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Please help, ( or buy my car) still won't start!!

B

bdisanto

Guest
Please see my other posts regarding my problem. My 87 vette will not stay started. It initial problems was that it would not stay started, it would idle rough and stall when I gave it some gas. After all the effort described below I now can get it started, but need to maintain a high idle with the gas pedal for it to stay started. If it stalls it takes forever to get it started. Just to stick it to me a liitle more, last night the starter went, ( I guess from trying to start it so often). I think the starter needed to be replaced any way, every once in a while I would get a nothing when I turned the key, but it always started after that.

I have changed or inspected all vacuum lines, clean throttle body, changed plate gasket, changed fuel filter, good fuel pressure, replaced both MAF relays, MAF sensor ok, checked all plugs & wires,( they were new anyway) New Battery, all fuses ok, new alternator. Any ideas guys, I need the help, the closest shop that I trust is a 60 mile tow?

I noticed a sensor unit that is mounted in the block, drivers side between the 2nd & 3rd spark plugs on that side, it has a green and white wire, the connection is broken, it looks to be a temp or oil unit. What is this? and could that be my problem?

Also, I get no codes ?

Thanks for all the previous replies, please help me, I am going nuts.
 
R

Ruby Rag Top

Guest
I had a similar problem on my '86. That turned out to be a loose connection on the multi-plug into the computer. However, one item worth exploring is a sensor which is located at the top rear of the block. It reads the oil pressure and if it senses that it is low ( this could be a true or faulty sensor indication) it cuts the engine to help protect it from running with no oil pressure. The sensor is located under the windshield wiper motor and is a real pain to get to. I found the easiest method was to remove the wiper motor and use an open ended wrench from the drivers side on the underside of the sensor. I do not know of a way to test if it is working or not, but a replacement does not break the bank. Maybe someone else can tell you if it can be tested or not. Be aware that your gauges can show a healthy oil pressure but this sensor can still 'think' it is too low and stop the engine. Best of luck and don't give up.:hb
 

cntrhub

Well-known member
Joined
Jun 17, 2002
Messages
390
Location
North Hollywood, Ca.
Corvette
Miss my '62 & '80 4- Sp. Vettes
Do the simple stuff first.

I can throw two simple tests at you for now. Have a fire extinguisher handy for this test. Crank the engine over while someone is spraying WD-40 into the intake tract. If the engine fires up and runs, it's a fuel problem. If the engine starts to die after it's running on it's own, spray in more WD-40. If the engine continues to run doing this, spark is not the problem. Stay away from starting fluids... it's too powerful to continue to keep the engine running and could cause internal damage!
The second test is vital. This will eliminate your other two basic causes for no engine start. Take a compression of all cylinders! Anything under a 100psi is rebuild time. No cylinder should vary over 12 to 15% or more between each other. This is one variable of having poor idle.
You have 3 basic things needed to make any engine run: Spark, Fuel, and Compression. Eliminate one and, well.....you know the rest.
 
B

bdisanto

Guest
I forgot

My vette has only 42,000 original miles
 

cntrhub

Well-known member
Joined
Jun 17, 2002
Messages
390
Location
North Hollywood, Ca.
Corvette
Miss my '62 & '80 4- Sp. Vettes
Milage means nothing. You could have a burnt valve or stuck (open) valve at that low a milage. What you are trying to do is eliminate the variables......never guess or assume. A good mechanic checks compression first.
We can take one of the 3 basics previously described (compression), and relate over 5 variables just for compression alone. 1. Brunt valve. 2. Blown head gasket. 3. Bent valve. 4. Stuck valve. 5. Hole in piston. 6. Stuck ring in groove. 7. Shattered rings. 8. Broken connecting rod.
It's basic "process of elimination."
 

-=Jeff=-

Well-known member
Joined
Feb 2, 2001
Messages
909
Location
Bartlett, IL. (Chicago Suburb)
Corvette
1990 ZR-1
the sensor on the driverside is for the AUX fan.


Have you checked the Fuel Pressure? your pump could be going bad.

How old are the wires.. do they arc?
 
B

bdisanto

Guest
New wires

The wires and plugs are new, installed 300 miles ago, I checked them for burns, fit, etc..

The wires do not arc.

I checked the fuel pressure and pump, everything is ok
 

maxrevs85

Well-known member
Joined
Dec 17, 2001
Messages
709
Location
Eaton Rapids, Mich
Corvette
!985 ,blue coupe, 4+3 Z51
Have you checked the timing , distributor cap ,rotor, coil, module? I know its simple stuff but its a process of elimination.
 

cntrhub

Well-known member
Joined
Jun 17, 2002
Messages
390
Location
North Hollywood, Ca.
Corvette
Miss my '62 & '80 4- Sp. Vettes
more compression diagnosis

Continuation of compression problems: 9. Flat cam lobes. 10. Broken cam. 11. Hydraulic lifter failure. 12. Bent push rod. Flat push rod tips. 13. Collapsed valve spring.
Sounds like you've changed a lot of parts so far and nothing seems to help. Is the compression something that also should be examined? This is the cheapest diagnosis that needs no parts to replace.
 

billd

Well-known member
Joined
Dec 9, 2001
Messages
88
Location
Denver,CO
Corvette
2001 red convertible, 1985 wht
another idea

Have you checked your cat? sometimes they can get plugged and not let out any exhaust. The old gosinta/gosoutta problem
 
B

bdisanto

Guest
Follow up

Thanks, I did have the compression checked, all cylinders are ok,
I also started to put in a starter last night, I needed one anyway and since the car is down I decided to put one in. I need to remove the front Y pipes to drop the starter, so I can check the CAT (s). Ecklers sells a cat system that eliminates the front cats includes a new Y pipe and a new rear CAT for $ 300, any comments, also does anyone know of anything better.

Thanks Again
 
S

Shadowing1985v

Guest
well on my car

i have replaced the ecm, ICM, TPS,I knocked all the stuff out of my cat, new water pump, radiator, eletronic spark timing comptuer thing,knock sensor, O2 sensor,spark plugs "rapid fires" spark plug wires, D cap and rotor, and i have 0 codes

im going to adjust my valves on sunday, when i do this,, and my car still runs crappy, i will tell u guy's,,,

my cyclinders do run from 100 to 135 psi

2 are like 105 orso,, and the rest 120's to 135's

i have small deposits of oil around the threads of my spark plugs
but not on the tip of the spark plug only the threads.

the thin is,, i'll tell u what my car is doing,, i can't spin my wheels at all i have no start out power,i can hit 135 mph, but takes for ever to hit those, speeds,,,
next thing is, my dad replaced the coil with camero coil with a 5.7 liter engine.,,, would this make a differance,, was that a bad thing to do.he said it wasn't,, i think it was. i think tis been my valves all this time,, i'll keep u guy's up todate. "like i said' i bought this car blew the head gasket 3 days after i bought it "2 years ago" had a guy fix it, and the car never ran good since. finall last weekend i notice my rocker arms were loose so now we are goin to adjust the valves
 
S

Shadowing1985v

Guest
umm, i just notice something

go check to see if your ICM is bad

go take it into a auto place store, "autozone" and have them test it mine was giving out a weak spark but the car still ran,,,

those can go bad in everal ways..
 

JOV

Well-known member
Joined
Jul 17, 2001
Messages
111
Location
Vacaville, ca, usa
Corvette
2019 ZR1 Blade Silver Metalic
I had the same problem on my 85 coupe and to make a long story short it turned out to be my EGR Valve stuck in the open position, normally this would set a code but in my case also there were no trouble codes............:beer :w
 

WhalePirot

Well-known member
Joined
May 9, 2002
Messages
2,942
Location
SoCA
Corvette
1984 White Z-51/ZF6-40/Shinoda body
spark check

Simple spark check: Use an unsulated phillps screwdriver, inserted in the plug wire of your choice, removed from the plug.
Hold it near a good ground and look for a healthy, blue spark, while a friend (or lover) cranks the engine. The spark should jump about 1/4". Don't do this too long, to preclude dumping raw fuel all over the inside.

The sensor near the WW motor is for oil pressure, and I believe it shuts off the fuel pump through a relay; one of two on the firewall nearby. Do you smell fuel fumes after all that cranking? Are the plugs real wet with fuel; hence fouled?

A cat can clog, esp with a very rich running engine. The first symptom may be loss of power at high RPM. Get the car running before buying an exhaust system! BTW, I like the TPIS system, which runs 3" tubes from front to rear.

At 40k miles, I suspect this is a simple, electrical problem, not compression or an ECM. It's probably a broken connection or bad sensor. The bear is finding it!

I'd not boast of destroying a CAT. It is a HUGE FINE from EPA to anyone who does it. I found that my car runs about the same with a good CAT as with a 'test pipe, so I run the CAT. The Vette ones and most new ones flow real well. I have a new '84 CAT on the TPIS system and my 406 exhales like crazy!

Good luck!
 
B

bdisanto

Guest
Update

Thanks for all the help! Nothing has worked so far. I replaced the starter yesterday, removed the exhaust system, cats look fine, nothing moving around inside, I have an industrial wet vacuum that blows air in reverse, blew air through cats, seem to be fine, I don't know if that a real test, just seems a bad cat would substantially restrict the air flow. I do neet a new reay y pipe and mufflers, but as suggested my main priority is to get the car running.

A new problem, now there is no crank, it started before I changed the starter, I knew my starter was on its way out so as mentioned in prior posts I changed it while the car was down, but still no crank. I suspect its the ignition switch, car will start if I pop the clutch while pushing it, I do hear the starter relay click while trying to start it. I bypassed the clutch saftey switch,still nothing. I ran a 12 volt supply straight to the clutch safety connector, motor cranked. GM issued a service notice on this condition. Apparently the original igintion switch/cylinder has so many problems they redesigned it and offers a new part that has better contacts for the VAT chip in the key ad also uses a longer key. I am told by chevrolet that if my engine cranks during the above procedure, and the clutch switch checks ok, it it the key or the switch.

By the way, when it was cranking, I had good spark, I agree Whale, I am not gong to run it without the cats.

JOV, I did have an code for an EGR vavle last year, it only came on during a trip from NY to Florida and back last year, never caused a problem, I cam home and reset the codes and never had a problem since. Maybe I'll change that to, is it located under the plenum, if so, how easy is to change??



I'll let you guys know, no one else shoud have to go through this pain and suffering!!!!!!!!
 

69MyWay

Well-known member
Joined
Jul 3, 2001
Messages
4,364
Location
Auburndale, Florida
Corvette
1969 Killer Shark
You have a dead VATS, that is for sure.

One thing I don't see mentioned here, and often over looked is the ignition module in the distributor. Those can be tested at many chain autoparts stores, and are only about $30-$50. They are not predictable. Yours may have a dead open contact inside that will close at certain temps, allow it to start, then fail again.

If yours is original (which I bet it is), it will be a cheap piece of preventative repair at the least.

This is the little tiny module in the distributor below the rotor.


Good luck!
 

vigman

Motor head!!!!
Joined
Feb 13, 2001
Messages
3,471
Location
Valencia, CA,USA
Corvette
88 Convert ( SOLD ) /1973 coupe 4 speed/1964 Vert!
Starter relay wiring/VATS

BZZZTTTTTT Disagree with Chris on this one!
( Oh no a conflict.........)


You Could have toasted the contacts on the starter interupt relay.

SO

The relay is located behind the DIC ( Drivers informational console ) in the center part of the dash... behind the console is the Alarm fuse and your HORN relay & the starter interupt relay.
(LARGE GAUGE WIRE @ RELAY)

The yellow line (Pin E) is the feed from the key switch.

The Dark Green White(PIN A) is the relay output heading twds the Clutch saftey switch ( or the tranny switch in the case of an automatic )

FOR A QUICK TEST ONLY!!!!!!
JUMP PINS A&E with a BIG paperclip and just BLIP the key ( Clutch in ) the paperclip will HEAT UP...DANGER about 10 amps of current!
If the Starter pulls in... TADA!.. replace the relay.

If not...continue....

The output of either of these switches is a purple wire which goes 2 places
1 to the starter post
2 to the fuse box and the START/CRANK line is the power for the cold start injector!


Now It's MY opinion.....

If you turn the key to Start
and you hear a CLICK behind the dash DIC panel.
BUT the starter doesn't spin.....

The VATS is OK BUT the relay is TOAST


SO.. back to the starter interupt relay.

The COIL of the relay
Pin C Yellow ( Hot in crank)
Pin B Dk Green ( Grounded when VATS is HAPPY)

You should hear this relay CLICK.... if you are unsure... use a test light and get across the b&c pins.... if the light lights Vats is happy!

Betting you starter was OK and the relay pooped out!

Vig!
 

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