Cranks but wont run please help!!

[seanboxster]

I have searched a bunch of places on this Forum and others and have found similar stories but no concrete solution for me yet. I will start with the story of what happened and then what i have done so far also what i think i should do next. thanks for reading!

My car is a 1998 2.5L 5speed.

it cranks and sputters dies immediately. The back story is this...
Was in good running order (apart from check engine light for O2 sensors). was headed home stopped and got gas at a unfamiliar station. Had a short ride home where it sat for a few days then I took her out and within 1 mile it lost a lot of power. It happened right after a hard u-turn and hard acceleration. I limped it into a parking lot and check codes. There were miss fires from almost every cylinder. It would run but just barely probably only a few cylinders firering After moving it to line up for the tow truck it quickly got worse then wouldn't start. I should mention there was and is no smoke or oil loss.

At this point thought well I must have gotten bad gas. So I pulled about 3 gallons of fuel from the tank trough the pump. It looks perfectly clear and smells normal. I realized I never heard the fuel pump come on and prime when trying to start it. So I bypassed the relay , and them pump came on. I replaced the relay but still don't hear it when trying to start.

what i have done:

1.Pulled battery reset Computers and also put it on charger to test (it was and is
good)
2. replace both forward O2 sensors. (already had them on hand to clear a CEL)
3. bypassed Fuel pump relay to confirm the pump is working
4. Replaced Fuel pump relay
5. pumped and examined 3 gallons of fuel from the tank and it seems fine.
6. Observed the RPM Gauge reading upon start attempt( i have read this is a way to
confirm the crank position sensor is reading) Skeptical of this and would like to test
it, thoughts?
7. Also 6 months and 500mls ago i also put new spark plugs, Seals on plug tubes. oil change and filters.

what i am considering doing:
1. Replace fuel filter and clean injectors.
2. Further test Crank position sensor.
3. Replace DME Relay....but where is it? i know its in the trunk but which one? Is it
the same as the starter Relay? (i found a lot of confusing info online about this and
its location.)
4. Change Mass air Flow sensor. ( because i have a spare and why not)
5. Pull oil filter to examine for metal. (not sure if this makes sense.)

Any help is greatly appreciated! sorry for the long write up!

here are the codes at initial break down:
P0300, P0306, P0304, P0305, P1319, P1318, P1316, P1317, P1117.

[Starter986]

Welcome to the forum.

[seanboxster]

Originally Posted by Starter986

Welcome to the forum.

thank you! ive been here a while just lurking in the shadows lol. its the first time Ive felt like i needed to post, there's so much good info already on these forums i usually find my answer.

[Starter986]

In my humble opinion... you have two choices:

1. Continue throwing money at "it" until you hit the jackpot.

2. Pay a few bucks to properly have it diagnosed, and then repair it... or have it repaired.

Best wishes on a quick and relatievly inexpensive outcome (Read: Option 2).

[Nine8Six]

If you don't have access to a Porsche Piwis Tester to carry out the tests than that might actually take quite a while to diag manually. If you have time and basic test tools (DMM, pressure gauges, etc) then google "Boxster Technical Manuals", download those PDFs & follow as many of the diagnostic procedures as you can, you could get lucky.

PS. Careful with open fuel lines, have an emergency plan ready and in reach.

Originally Posted by Starter986

2. Pay a few bucks to properly have it diagnosed, and then repair it... or have it repaired.

^ +1

[thstone]

P0300 - Engine misfire
P0304 - Cyl 4 misfire
P0305 - Cyl 5 misfire
P0306 - Cyl 6 misfire

P1316 Misfire, Cylinder 4, Emission Relevant
P1317 Misfire, Cylinder 5, Emission Relevant
P1318 Misfire, Cylinder 6, Emission Relevant
P1319 Misfire, Emission Relevant

P1117 Oxygen Sensor Heating 1 After Catalytic Converter - Below Lower Limit


I would start cheap and easy:

- Swap the forward O2 sensors (each to the other side) to see if the problem on Bank 2 (cyls 4,5,6 on drivers side) moves with the sensor to Bank 1. If so, then you have a bad forward O2 sensor.
- Replace the MAF
- Inspect for an air leak - focus especially at the hoses and intake components on Bank 2

[Blue99]

Hi. Get a fuel pressure gauge connect it to the valve on the fuel line and check pressure
Just because fuel is pumping does not mean it has pressure the injectors need a min pressure to function don’t throw money at it start at the basics.

[Tremonte986]

Like said above, check the O2 sensor and definitely look for any vacuum leaks or a failed AOS or hose. There is a good chance you may have puked some oil from the AOS into the intake on that hard U-Turn which was ingested on bank 2 and fouled that side. Pull your throttle body and look for excessive oil and recheck the coil packs and plugs. A failed scavenge pump can cause those same codes, but that's bad... really bad and will be evident if you check the timing marks and they are off or pull the sump and find pieces of the drive gear. Eliminate the simple stuff first before throwing parts at her. Fuel? Spark? Air? Go from there.

[seanboxster]

Thanks everyone for the input!

The O2 sensors on bank 1 and 2 are new. I had previously purchased them to resolve a check engine light that I had, I just never got around to doing it. I did finally installed them, just after the breakdown . And they are oem Bosch.

I am trying to not throw money at it, because I don't have money to throw lol.

I will swap the MAF because I have a spare.also I'll check for oil in throttle body and for vacuum leaks. I'll have to rent a fuel gauge but I will work on checking my fuel pressure too.

A long list but atleast these things won't cost my anything. Hopefully it gives up some answers!

[mikefocke]

Pull a spark plug and sniff for fuel. Helps to narrow your focus.

[blue62]

Originally Posted by seanboxster

Thanks everyone for the input!

The O2 sensors on bank 1 and 2 are new. I had previously purchased them to resolve a check engine light that I had, I just never got around to doing it. I did finally installed them, just after the breakdown . And they are oem Bosch.

I am trying to not throw money at it, because I don't have money to throw lol.

I will swap the MAF because I have a spare.also I'll check for oil in throttle body and for vacuum leaks. I'll have to rent a fuel gauge but I will work on checking my fuel pressure too.

A long list but atleast these things won't cost my anything. Hopefully it gives up some answers!

I would not change parts(MAF-O2 sensors) or remove things that are not known problems until I had fixed the no start problem. You can create issues that were not there in the first place and end up just chasing your tail.
You need to start with some basic, simple tests to narrow down the problem.
As to your no start problem-- If you can get a helper, take your air intake at the throttle body off. Get a clean spray bottle put a little gas in it.
Now have the helper crank the engine while you hold the throttle open and spray some fuel into the intake. If the engine fires off you know it is a fuel delivery problem.

You can use starting fluid in place of the spray bottle of gas but personally I prefer the gas.
This is an easy, simple, cheap test, that will give you some good info, a solid starting point and what direction to proceed.
Let us know how you go

[seanboxster]

Originally Posted by blue62

I would not change parts(MAF-O2 sensors) or remove things that are not known problems until I had fixed the no start problem. You can create issues that were not there in the first place and end up just chasing your tail.
You need to start with some basic, simple tests to narrow down the problem.
As to your no start problem-- If you can get a helper, take your air intake at the throttle body off. Get a clean spray bottle put a little gas in it.
Now have the helper crank the engine while you hold the throttle open and spray some fuel into the intake. If the engine fires off you know it is a fuel delivery problem.

You can use starting fluid in place of the spray bottle of gas but personally I prefer the gas.
This is an easy, simple, cheap test, that will give you some good info, a solid starting point and what direction to proceed.
Let us know how you go

That's a great idea thank you.

At this point though I'm afraid that I'm running in circles to avoid the answer of a fried computer or wire harness etc.

[blue62]

Originally Posted by seanboxster

That's a great idea thank you.

At this point though I'm afraid that I'm running in circles to avoid the answer of a fried computer or wire harness etc.

Well I am trying to guide you down a logical path and keep you from running in circles
Try the test I outlined (spraying gas into the intake while cranking the engine).
Let me know the results. Then I will have an idea of which test to do next and which direction to guide you.
Most mechanical issues are relatively simple. But one needs to diagnose them in as logical and linear a fashion as his knowledge and ability allow.
Go from the simplest to the most complex step by step.
So with that in mind and with the test I outlined. I am attempting to determine if you have a fuel delivery issue or an ignition issue.
Once that is determined it gives us a linear direction to go.

[Nine8Six]

Originally Posted by seanboxster

...a fried computer or wire harness etc.

I'd find this hard to believe, it sends back a whole bunch of DTCs, and cranks. All that computer & harness stuff looks perfectly fine to me.
As Blue62 rightly said, its all down to finding whether you have a fuel delivery or an ignition issue at this point. Good luck

[AZ986S]

Originally Posted by Blue99

Hi. Get a fuel pressure gauge connect it to the valve on the fuel line and check pressure
Just because fuel is pumping does not mean it has pressure the injectors need a min pressure to function don’t throw money at it start at the basics.

+1

Check fuel pressure 1rst

[seanboxster]

I got it!!!

So I went to do the suggested fuel test via spraying fuel into the throttle body.
So I removed the intake and before spraying gave it a crank and was suprised by it trying to run. I though this very odd and realized the only thing that would have changed is there being no airflow over the MAF sensor
So I put the intake back and it would not start as previously. So I disconnected the MAF and it ran!!! As it was ideling I plugged the MAF back in and it died immediately. So I swapped it with my spare MAF and good as new. Never in all my no start research or previous research on MAF sensors have I heard of it causing a no start situation.

[blue62]

Originally Posted by seanboxster

I got it!!!

So I went to do the suggested fuel test via spraying fuel into the throttle body.
So I removed the intake and before spraying gave it a crank and was suprised by it trying to run. I though this very odd and realized the only thing that would have changed is there being no airflow over the MAF sensor
So I put the intake back and it would not start as previously. So I disconnected the MAF and it ran!!! As it was ideling I plugged the MAF back in and it died immediately. So I swapped it with my spare MAF and good as new. Never in all my no start research or previous research on MAF sensors have I heard of it causing a no start situation.

I am going to guess that your MAF sensor is the hot film type versus the hot wire type in my 2000S.
I once replaced the hot film type on a Ford pickup. I had rotated it 180 in its mount.
causing it to be mounted upside down. Truck would start but die after about 10 seconds.
Pulled it out and remounted it everything was fine.

Glad you found your problem and that it was an easy fix.
Like I stated in my previous post most mechanical issues are relatively simple issues.
We just need to be methodical and linear in our diagnosis and testing. Makes correcting issues easier and keeps us from chasing our tails

[seanboxster]

So I went to do the suggested spray fuel into the throttle body, and when I removed the intake and was ready to spray I started once with no spray and was suprised when it tried to run! So very confused I started thinking about what changed, the MAF no longer has air passing over it. And or maybe I freed up a clogged intakd. So I inspected the entire intake system and with no blocks I put the intake back on. And again it would not start so I unplugged the MAF and it started and ran! As it was running I plugged it back in and I died. So I replaced it with my spare and good as new!

In all my no start research and previous MAF research have I heard of a bad MAF causing a not start condition. Anyway I'm so happy she's back and running thanks for yalls help!

[seningen]

Originally Posted by blue62

I am going to guess that your MAF sensor is the hot film type versus the hot wire type in my 2000S.
I once replaced the hot film type on a Ford pickup. I had rotated it 180 in its mount.
causing it to be mounted upside down. Truck would start but die after about 10 seconds.
Pulled it out and remounted it everything was fine.

Glad you found your problem and that it was an easy fix.
Like I stated in my previous post most mechanical issues are relatively simple issues.
We just need to be methodical and linear in our diagnosis and testing. Makes correcting issues easier and keeps us from chasing our tails

Nice find --

Mike