Does anyone know of a good vette mechanic in Huntington Beach,Ca. I'm really needing some help with this 88 TPI I'm 63 years old and been struggleing with this monster and I'm about whipped. Put in new plugs,wires,dist. cap and rotor. The only way to keep it running is to feather the gas but it's not driveable.

 

Its still a mechanically similar Small Block Chevrolet Engine you are familiar with from the 1955 to 1981 when carburetors were still used.

Ignore the maze of wiring, hoses, and smog equipment at 1st.

You are still dealing with an engine that requires correct Ignition timing settings, Needs air, needs gasoline fuel, and corresponding correct camshaft timing.

Basics again are Air, Fuel, Spark, and camshaft timing(engine compression on approaching TDC Power Stroke Too).
If any of these basic essentials are missing the engine will not run or will run poorly.

I don't know of any good Vette mechanics in California.

But I am in Illinois and I am a Professional Mechanic and fantastic with working on Vettes too.

Many other talented home and professional mechanics on C4 to help you out likewise.

Brian

 

thanks when i put all the new stuff in i left the #1 plug out and put it on TDC then installed plug and wires. when i'm feather the gas to keep it running and get it to 2000 rpm and try to hold it there it pulsats between 2000 and 2200 just back and forth. How can i check the fuel presure at the fuel rail if it won't idle by itself?

 

If I could get just a little time off Id come look at it for you.
Im in the sfv

 

Did the engine run fair or decent before the ignition tuneup?

Perhaps you do not have the spark plug wiring or routing correct?

Question for you to ponder and ask yourself.

The firing order is 1-8-4-3-6-5-7-2, distributor turns clockwise rotation.
Same as since 1955 on all sbc & bbc cars and trucks.

You can check your fuel pressure yes on the fuel rail.
Fuel pressure should be around 41-47psi with the black vacuum line off the Fuel pressure regulator and cranking the engine over or running.

Brian

 

well before the tuneup it was spitting and sputtering at take off and when i was running about 30 and would nail it it would fall flat and take a couple of second to take off. so i thought maybe a tuneup would fix it.Yes on the wiring i've checked it at least 20 times and used a diagram. Thats another reason I had #1 plug out to get it to TDC. I've been messing with it for five days with what seems to be no progress and I'm beaten and bruised. I've owned this vette for four years and even though it has alot of miles on it i've tried to take good care of it.

 

Check the fuel pressure and make sure it is within specs.

Pull a single plug wire and install it onto a spare spark plug.
Crank the engine over and make sure that you have a hot bright blue spark present.
An orange spark means there is no current present just high KV.
A weak ignition spark will not ignite a modern EFI engine properly.

Check the TPS or throttle position sensor for correct operation.
A scanner or auto x-ray or a simple DVM meter set on Ohms will get the check done.
You can also backprobe the TPS and set your DVM on DC volts and check the idle voltage setting to WOT voltage present.
Any glitches or sudden abruptions in readings for OHMS or DV voltage output, You found a bad TPS on your Vette.

Make sure the air intake hose is tight on the MAF- mass air flow sensor.
Sometimes that hard flexible plastic hose will crack on the underside hidden from view.
That will cause "Rouge" air to be sucked into your vettes engine that the MAF will not read.
So the engine will run lean or rich at different times driving and cause sputtering / driveability problems.

You can unplug the MAF sensor too.
If the engine runs the same while reving it up in your driveway or a quick spin driving down the block.........
The BOSCH MAF sensor is likely defective.

Keep trying to isolate the problem(s).
You will succeed if you persist.
Or you can pay hundreds or thousands of $$ to a young auto technician that may or not fix your Vette.

Brian

 

ok i'm going to start over. Try and find DTC and make sure i have that right. I'll have to go buy a presure gauge to check fuel. I have a volt meter so i'll do that after i find TDC. Thanks for all the help as i'm retired and don't have a lot of money to waste. I really appreciate everythang thanks

 

Have fun troubleshooting today on your 88 Vette.

Keep smiling.

You will find out what the problem is on your car.

I am taking a trip to St. Louis today.

I will check back later this evening and see how you made out repairing your Vette.

Brian

 

I'd disconnect the MAF and see if it runs.

 

I checked TDC i'm sure it is right. I unpluged the MAF and it did not change anything. It still will not idle or run without feathering the gas. I also set a meter tester to ohms and checked the TPS it read like .047 and when i wot it went to zero if i did this right?

 

The TPS should read .54 volts +/- .07 with the throttle closed. WOT should read 4.5 to 5 volts. The voltage should increase from .54 to 4.5+ as you open the throttle.

If you "did the check right", and see 0 volts at WOT, it appears you have a bad TPS or TPS connector.

When I do a TPS adjustment, I backprobe pins a and b with pieces of wire, connect the meter to the wires, turn the key on, then check that the idle voltage is within spec, then open the throttle body to WOT and watch for the voltage increase.

The TPS basically tells the ECM where the throttle is so the ECM can adjust the pulse to the fuel injectors.

 

ok my TPS connector has three wires gray.blue,black so i have to check volts and not ohms is that correct?

 

well i didn't make any progress today seems like i just keep checking the same things with the same results. I'll check the TPS again tomorrow with a volt meter. Hopefully i can get real results. If theres any corvette mechanics in Huntington Beach,Ca i could sure use some help. I can't pay a lot of money because i'm retired but i can pay some

 

Sounds like a major vacuum leak, stab in the dark here.

 

Yes, you have to check volts. Backprobe the black and blue wires at the TPS and check for the voltages.

 

ok thanks i'll do that tomorrow

 

the TPS measured .435 and WOT it was 4.69 and with the MAF unplugged there is no differance. Still won't idle or run without feathering the gas

 

I agree. Your 'Vette is an 88 and 23 years old! Check all the vacuum lines throughout the engine compartment. There are both small hard lines around the TPI intake and rubber lines. The rubber lines run to more than a few places. They run to the cruise control, and even to the front left engine compartment, where there is a charcoal canister, that looks like a round ball. They also run underneath the intake plenum to the EGR as well.

Examine the lines carefully for cracks or detoriation. If the rubber rubs off on your fingers, then you should replace that line. You can also hear a vacuum leak as well. Unplug one of the vacuum lines and you'll hear the high pitched hiss of the engine sucking air through the opening. Replug and start listening around.

 

OK... The TPS appears to be good, but a little on the low side at idle..

Let's start again from square one....

1. You stated it was "spitting and sputtering" before the tune up.

2, You changed plugs, cap, rotor and wires.

3. You have verified timing the best you can.

4. No difference with MAF disconnected.

5. Have to feather the pedal to keep it running.

So, the next areas to check may be.....

1. Check your fuel pressure at the rail with a gauge. The schrader valve is on the right hand fuel rail with a black cap. When you turn on the key, you should hear the fuel pump run for 2 seconds and your fuel pressure should read around 40 psi, then hold relatively steady or bleed off slowly.

2. Have you checked for good spark? Pull a plug. What is the condition of the new plug? Has it turned black (carbon fouled)? Lay it on the exh manifold with the lead (wire) attached and have someone crank the engine.. Do you have a bright spark? Have you had the coil tested?

3. With the key on, do you have a full 12 volts at the bat connector to the distributor? Remove the pink wire and measure the voltage at the connector.

You need 3 things to run.. fuel, spark and air..

EDIT: After reading F22's post, did you disconnect or break the big vacuum line from the plenium to the power brake booster to gain access to the area while you were changing the cap and rotor?