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hard start

1266 Views 6 Replies 5 Participants Last post by  steveo
I have a 95 camaro with a 93 LT1 that wont start until the 3rd or 4th crank. Fuel pressure is good, fuel pressure regulator, injectors, fuel pump all functioning well (trust me on that - all new delco parts). Engine coolant temp sensor is good. I accidentally discovered that the car will start (turn right over) when the break booster line is disconnected from the break booster. Why and I know I'm on to a solution but need help. Thank you, Dan
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Since disconnecting the brake booster line allows unmetered air to enter engine, I would say you have an over rich mixture at start up. The extra air being sucked into the engine is returning the mixture to a usable air/fuel ratio.
that was a perfectly answered question, legit answer coco :cheers:
Coco that was awesome! Good one!
that makes sense. So what do I do to create the right ratio without having to remove the line lol. I cant find anyone in Houston to tune in since its too old here in Houston. Would that be something that I would want to get my own tuner software and hardware for. Can anyone reccommend a place/company or any other ideas. Ideas of how to adjust the mixture that the pcm does not seem to be accomplishing?
Before you go looking for a tuner, put your car on an obd1 scanner capable of showing real time sensor data. If you don't have such a scanner, you can download a free obd1 scan program made for 94 & 95 f-bodies. It's in the 4th gen section. You will, however, need a laptop or notebook and a cable to connect car's dlc to usb port. Get cable at ALDL OBD1 OBD cable OBDI OBD2 engine codes get the 16 pin model.
Other scan program options are freescan, if you want it pm me with your e-mail address and I'll send it to you.

Or you can download the trial version of DataMaster good for 20 free data scans and unlimited data playback. It's a good program because you can playback the data you recorded in real time, as many times as needed. Get at TunerCat

Also if you need it, I can send you "scanner readings and what they mean".

A tune would not be needed unless you have modified the car, such as cam, headers, etc.
Engine coolant temp sensor is good.
did you test the sensor in the waterpump or the sensor in the cyl head? the one in the waterpump is the only one that matters

a car with a stuck IAC motor will often start with a vacuum line unplugged

just some ideas
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