Help Required, Please!
Thread Starter
Racer
Joined: Jan 2011
Posts: 292
Likes: 1
From: Edmond OK
Help Required, Please!
I have a 92 corvette from which i just completed extensive mods. I put long tube headers, RT cats, 3" exhaust. I upgraded to the 2nd generation Opti, Custum CAM--224/230 112, ported and polished heads and intake, new valves/springs and roller rockers--1.6, throttle body bypass, 58 mm throtle body, ford racing 30# injectors, Yank 3600 stall. Had the computor chip made by Ed wright--Fast Chips.
Now, here is the problem. Got the car to start, it will idel rough, running lean--to the point unburt fuel was burning out the exhaust. No power on acceleration, back pressure through intake I suspect.
Were should i begin, it runs like the timing is off. Could it be the computor chip, the opti, ICm, what? how do I trobleshoot this?
Now, here is the problem. Got the car to start, it will idel rough, running lean--to the point unburt fuel was burning out the exhaust. No power on acceleration, back pressure through intake I suspect.
Were should i begin, it runs like the timing is off. Could it be the computor chip, the opti, ICm, what? how do I trobleshoot this?
Last edited by FireRescue; May 3, 2011 at 02:49 PM.
Melting Slicks
Joined: Jan 2009
Posts: 3,181
Likes: 286
From: Puyallup Washington
You will need to start with the basics. I would check opti and wiring for a good spark at the correct time, valve clearance, injectors working properly, and be suspicious of a new chip. Basically I would recheck everything I did except I do not think the exhaust system, if installed properly, would cause the problem or work to the tranny. Unless, of course, wires were pinched. Also check to make sure that all connectors and hoses have been properly reattached.
Race Director
Joined: Nov 2003
Posts: 12,221
Likes: 446
From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
I agree -- if you didn't change injector size.
FireRescue: Did it ever run decent? Did you run it w/o Ed's chip? It's possible to melt cats (yes Random Techs) if the mixture is overly rich. (Rich is where unburnt fuel comes out the tailpipes -- not lean.)
If you melted the cats, your exhaust could be stopped up.
FireRescue: Did it ever run decent? Did you run it w/o Ed's chip? It's possible to melt cats (yes Random Techs) if the mixture is overly rich. (Rich is where unburnt fuel comes out the tailpipes -- not lean.)
If you melted the cats, your exhaust could be stopped up.
Thread Starter
Racer
Joined: Jan 2011
Posts: 292
Likes: 1
From: Edmond OK
How
Is it possible I am off on the top dead center and cam install? Or is the opti just in wrong. It was hard to keep it from spinning when installing.
Last edited by FireRescue; May 3, 2011 at 02:11 PM.
Thread Starter
Racer
Joined: Jan 2011
Posts: 292
Likes: 1
From: Edmond OK
No it never ran correctly. I am going to put the old chip back in and try it. I was told that the car should run correctly with the exception it will run slow and idle low. All the other sysmptoms will go away. If they do then the Chip is not working. Does this sound correct? And I did change the injector size. went with 30#
Last edited by FireRescue; May 3, 2011 at 02:48 PM.
Former Vendor
Joined: Nov 2006
Posts: 2,482
Likes: 3
From: Carmichael ca
If you run the stock chip with 30# injectors its going to run rich. If you do this, don't do it for long. Are you getting any codes? You may have to TDC #1 cylinder and remove the distributer cap
to see if the rotor is pointing at #1.
to see if the rotor is pointing at #1.
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Thread Starter
Racer
Joined: Jan 2011
Posts: 292
Likes: 1
From: Edmond OK
First thanks to all that offer advised. I checked the car over completly. The timing in the motor was set correctly. everything lined up on TDC. I did have loss of compression in number 1. Fixed that problem. Put everthing back together and the car started right up. Drove it for about 10 miles no problems ran perfect. I parked the car. Got up this morning to have the mufflers welded on, car started perfect, got about 5 miles from the house...same problem all over again. loss of power backpressure through intake, difficult to start. Timing again, right? If the computer chip was good, the motor timing was correct, all cylinders have good pressure..what is left? is it possible I have an opti problem. If so why did it run right for a few miles? the only difference this time is I got a code:13. So, I changed the o2 sensors and replaced the alternator. did not fix. any sugestions
Racer
Joined: Jul 2000
Posts: 345
Likes: 2
From: Arlington Wa
The temp sensor located on the water pump can cause it to run rich. I would check it. A $15.00 part caused me some serious headaches, the last thing I would have ever suspected causing the problem I had with mine.