any auto techs? having odd issue!

R

resurrected89

Member
May 4, 2012
29
1
34
middle of new york
I have a 95 Saturn sl2 that's modded pretty good. I fired ot up yesterday and it ran about a minute and started idle hunting. Then my afr went off the gauge LEAN! Car warms up to about quarter on temp gauge and idle smooths out. I tryed changing iat and tps. The coolant sensors are new as well. I blocked off egr but it mad no difference. I have no check engine light. Poked around with my snap on computer and came up with nothing other then it also said lean for fuel trim . Lost here not sure what it could be. Not sure if any one here can help but figured its worth a shot.

List of mods:
2000 block with tie plate
98 crank
Crower rods
Cp pistons
98 ported head
Sda cams
Sda valves
Ported intake
Saturn motorsport big bore throttle body ( taper bore as well)
Cold air intake
3 to 2 header with 2 to 1 down pipe
2.5" header back with magnaflow high flow cat and Jones resonator
 
vacuum leak ?
have you thrown a vacuum gauge on it ?

fuel pressure ?
 
I'm going to toss fuel pressure gauge on it tomaro. I doubt that will tell me much its a return fuel system it runs wfo and sends what's left back. There isn't much on it for vacuum. Checked what was there no problems. I mite make a build thread for it . Cars really fun to drive but its not up to par weather's turning around and I wana roll it out soon.
 
Sure did it was running ok when I put it in the garage 4 months ago. I run it here and there too. Fired it up other day and this happened. The hunting deal happened before though lean is new. It's frustrating have lot of time and money into it.
 
I'm also one to say...check fuel pressure! Even though your system has a return line, it should still pump up and hold pressure when the key is turned on. Unless you are running an aftermarket fuel pump and/or pressure regulator on your built engine, you'll need it to hold between 40-60 psi when the pump is switched on. An aftermarket pump may put out more pressure. In this case, check the spec for your pump. Whatever system you are using, though, if the pressure fails to build, or if it leaks down over the course of several minutes, you have a problem with an injector (not likely...you'd be rich then), the regulator, or the fuel pump itself.

Assuming the fuel pressure tests good, (and even if it is weak come to think of it) how is your fuel filter? When was the last time you changed it? If in doubt...change it out with a fresh one and re-check the fuel pressure.

A lot of the symptoms you are seeing could have been caused by sitting, especially if there wasn't much fuel left in the tank when the car was put up. Ethanol in today's gas causes alll sorts of problems, and modern gas can go bad in as few as 20 days. It is possible your fuel pump and/or filter has gummed-up from sitting.
 
All ready changed the iac didn't change anything. My computer doesn't have the scope its kinda old but works really well. I can get my hands on a newer snap on. I may have another 02 sensor to swap and try. I will check the fuel pressure for sure. The filter is about 2 years old maybe just change it out. I ONLY RUN 91 NON ETHANOL IN IT! Local gas chain sells non ethanol so that's where I go for my quads and this car.
 
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