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-   -   Bizarre Tuning Problems (https://www.nopistons.com/2nd-generation-specific-17/bizarre-tuning-problems-31883/)

JLB 01-14-2004 10:40 PM

Well, still trying to track down all the issues from when I went back to the stock fuel injection on my '91. I did some pretty good sized street porting on the engine, removed the 5/6 port sleeves (and pressed some inserts similar to Pineapples directly into the housings), and disabled the VDI. I had not used the stock fuel injection for several years, and never on a ported engine.



The car starts perfectly when cold; when warm sometimes has to turn over about 4 seconds without firing before suddenly starting like normal. Before it is completely warmed up the car pulls strong and smoothly right up to redline. Once it has been running a good while it looses some power.



If I set the timing by the marks it won't start at all. To get the best starting, idle, and midrange I have the timing about 15 degrees advanced from the mark. To get strong top end (right to 8600!) I have to turn the distributor another 10 degrees. It's like the advance curve is not right...



Even with it advanced, at 7000 there is a huge stumble, then it pulls strong again to fuel cut.



What could be causing all of this? With the TPS set with the 2 led setup I still have an idle that hunts bad from about 800 - 1600rpms.



I'm starting to wonder about the water temp sensor - but haven't bothered to pull the alt off and check it yet. Any other suggestions??



Thanks!

Jason

1Revvin7 01-14-2004 10:43 PM

Pull codes?

JLB 01-15-2004 08:31 AM

Through all of this I have not had a check engine light. But I will pull the codes in a bit and see what's there. Since I have removed ALL the emissions stuff there is going to be a ton of solenoid codes...



Jason

JLB 01-15-2004 09:10 AM

Just checked the codes - nothing but solenoid related ones that were expected since there are no solenoid valves any more...



Codes were 25, 30, 31, 32, 33, 38, 40, 41, 45



Jason

j9fd3s 01-15-2004 10:55 AM

you might wanna put resistors in there so it thinks that everything is there (esp the fuel pressure regulator)



remember



happy ecu = happy you

bebesito21 01-16-2004 03:39 PM

damn, im having a hesitation too between 5 and 6k and my engine is the same as his except mine is bridgeported not streetported. My timing is fine though. Anyone have thought as to what it can be. Its like a few stutters and then it goes clean to 8500.

JLB 01-16-2004 05:00 PM

Do you have the orfice pill in your boost sensor hose? Before I went turbo and then ported the engine mine was extremely sensitive to not having an orfice installed... A .020 - .030 hole dampens out the pulses to the sensor.


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