C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Guess the Problem!

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Old Jun 30, 2016 | 04:35 PM
  #1  
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Default Guess the Problem!

As some of you are aware my C4 sat for 6 mo while I had the engine out

New (MSD OPTI sent back to MSD for rebuild and update)
New plugs and wires.

While looking at Pro Chargers
manual to see how the serpentine belt went on I noticed a paragraph that said "Do not use Platinum plugs"
Any one use them with Forced
induction? I already had them in the engine.
When I called ATI and asked why, I was told you can't gap them to .035. I had them at .040.
Anyway, back to my problem.
Took the C4 for an I-10 ride about 8mi. It ran fine until I got off the interstate, made a right turn and then it acted like it was running out of gas!
It showed half a tank!
Not trusting the gauge I popped
Into a Shell station and put another 5 gallons in it.
It seemed better after I left the station but then it started acting up again.
I guess maybe I should drain the tank?
I installed a K&N fuel filter before I cranked it up and put about 4 gallons of fresh Premium gas in it.
I'm not by the car but when I get back I'll check the extra fuel pump that came with the blower
and check the fuel pressure.
Any other suggestions ?
Just seems funny that it was fine on the Interstate.
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Old Jun 30, 2016 | 05:00 PM
  #2  
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Extra fuel needs more spark to ignite

Perhaps sitting so long gummed things up.

Did ProCharger call for larger injectors, or did they just crank the pressure up.
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Old Jun 30, 2016 | 08:31 PM
  #3  
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You can try to check fuel pressure while driving... Ten years ago - I'd say that 6 month old gas is just fine - not so today... Gas seems to go bad quite fast today. One good thing about C4's is that it's quite easy to get the gas out of the tank - you can try to drain the tank - put in 5 gallons of fresh stuff and see if that helps, but if the fuel filter got clogged up - no amount of fresh stuff will help (but that should show up in the running fuel pressure reading).

As far as the Ignition goes - on a NA motor it seems like the highest spark voltage requirements are low RPM Wide Open Throttle. Whenever I've had an Ignition problem - it's seems most acute under those conditions. So - if your plug gap is too large - I'd expect that it would show up at 1,500 - 2,000 RPM and some boost. To me - 0.040 gap doesn't sound scary - even with moderate boost...
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Old Jun 30, 2016 | 10:14 PM
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Default Procharger

Originally Posted by BrianCunningham
Extra fuel needs more spark to ignite

Perhaps sitting so long gummed things up.

Did ProCharger call for larger injectors, or did they just crank the pressure up.
Procharger has a good unit but 10 years ago their customer service "Sucked"
I don't know how it is today.
Back then when I had the car put on a dyno because it kept breaking up, the operator started waving his hands to stop because the car was running so lean!
I called ATI and spoke to the manager and asked about bigger injectors and he insisted I didn't need them.
He said they sold hundreds of these kits and no one had a problem.
I said, ok , give me one of those phone numbers. He said we can't do that! I said tell them to call me collect. Can't do that!
I said, how about I take the whole damn thing off and send it back?
He said "Is there anything else we can help you with?
What a jerk?
Anyway, we installed 30 lb injectors and that solved the problem.
Today, I'm not sure what the problem is.

Last edited by Herb; Jul 1, 2016 at 06:51 AM. Reason: Adding sentence
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Old Jul 1, 2016 | 02:05 PM
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Greg @ BlowerWorks is the guy to talk to about any supercharger on a C4

He just sold me a pulley for mine

He knows his stuff and can get it running right.
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Old Jul 1, 2016 | 02:12 PM
  #6  
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I would consider 10 year old injectors sitting 6 months with ethanol in the fuel a possibility unless fuel pressure to the rail checks out. There could be crap you stirred up on the interstate that got into the fuel filter just installed and plugged that. Peak spark requirement is at peak torque as that is where peak cylinder pressure is. Much to the dismay of most bench racers get some plain Jane plugs Champions are cheap and good for this test. Gap them to 0.025 to 0.030 if it gets a lot better work on ignition system wires ignition amp cap rotor all of it. The 0.040 to 0.060 gaps are for low speed smog and make no more power that can be measured in a 3 pull average. The same with 95% of the wires most any set not rotten make within a couple HP but will grant some stand up better to heat long term. That is the covering not the wire. I spent a whole day dyno testing all the ignition tribal knowledge and 99% is just that tribal knowledge and ad hype. 99% of the off the shelf parts worked within less than 1% of all the super high dollar stuff. Do what you will and flame if you like but saw all with my own eyes and read the printout on a 700 HP SBC mule engine.
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Old Jul 2, 2016 | 12:14 AM
  #7  
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I'm not sure what's going on!
I can't find my fuel pressure gauge.
I'll look some more tomorrow.
The car acts different every time I drive it.
If you were watching me leave my house you would have thought I was learning how to drive a stick shift.
The car was bucking down the street and then took off!
It's really a bummer because when it doesn't run right it ruins my attitude.
I did the jumper bit and read the codes on the speedo.

I had a 15,23 and a 34.
15 is a cooler sensor low
23 is a IAT low
And according to the chart the 93 doesn't have a 34 code?
The only thing I did different when I put the car back together was eliminate the EGR system
With block off plates and by passed the coolant to the throttle body.
What's strange is I should of had a code for the EGR!
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Old Jul 3, 2016 | 02:27 AM
  #8  
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Still can't find the fuel pressure gauge so I did an ohms check on the fuel injectors.
It showed 15 to 15.2 on all 8 injectors.
I read somewhere on this forum that it should be 16 + or -5
Mine were a little low. Not sure if that's a problem or not.

Last edited by Herb; Jul 3, 2016 at 02:28 AM. Reason: Grammer
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Old Jul 7, 2016 | 07:59 PM
  #9  
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Default Problem Found!!!!

Originally Posted by Herb
Still can't find the fuel pressure gauge so I did an ohms check on the fuel injectors.
It showed 15 to 15.2 on all 8 injectors.
I read somewhere on this forum that it should be 16 + or -5
Mine were a little low. Not sure if that's a problem or not.
The BadMobile is back in the game.

New shooter coming out!

I can't believe how my demeanor has changed now that it's running like it
should.

I ordered a new connector for the IAT and decided to put it on and that was the culprit.

I feel like a new father after a nine month wait!

Cigars for everyone! Thank god!! I can get out of the heat!
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Old Jul 9, 2016 | 04:28 AM
  #10  
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Default

Originally Posted by Herb
The BadMobile is back in the game.

New shooter coming out!

I can't believe how my demeanor has changed now that it's running like it
should.

I ordered a new connector for the IAT and decided to put it on and that was the culprit.

I feel like a new father after a nine month wait!

Cigars for everyone! Thank god!! I can get out of the heat!
Reply

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