J30 cutting when floored

[leedrm]

OK, I am running out of options and convince that the dealership is wrong.

1995 j30 128000 miles. Love it. owned for 10 years. I can drive about 65 miles and the engine cuts out, like its flooded. Cant drive over 20miles an hour. No check engine light.

When running good engine idles sometime good sometime like a miss.

Solution 1.changed fuel pump and filter.....Same thing

Soultion 2.got used MAF for 30.00 (tested good) same problem

Solution 3. Got new MAF same problem.

I am thinking either clean fuel injectors or TPS...

one more things...when gas was stupid high, I ran maybe 2 tanks of 89 oct in car....I was thinking of a remote problem could be timing, due to cheap gas...

please help...running out of solutions.

[gr8scott72]

OK, I am running out of options and convince that the dealership is wrong.

1995 j30 128000 miles. Love it. owned for 10 years. I can drive about 65 miles and the engine cuts out, like its flooded. Cant drive over 20miles an hour. No check engine light.

When running good engine idles sometime good sometime like a miss.

Solution 1.changed fuel pump and filter.....Same thing

Soultion 2.got used MAF for 30.00 (tested good) same problem

Solution 3. Got new MAF same problem.

I am thinking either clean fuel injectors or TPS...

one more things...when gas was stupid high, I ran maybe 2 tanks of 89 oct in car....I was thinking of a remote problem could be timing, due to cheap gas...

please help...running out of solutions.

Checked for any codes?

[leedrm]

No codes....Nothing.

[kbflip02]

No codes....Nothing.

possible FPC....check the relay in the fuse box for your fuel pump....also if you did run 89 octane i would run some seafoam....however i am leaning towards the TPS...

[yodawill2000]

Redline S1 in the tank ..Seafoam in the intake .

[gr8scott72]

No codes....Nothing.

No codes stored on the ecu, checked by means of pulling ecu out and looking at blinking light on side? Or no codes meaning no check engine light?

[GerryO]

KS issues will not trigger the CEL light, but will leave a stored code.

A bad injector coil will trigger the CEL, as will failing O2 sensors. Don't know about a physically clogged injector.

Engine cuts out and completely dies or is simply very under-powered? One cylinder that isn't firing will cause a J30 to run poorly, but you can still easily do more than 20 mph.

Transmission codes check? Check vacuum hoses for an intake leak?

What is the dealership saying?

[#1 Sailor Scout]

OK, I am running out of options and convince that the dealership is wrong.

1995 j30 128000 miles. Love it. owned for 10 years. I can drive about 65 miles and the engine cuts out, like its flooded. Cant drive over 20miles an hour. No check engine light.

When running good engine idles sometime good sometime like a miss.

Solution 1.changed fuel pump and filter.....Same thing

Soultion 2.got used MAF for 30.00 (tested good) same problem

Solution 3. Got new MAF same problem.

I am thinking either clean fuel injectors or TPS...

one more things...when gas was stupid high, I ran maybe 2 tanks of 89 oct in car....I was thinking of a remote problem could be timing, due to cheap gas...

please help...running out of solutions.

Finally, another NICO member in Mobile, AL!!!!!! Welcome to NICO!!!!!

I suggest doing what yodawill2000 said. Or you can head to Infiniti of Mobile. Maybe they know something we don't.

[leedrm]

Thanks for all responses...I will ahead and bought a TPS...Ive always been alittle nervous about pulling additives to car. I am going to try sea-foam and also going to get throttle bodies and injectors cleaned..

BTW, the dealership is wrong...they say MAF, but I have replaced and same thing is happening.

Will advise on sea-foam and injectors.

[leedrm]

No codes stored on the ecu, checked by means of pulling ecu out and looking at blinking light on side? Or no codes meaning no check engine light?

no check engine...dealership said no codes...confusing.

[Infinitiguy19]

ITS THE FUEL PUMP CONTROL UNIT OR FUEL PUMP, Your description screams it.

[leedrm]

Brand spanking new fuel pump....I was thinking possibly about fuel sending until, but dealership checked fuel pressure and its fine.

[Infinitiguy19]

They checked the pressure in all fuel pump modes, Idle, Cruise and WOT AKA Wide Open Throttle?

If yes then I think it might be a crankshaft sensor or cam sensor but those a re a reach.

[leedrm]

Sorry for delay in responding.....ok briefing....

Replace TPS....no effect still cutting out.

j30 cuttings out when floored....

I have one final solution, and taking car to dealership and having new TPS adjusted and injector cleaned and checked....

I have thought that it was them most of the time, but the dealership was saying MAF, I have proved not MAF, fuel pump, fuel filter and TPS....

Any other ideas would be greatly apprecicated.

Lee

[Infinitiguy19]

Did you read my last post?

If you take it to the dealer you might as well throw you money out the window.

Trust me I know what I am talking about, If not read the service manual and you will see.

TPS sensor affects shifting and accleration.

MAF sensor Would cause shaking, rough idle, stall upon braking.

Injector cleaning is useless in my opinion because either the injectors are good or too far gone and need replaceing, Because I think the clog would disapear at 34-43 PSI.

Fuel filter would cause fuel depravation if it is in need of replacing, Symtoms would be RPM limit, stalling and slow accleration.

Fuel Pump is usually the cause of all problems on Q45's, But a bad FP would cause rough idle, loud buzzing noise from the trunk and fuel depravation if it takes out the FP controller.

Merry Christmas.

[leedrm]

thanks for response....I notice the other day a very slight smell of gas, i've notice it before but dismissed due the changing of the fuel pump. The garage told me that they spilled while replacing. But that has been months ago, it should be gone by now...And its only time to time, I've never smelled it under the hood.

This weekend I will replace the filter again.

I hate going to the dealership, I just think they are all idiots.

I just thought of something, could it be possible the coil packs?

Thanks for your help...

Have a safe new year.


Modified by leedrm at 9:39 AM 12/31/2008

[Infinitiguy19]

What I recomend doing is filling up the gas tank to nearly full or as much as you can afford, then go and drive crazy in a closed parking lot to see if any of the gas is leaking from the top of the tank.

Why I recomend the above: Well I had some jack *** use bigger screws that punchtured the tank and i was smelling gas all the time, too it to the shop and they said the gas tank was not sealed so the fuel system could never pressurize too. The fix was a new gas tank.

As for fuel smell in the engine bay, How long ago were the under plenum hoses changed?

Was the fuel pump changed at the dealership?

The coil packs would cause drivability problems, idle problems. Basically a bad coil pack would be a bad cylinder or a cylinder that won't produce any power.

Replacing the fuel filter at least every 6 months is great or every year at least.

Happy New Year to you as well, Paul

[leedrm]

Im pretty sure no leak in the tank...

Also I check the coil packs yesterday, nothing wrong with them. I change in idle on everyone.

As far as the fuel pump and fuel filters, they was changed on vacation at a garage in FL. They replace it as well as fuel pump, this all happened in 08-08. They were not the problems.

Things Ive replaced:fuel pump, fuel filter, MAF, TPS & Air filter.

I have been battling this problem for months. The dealership check the fuel pump, they said good pressure...

I have really run out of options...I guess its time for a new car. Ive had my eye on a G35. Maybe its time.

Lee

[GerryO]

65 miles of continuous freeway or stop and go driving?

Coolant or fuel temperature sensor?

Checked the resistance of all six fuel njectors when the engine is warm/exhibiting the problem?

What does the FSM say about warm/hot engine performance related issues?

[swimshark]

have you checked you idle air control valve? my friends 300zxtt kept on goinginto safety boost with no codes and it ended up being his iacv was dirty.

[leedrm]

Now I am down to just a few days before it start acting up....City or highway. Today I drove 6 miles.

[leedrm]

I will look into idle air control valve, will clean and let you know.

Thanks, Lee

[Clyons0203]

My J30 does the exact same thing.

It will idle fun when its cold. It will drive fine when its cold. Engine will rev freely to redline when cold.

But when engine warms up, i sputters so bad the revs wont go over 3000. No cel (havent checked codes yet), no AT light, and no AT codes.

When I drive the car will only do 30-40mph when warm, the CEL will come on then go off, every 15-20 miles. The AT light will also come on and go off.

I just bought a USB consult cable and datascan, when it arrives I am going to monitor all sensors and report back

[Clyons0203]

One think I noticed about the person that started this thread. I noticed you replace the fuel pump, but did you replace the fuel pump control unit? this is the unit that sets the pressure at idle, cruis, and wot.

Most likely the dealership checked the pressure at idle and didnt test WOT or cruise.

[yodawill2000]

sounds like something is throwing the transmission into "Safe Mode"

[Clyons0203]

Can somebody explain to me what is this safe mode?

[yodawill2000]

if the transmission detects a problem it will go into safe mode.The FSM explains it better than I can.FSM is Field Service manual by the way.

[Clyons0203]

I cant find anything about safe mode in the FSM. What page is it on?

[yodawill2000]

Page 17 in the AT section

[Clyons0203]

I still dont see it. Am i missing something?