what else can it be?
09-17-2007, 08:24 PM
#1
what else can it be?
Car went on the dyno this past weekend, didnt turn out so good. Once the gentleman put it on the dyno, he couldnt get it to go pas 4500 rpm! It was like he hit a rev limiter or something. On the chart, it has lean spikes at 4500 and was making terrible power....So he put the engine on more load.....made it worse. After he did that, he suggested it was something to do with the ignition. I am not saying it isnt, but it seems so simple....I am replacing the wires and coil anyway (distributor doesnt even have 1k miles on it) and the car was tuned. Anybody think it is something else?
09-17-2007, 09:39 PM
#3
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Re: what else can it be?
When they 'go flat' at the top end, it usually is ignition. Its interesting that you are going lean though. Keep pluggin, you will get it - thats what the dyno is for.
Last edited by rhamm1320; 09-18-2007 at 10:04 PM.
09-17-2007, 09:44 PM
#4
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Car: 91 RS
Engine: 350 vortec
Transmission: T-5
Axle/Gears: not the best not the worst
Re: what else can it be?
i doubt it is ignition as a miss fire would cause rich spikes i believe... i am betting it is fuel IE not enough
09-17-2007, 10:12 PM
#6
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Car: 91 RS
Engine: 350 vortec
Transmission: T-5
Axle/Gears: not the best not the worst
Re: what else can it be?
okay... you have a lean condition... either fuel...Air... or detonation which one do you want
09-18-2007, 01:05 AM
#7
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Car: 83 TA
Engine: goodwrench 350
Transmission: 700r4
Re: what else can it be?
maybe investing in an in car pressure gauge would help ya out. That way you could go make some WOT blasts on the highway and see if your fuel system is keeping up.
If it was ignition crapping out it would show rich from the unburnt fuel.
If it was ignition crapping out it would show rich from the unburnt fuel.
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09-18-2007, 06:46 PM
#9
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Car: 91 RS
Engine: 350 vortec
Transmission: T-5
Axle/Gears: not the best not the worst
Re: what else can it be?
okay how do you know it is rich... at idle? that isnt going to tell you anything about a loaded WOT run on the dyno... especially as the operator told you there were lean spikes... how lean? might want to actually check the FP and FLOW rate before assuming it is good just because you have a walbro 255 and 30lbs injectors
09-21-2007, 11:09 PM
#11
Re: what else can it be?
okay how do you know it is rich... at idle? that isnt going to tell you anything about a loaded WOT run on the dyno... especially as the operator told you there were lean spikes... how lean? might want to actually check the FP and FLOW rate before assuming it is good just because you have a walbro 255 and 30lbs injectors
09-21-2007, 11:48 PM
#12
Re: what else can it be?
interesting..i wouldnt think you'd hit valve float at 4500 rpms... does the dyno have a wideband o2 sensor for the tail pipe? if it smells rich then maybe not enough ignition up top but if the dyno says lean, then i dont know what to tell yah...hopefully it isnt something serious internally
what is the specs on the springs your running? what is the fuel pressure set at?
what is the specs on the springs your running? what is the fuel pressure set at?