yet another dumb maf ? or maybe not(long) - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

tahoewrench · 06-04-2005, 05:00 PM

to begin with i purchased this car not running, it had very few problems when it was brought to the shop i purchased it at. i was told it was running rich and then while it was there being diag'd the starter went bad. it turned out to be injectors and o-rings filled the engine with fuel and hydrolocked the engine ceasing the starter. so after replacing those it seems to run great. Except for this strange bogging problem. it seems as though under light to medium throttle the car runs great except for a few very minor stumbles as it climbs rpm's. but then at wide open throttle it seems to stumble a little stronger and then as it gets to about 4800-5000 it's like the computer completley retards or turns off the ignition until it gets back down to around 4000 then it climbs back up again, then stops climbing till it drops to 4k and back up agian. I thought it may be fuel starvation since i noticed when it was real hot it pinged a little. so i replaced the fuel pump, fuel filter, 02 sensor, plugs, wires, cap, rotor, air filter, oil and filter. still does the bog thing, no more ping. i disconnected the tps and it hardly runs, then disconected the maf and it dies immediately. i'm pretty sure its the maf sensor but i was hoping to get someone to confirm these are maf related problems.

p.s. is everyone elses s13 dohc cars as slow as mine I mean, damn, it's like a non vtec civic or something

theicecreamdan · 06-04-2005, 06:35 PM

it would take a LOT of fuel to hydrolock an engine? and that would seize a starter?

get a multi-meter and FSM and check the MAFS before you replace it, its better to end up with those tools and find out for sure if you need the MAFS before you blow the money on that and find out that it isnt the problem.

tahoewrench · 06-05-2005, 10:42 AM

it did take like half a tank to fill my engine past the level of the top of the dipstick. and when the "mechanic" that had it was trying to "fix" it he cranked it and instead of bending valves or breaking rods he just cracked the starter mounts and that's why i had to replace the starter. luckily it just broke the starter and not internals. so on to my problem. i have gone into diag mode and i have no codes. and i checked everything the fsm says to check with the mafs except what i need the consult for. i am starting to wonder if the guy that replaced the fuel pressure regulater put the wrong one in. because it really feels like a fuel starvation problem except how it does this in such a repeatable fashion.

c-los13 · 04-02-2010, 05:03 PM

fuel pump
have the same problem, im getting one myself too

c-los13 · 04-02-2010, 05:04 PM

sorry i just saw you already did that....bump
check the wires that go to the MAF, check the ground in those wires, might be torn or something

06-04-2005, 05:00 PM	#1
tahoewrench Join Date: May 2005 Location: lake tahoe,CA Posts: 13 Trader Rating: (0) Feedback Score: 0 reviews	yet another dumb maf ? or maybe not(long) to begin with i purchased this car not running, it had very few problems when it was brought to the shop i purchased it at. i was told it was running rich and then while it was there being diag'd the starter went bad. it turned out to be injectors and o-rings filled the engine with fuel and hydrolocked the engine ceasing the starter. so after replacing those it seems to run great. Except for this strange bogging problem. it seems as though under light to medium throttle the car runs great except for a few very minor stumbles as it climbs rpm's. but then at wide open throttle it seems to stumble a little stronger and then as it gets to about 4800-5000 it's like the computer completley retards or turns off the ignition until it gets back down to around 4000 then it climbs back up again, then stops climbing till it drops to 4k and back up agian. I thought it may be fuel starvation since i noticed when it was real hot it pinged a little. so i replaced the fuel pump, fuel filter, 02 sensor, plugs, wires, cap, rotor, air filter, oil and filter. still does the bog thing, no more ping. i disconnected the tps and it hardly runs, then disconected the maf and it dies immediately. i'm pretty sure its the maf sensor but i was hoping to get someone to confirm these are maf related problems. p.s. is everyone elses s13 dohc cars as slow as mine I mean, damn, it's like a non vtec civic or something

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06-05-2005, 10:42 AM	#3
tahoewrench Join Date: May 2005 Location: lake tahoe,CA Posts: 13 Trader Rating: (0) Feedback Score: 0 reviews	it did take like half a tank to fill my engine past the level of the top of the dipstick. and when the "mechanic" that had it was trying to "fix" it he cranked it and instead of bending valves or breaking rods he just cracked the starter mounts and that's why i had to replace the starter. luckily it just broke the starter and not internals. so on to my problem. i have gone into diag mode and i have no codes. and i checked everything the fsm says to check with the mafs except what i need the consult for. i am starting to wonder if the guy that replaced the fuel pressure regulater put the wrong one in. because it really feels like a fuel starvation problem except how it does this in such a repeatable fashion.

04-02-2010, 05:03 PM	#4
c-los13 Zilvia Junkie Join Date: Feb 2010 Location: Edinburg, Texas Age: 36 Posts: 446 Trader Rating: (0) Feedback Score: 0 reviews	fuel pump have the same problem, im getting one myself too

04-02-2010, 05:04 PM	#5
c-los13 Zilvia Junkie Join Date: Feb 2010 Location: Edinburg, Texas Age: 36 Posts: 446 Trader Rating: (0) Feedback Score: 0 reviews	sorry i just saw you already did that....bump check the wires that go to the MAF, check the ground in those wires, might be torn or something