Hello I am a new Vette owner, last week I bought a 1990 coupe for my wife. The car is in good condition but I have a couple things I need some help with. I am pretty well versed on turning wrenches and I have several race motors that keep me learning all the time. The car no longer has the L98 engine it has been replaced with a zz4. My first problem is when I get stuck in stop and go traffic the car will hit 250+* on the temp and the driver side electric fan is not coming on. The radiator is clean in and out, new water pump, new hoses, new coolant. Another thing I have noticed is that when I first start the car it can boil the tires for a block with ease but once it warms up it loses power, what is that about? The fuel pump, sock, and filter have been changed, I ran a can of seafoam in the fuel tank also. Friday we drove 5 miles to the video store and when we came out the car would not start. The car was not hot, it had spark but would not start, I had it towed home and the second we unloaded it the car started. I tested the module the next day and it was perfect and checked all the electrical connection and they were fine. Other then this I ordered a new compressor to get the AC up and running and I need to replace the electric antenna.

Other upgrades that I know of:
Holley throttle body
Holley fuel regulator
Lingerfeld Headers, cat back strait pipe

Guys I would like to thank you in advance for your help I am sure you are tired of the new guy questions.

 

I would check the fuel injectors with an ohm meter when the engine is hot. That could be the cause of the lack of power.
You need to figure out why the fan isn't working. Try connect power directly to it to see if the fan motor is bad.

 

GREAT!!! This is what I need guys. what wires do I trip on the fan to check it? I saw I had a wire off the fan heat sensor next to the oil dip stick but I put it back on and no dice.

On the injectors what should the Ohms be at? Do you check them could and hot?


Is there a easy way to change your spark plugs or is it just a beast?

 

I'd check the injectors with the engine hot, should be around 16 ohms. On the fan I'd just run some jumper wires from the battery to the fan motor.

 

Ok so if the injectors or a single injector does not read 16ohms does that mean I replace all of them or just that one? where is the best place to get new injectors, and what size injectors do I get? Do I need a special tool to remove the injectors? Will I need to pull the upper intake and if so what gaskets do I need to buy?

 

As we are all Corvette owners we are never tired of new guy questions, unless its about the 160 degree stat. lol.

I am not big on wrenching my car but could it be a relay for the fan that causing it not to kick in?

I have an L98 and the only plug that is a PIA is number 2 the others are pretty easy. I can not see why a mechanic would charge 2 hours labor for this job. I am glad I do it myself now.

 

I would like to do as much as I can by myself as I have two other engines that go in and out of the race shop and cost me a great deal of money all the time. Saturday I built a 496 for a friend to save him some money but that is the last time, it is just to hot to spend all day in the garage.

What is the best way to do the plugs, from under the car or on top. The driver side looks easy but the pass side looks bad, the car also has lingerfeld headers. Oh it has factory style plug wires are these ok or should I throw them out and use some other wire?? I was told the correct plugs for the zz4 motor are these AC MR43LTS

 

I know what you mean about being too hot, I did my first valve seal replacement 2 weeks ago and took me 7 hours in a garage that was 85 degrees.

I do my L98 plugs from the top and yes #2 passenger is a PIA. Most people use aftermarket wires form what I see. Maybe someone else can chime in here. I a noob when is come to wrenching my car.

 

What about this guys?

Friday we drove 5 miles to the video store and when we came out the car would not start. The car was not hot, it had spark but would not start, I had it towed home and the second we unloaded it the car started. I tested the module the next day and it was perfect and checked all the electrical connection and they were fine.

 

Do you have two ignition keys for it? If not get a second key made, be sure they match your resistor pellet. This can also be related to injector issues, fuel pressure regulator, fuel pump and fuel filter.

So start with the basics, look at the sticky posts from FIC and check your injectors. Pull the vaccum hose from the regulator and check for gas. Put a gage on the fuel rail and make sure it pressurizes and holds.
If you have no records change the fuel filter - it could be the original.

 

It could be the VATS system acting up. A lot of us bypass it. The Corvette catalogs sell a bypass jumper if you are not in the building simple electronics. You will need to know your key resistance value. Search on VATS there are lots of threads.

 

You can take the inner fender panel and wheel off the passenger side which makes those spark plugs easier to access.
Buy some of Summit's wires. They are good quality and reasonably priced.
A lot of us have used FIC injectors. Great service and good prices.
See their sticky at the top.
Here is a pic of my 91 just after I installed the Bosch IIIs. You do not need to remove the intake runners though. I had mine off to install some aftermarket runners.

 

I pulled a plug wire and had spark, at first I thought it could be the alram or key but when I had spark I new it was something else. The fuel pump is new the sock is new and so is the filter. Every once in a while it would try to satrt a little, just hit of one time. If I unhooked the battery for a while and then hooked it back up it would pop once. After a couple hours I said screw it had it towed home. When we unloaded it I turned teh key and she fired up no problem and has run fine sense. Now the wife is scared to drive it for fear it wont start. I do not like not knowing why something happened.

 

Maybe bad starter solenoid or starter.

 

No you misunderstand, it spun over just fine. Either it was not getting fuel, or the injectors were not firing for some reason.

 

Still stuck on your username

 

Nick name I picked up when I was younger. I wrecked my truck trying to shoot some crows out the window. Long story pretty stupid but the name stuck.

 

Anyone got any ideas about why the driver side electric fan is not kicking on? I can tell were the wires go to because they all merg into a wire harness of the driver side of the car.

 

1st get a factory manual , really helps .
1) Are you getting oil pressure when you crank ? A bad oil press switch or fuel pump relay can keep the motor from starting. If oil press isnt high enough or read high enough the fuel pump relay will shut the pump off. check that connection
2) run a hot wire from your bat to faN CONTROL ON RELAY @ hot wire out to fan. Fan runs , relay bad. Fan dont run, bad fan or ground at fan
3) test ohm injectors .They should ohm 12-16 ohms all +/- .3 ohms within eachother
4) on brake booster between Mas. Cyl. there is an adjustable rod .unbolt mas cyl but leave all lines connected if you can. check travel on rod and adjust if necc. that is if you dont have any leaks you'll need a manual to tell amt rod should be out. if you adjust, keep track of turns on the rod
Good luck . Hope this helps
Chris

 

Thank you very much! What is #4 all about? I do not have any breaking problems. The car runs super strong when it is cold but after about 1-2 miles it drops on power. I have the Corvette service man for my car. Where is the fan relay located on the 1990 vett?