My 88 convertible has a starting issue, It cranks and cranks and cranks, I work the throttle (as if a carb) and it'll sound like it's flooded, hit and miss. Hit and miss. FINALLY after anywhere from 5 - 20 seconds It'll fire. I've had times where after turning it over for about 10 seconds I'd hit the starter again and about 3-5sec. it'll fire right up. The car has *cough* 127k on the Odometer. I know it smokes a little on start up and it also needs rockers adjusted. So before I start driving my baby as a daily driver I'm going to have a the valve seals done. But WHAT'S CAUSING MY STARTING ISSUE!?!?!?!

I heard about a cold start valve... could this be an issue? Heard about a fuse behind the DIC... checked mine just to be sure but all those fuses were good to go.

I was thinking tune up, that's one of the first things I do with any car I get.. along with tires, hoses, and belt(s).

You're help is respected and appreciated!

Thanks,
~Dane

 

...welcome to the club!..i have an 88 coup and have been chasing this problem for a long while now. i have changed plugs, wires, cap, rotor, timing is ok, no vacuum leaks, no leaking injectors, new coil, ignition module and pick up coil, good fuel pressure and fuel pump and relays,, fuel filter, no codes on computer......2 days ago i took off tb and cleaned as well as cleaned and "adjusted" iac - pintel - seat, tps is fine....not a battery or alternator or vats issue of course......

....the car will crank for 2-4 seconds before it starts and will actually start "faster" sometimes if i hold the gas pedal to the floor. that fools the ecm into thinking that the car is flooded and cuts back on the fuel. however, is it a "way too much" fuel issue and the ecm cuts back on the fuel when i do this or a "way too little air" issue and it gets more air when the blades of the tb are wide open? or neither?....there is a cold start valve (csv) in your car as well as mine that is "energized" by a switch at the bottom section below the tb....that switch will keep the csv "in the circuit" as long as the temp of the engine does not exceed 95*......that or the switch could be a contributor....i have so far checked neither in my case.......i have checked the fuses behind the center dash console and all is well there too.....i have not started the car in 2 days as i have been to busy. but, will let ya know....

 

Does it do it all the time or when hot or cold? If cold, get a test light and disconnect the CSV connector and touch the terminals in the connector. See it lights up while trying to crank, but the engine temp has to be below 95*. If the engine temp is higher the light will not come on.

 

...rrt, who is this question directed at?

 

To original poster.................


I would start with the fuel pump. Get a pressure guage for it and put it on before you start the car to set if the pressure goes up when you turn the key to turn on your lights, radio ETC.

Also keep an eye out for how fast the pressure dissipates when you shut the car off.

Do a couple test , post your results here and we'll see if it resembles fuel pump issues.

 

Test the cold start valve and fuel pump relay, both cause similar symptoms.
http://members.shaw.ca/corvette86/Co...rt%20Valve.pdf
http://members.shaw.ca/corvette86/Fu...mDiagnosis.pdf
http://members.shaw.ca/agent86/Fuel%...elivery-8A.pdf
http://members.shaw.ca/corvette86/Co...0View%2086.pdf

 

.........i have looked at the csv and the connector that goes to it....i have given it a little tug but am affraid to do much more for fear that i will break something......how does the connector to the csv come off and detach?

 

Just another thought: Any chance the rocker adjustment is causing some valves to remain open? This can make for hard starting. This may not be too likely a scenario for hydraulic lifters though.

If its flooding, it probably won't ever start unless extra air is introduced and the fuel is cut off. Have you tried cranking a WOT, as this cuts the injectors for flood clearing. purposes.

Otherwise, if there's not enough initial cranking fuel, it may take some time for the fuel to accumulate into a rich enough mixture. My car requires alot of cranking fuel for the first start due to cam overlap.

Subsequent restarts when the exhaust is no longer full of air require much less fuel, so I have my cranking fuel set up to be a balance between quick first starts and trying not to flood on quick restarts.

Long cranking off throttle, then eventually starting would be an indication of not enough fuel (assuming ign is ok).

Long cranking that improves with WOT would indicate too much fuel and flooding during 1st crank. This is unlikely since it requires a lot of extra fuel, but a sticking injector or CSI could be the culprit.

 

I had a similar problem with hard intermitant starting. After chasing it for a while, I found the starter was dropping the voltage down below 11 volts. I replaced the starter and the problem went away. There was also a 34 code asociated with this one. Hope it helps.

 

...whom is this directed to?....the original poster?

 

All Great info! When I've tried to start it at WOT, The car sounds like it's flooded out. (as if I had over pumped a carb and am trying to clear it out) BUT it wont start at WOT I haven't found an answer to an easy start for it. HOWEVER, the Starting it at 11V it'll drop off considerable to a volt less after trying to start? (I'll confirm this when i get a chance.. memory's a little rough) I feel it's a injector issue but yet I'm no mechanic. I'll see what I can do about getting a fuel pressure gauge, and try the test light this weekend. I'm going to go out right this second and put a charger on the car because I know it's at just under 11v. It'll drain itself off when starting, and see what happens with a good solid charge with and without the charger as a booster. I'll post what happens when I get a chance.

Keep the helpful comments rolling in

 

You can check whether your injectors are leaking (and/or causing a flooding condition), by reading your spark plugs. No gauges needed. An even easier way is to prime your fuel system, then as fast as you can, take the plugs out (since you have an L98, its not too difficult to do that). If you find any that are damp...well that's your answer.

 

I put the charger on and tried to start it wouldnt 'pop off' so I bumped the starter again and it fired right off like it should've the first time. Started it with 13.2v and it seemed to spin off much faster and fire quicker but still the first initial start of the key was a long duration. Also after it warmed up I tried to start it and It fired right up within the first 3-4 seconds. So the initial start is the one that's the problem it appears.

I'll try that next nice day outside.. been raining to much to actually get something done outdoors. This will be the first test I do. I have a shop locally that said they would gladly take a look at it for no charge and give me an Idea of what it needs. (trusted shop, I send all my cars there)...I like tinkering too...

 

From your description, it sounds like you need more cranking fuel, for whatever reason. This can be handled easily in a custom tune, but you may have some existing problems with the CSI or normal fuel delivery.

Here's an example of what works for me, but I haven't had a chance to test at low temperatures. (Note: CSI has been removed). With these settings, my car fires in approx. 1 second on the first crank when cold.

Crank Fuel Pulse Width Vs. Coolant Temp.

Deg. C msec
-40 99.6
-28 99.6
-16 75.0
-4 50.0
8 39.5
20 30.1
32 21.1
44 11.7
56 11.7
68 11.7
80 11.7
92 11.7
104 11.7
116 11.7

Here's a normal '88 cranking fuel table for reference:

Crank Fuel Pulse Width Vs. Coolant Temp.

Deg. C msec
-40 89.8
-28 80.1
-16 30.1
-4 19.9
8 12.9
20 7.4
32 7.4
44 7.4
56 7.0
68 6.6
80 5.5
92 5.5
104 6.3
116 7.8

 

Sorry Mail Man, my first post was directed to the original poster. You will have to release the clip that hold the connector on and pull the connector off. It looks the same as the other 8 injectors.

Vetster, I would check the CSV harness if you haven't yet. It gets it 12v from the starter solenoid and is controled by the thermal time switch mounted on the front of the intake, as mentioned. The ECM does not have anything to do with the CSV as it does with the other 8 injectors. Only way you will know is to test it as I suggested before. If you don't get the 12v at the CSV harness connector, you can check for 12v at the thermal time switch. The CSV not working will cause a longer than normal starting time when cold (<95*f), but will not effect starting time when hot (>95*f).

As for what Agent86 stated. The fuel pump relay could also be at fault. When you turn the key on, the ECM sends signal to the fuel pump relay which sends 12v to the fuel pump to prime the fuel lines for 2 seconds (you can hear a humm when the key is turned to "on"). If you don't hear this, you need to check the fuel pressure and see if there is any pressure when the key is turned "on" and before starting the engine. After cranking and the oil pressure reaches 4 psi the oil pressure switch will close and send 12v to the fuel pump. When you start when hot there should already be fuel pressure and enough to start the engine quickly.

Do some test and see if it is fuel related.

 

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
***Sorry Mail Man, my first post was directed to the original poster. You will have to release the clip that hold the connector on and pull the connector off. It looks the same as the other 8 injectors.

**no sweat!..i thought i was starting to hijack the thread anyway....(ps, what clip!?).....you wrote "...but will not effect starting time when hot (>95*f)...".....so if my car cranks long when hot, is it safe to say that csv and switch are not my problem?

 

Yes, any engine temperature above 95*, means the thermal switch will not send the voltage to the CSV connector and CSV. You can check it, but if it cranks and starts as long hot, as it does when cold the CSV is not the problem. There is a clip that holds all the injector connectors firmly to the injector. The one you have to pull loose to get the connector off the injectors.

The CSV thermal switch will send the 12v as long as the engine temp is below 95* and as the engine temp gets close to 95* the thermal switch slowly stops the 12v to the CSV harness. After 95* engine temp the CSV is no longer functional. The CSV system works only while the starter is ingaged and then only for a short period of time depending on engine temp.

 

thanks for the reply...i was going to do the tests this morning assuming it doesn't rain but, looks like neither is the problem..hell, i have replaced everything...now i am out of luck!..ugh!

 

UPDATE.......i ran a wire from what appears to be a tan or brn wire at the csv to battery ground and the car starts right up....so, it appears that it is the csv temp switch at the front of my block that is bad.....SO FAR SO GOOD......

 

Update for me as well.

I found by bumping the starter for a couple seconds then start it, it'll fire right off.

Any Ideas to that one?