned that I had to drop the tank and would find small globules of water running around in it. Flushing the tank and the fuel lines all the way up to the engine was the only sure way I was able to solve those problems. It stunk but I always had to drop the tank.

RedBowTies88

what are our pistons made of? not cast aluminum?


i see what you're saying and i hope this isn't my case but if it is so be it...i don't feel bad for myself after letting this go so long.

can anyone help my on the fan issue? as this is the most prevalent problem keeping me from driving the car at the moment.. thanks

ProjectC4

Depending on year the fans are controlled by either a thermostat switch or the ECM. In either case there is a fan relay, on my '84 it's on the rear of the left front inner wheel well. 2 small wires for control, 2 big for power. Try tapping it when the fan won't come on. Better yet, just get a new one, it's like $15 & cheap insurance even if the old one still works. Mine was intermittent, I took it apart & cleaned the contacts to get it to work temporarily because I had to order it online.
There's more than 1 style of relay. The later ones (88 & up??) had a more sealed electrical connection.

RedBowTies88

mines a 91...hmmm well i will definitely replace the relay i hope thats the issue but if not im assuming it will be the thermostat switch...

any clue on thats location?


thanks man

ProjectC4

I think that on the later models the fan is controlled by the ECM - the computer which controls the engine, so there's no thermostat switch. Look arond on here, I think I saw it discussed on a thread here.

C4 Monster

sounds like bad gas, you said its been settin for a year and a half?

C4 Monster

Sorry, failed to see a second page, Congrats on getting her runnin!!!!

floridamale

Check front of manifold for your switch on my 87 that is the location

OkieC4

#1 - Your 2 fan relays are on the l/h side of the radiator shroud, side by side. You should have 12 volts at the red wire of each relay at all times (Pin E). You should have 12 volts at the pink/black wire (Pin D) with the key on. If no 12 volts on Pin D with key on, check the 10A Gauges fuse in the main fuse panel.

If you jumper Pin E (red) to Pin A (black/red) at the relay connector, the fan should run. This will check the fusible links, the fan motors, and the G117 ground.

The ECM provides the ground for the norman relay operation based on inputs from the temp sensor, speed sensor and for the secondary, a/c operation. Does your secondary fan come on when you turn on the a/c?

The coolant temp sensor is below the u shaped rubber coolant line right below the throttle body. Check the connector and replace the sensor as needed.

Also, check your ECM "green" and "gray" connectors for good contact of the pins in the sockets or corrosion. The ECM reference voltages and ground signals all run through there.

#2 - You may have some leaking injectors, erratic TPS voltages, or a sticking IAC. Clean your IAC, Check your TPS voltages for .54 at idle, smoothly advancing to 4.5+ volts at WOT. The ECM voltage data for the TPS is also fed throught the ECM "green connector". Finally, check for fuel pressure decay at the rail.

RedBowTies88

Ok update guys, replaced the temp sensor right about the wate pump and that corrected the fan issue it also improved the cars idle/running 95% it's not 100% and still has a hickup here and there but she's running very well.

Thanks for all the help again. I'm gonna put another 500miles on it and so and if she doesn't completely come around I'll replace the injectors

RedBowTies88

UPDATE: Put about 400mi on the car and ts running like a champ... nice and smooth with the new oil and all the power is back. shes about perfect except for one small detail...

Whenever i make a VERY hard left turn (possibly right as well but if so not as pronounced) it stutters and kicks as if the fuel as turned off with the flick of a switch... straight line absolutely no problem and the turn has to be HARD like tire screeching hard.

anyone have any idea? ProjectC4, is that similar to what you were talking about?

ProjectC4

Yes, similar, the cars would run absolutely fine then tend to stumble or die when accelerating or braking, not when maintaining a steady speed straight. I don't remember the problem turning, but it could be the same thing, the water running across the bottom of the tank and getting sucked into the pickup.
Try it with a full tank just to make sure its not sucking air. Maybe if you make enough hard left turns you'll suck up all the water eventually. Put some dry gas in there too so at least it's a water/alcohol mix.

aklim

I'd just replace them. Yes I know it seems to be running right but you can't tell. My car was running right too. Took the injectors out and sent them off to FIC and one of them had a collapsed basket filter and was flowing way less than the rest. Without a test, all you have is SOTP which is, IMO worthless as a diagnostic aid unless it is FUBAR.

As a practice, I would have the injectors cleeaned and tested ever few years. Seafoam and all those "cleaner in a can" stuff is like sweeping a large room in the dark. You have a pile of dirt but you won't really know how much you cleaned and how much is left.

aklim

See if it does that with a full tank. It could be that there is no baffle in the tank and the fuel is sloshing around during the corners. Some have reported that but I have not eperienced it myself. OTOH, I have replaced the pump in the tank and got rid of the rubber thingy between the line and the pump. Also, IIRC, there was some sort of baffle around the tank.