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Old 09-23-2008   #1
Jarek5_7
 
Join Date: Aug 2008
Location: Radom, Poland
Posts: 38
Default full power doesnt work

hello again

I was writing some time ago about some efi problems of my vette.
for those who are interested here is the pic of my c4. its a c4 convertible with zr1 engine, trans and interior, exhaust etc.

I bought it cheap and now I`m putting a second life into her, or I`m trying as for now

I replaced spark plugs, wires, coils, injectors from FIC ( great stuff and customer service), map sensor, I put new gaskets beetween TB, and new for plenum, I`ve checked fuel pumps, they`re ok.

before that the car barely drove. now it drives good in normal power mode, but full power isnt working ok. on full power it hesitates, has no diffrence in power and have very high idle. first thing to come into my mind is the secondary vacuum solenoid, I thing its bad, I checked it when had plenum off but I did put all the things toghether , just couldnt wait to see if new coils and injectors help a little.

so I think the secondary throttles stay open too long causing high idle and bad air/fuel mixtures on full throttle.

other thing is that tach reads bad, it show too high rpm that they are in real, for example tach shows 4000rpm, but on my looks they are 2k-2,5k what can cause it?

I will connect the car to scanner and hope it will get me on track with this.

I`ve tried to read codes with paper clip but how long should it take to show code 12? I put clip on AB pins, put key o ign on, fan was on but I waited for 12 code on SES light with no luck. Now I think I could wait longer but how long should it take?

here the pic of the car I took today when checking if those wheels will fit.
I will put her on 19x9.5 front and 20x10.5 rear

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Old 09-23-2008   #2
tccrab
 
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Join Date: Oct 2004
Location: Folsom CA
Posts: 1,656
Default Re: full power doesnt work

Since it runs well in regular power mode then all the basic functions of the ECM appear to be working.
Full power mode not working will be either air or fuel.
Too much of either will cause problems, as well as too little.
Try to find out which case, are you too lean or too rich.
Then diagnosing will be much easier.

As far as the electronics not working correctly; the tach being off and the ODB1 plug not working, I have no idea.
Since your car started life as a regular LT1/L98 car and then modified, it could be anywhere or anything. I would not know where to begin.

By the way, it's a BEAUTIFUL car.
I wish it were mine.... ;-)
I'm not usually a big fan of 20" wheels, but yours look OK on your car.

TomC
"Crabs"
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Last edited by tccrab; 09-23-2008 at 02:29 PM.
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Old 09-23-2008   #3
Sgreg
 
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Join Date: Aug 2006
Location: Texas
Posts: 518
Default Re: full power doesnt work

Or it just could be a bad valet or power switch !!!!!!
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