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@lnengineering I considered replacing the injectors during the rebuild, but last summer the injectors for the 3.4 were $240 each. Luckily, it looks like they've come down from that astronomical price to a merely exorbitant $95 each. MAF looks pretty inexpensive and easy to DIY. I'll probably go ahead and do that next weekend. Which would you consider to be the primary O2 sensors - the ones pre or post catalytic converter?
@jumpy chunky Thanks for the detailed info. My charts aren't pretty because I dumped the data into Excel and didn't spend much time on formatting. I should have left RPM out and taken shorter time window. In any case, I'm not looking to spend Durametric money on a scanner, but I wonder if I can back into the RKAT values from other readings? I can definitely get the MAF and O2 sensor numbers from my current setup and will compare those against the values you suggested.
Just a bit of info on injectors , currently got my engine out and injectors is one of my while your in there jobs!! I have a 99 C2 and the original style injectors are an older design and quite expensive , I was steered into some 3.6 injectors by someone on rennlist for sale on autodoc , original Bosch and like £25 each or something insanely cheap so I ordered them , they came in original Bosch boxes with the Q scan codes on them for authenticity and everything , there's a slight Mod you need to do though as the old injector has two grooves at the top , the top one being for the injector securing clip to connect it on the rail, the new injectors don't have this so you have to carefully cut one into the plastic, I did one yesterday and it worked ok, I could start a thread showing this mod if there's any interest, for me it seems a good way to get one of the bog worry's out the way on the older cars without spending a fortune , you hear so much now about bad injectors and fuel trims etc probably being the underlying cause for failures it's worth the price of mind and although easier with engine out is a job that can be done with the engine still in the car!
Just a bit of info on injectors , currently got my engine out and injectors is one of my while your in there jobs!! I have a 99 C2 and the original style injectors are an older design and quite expensive , I was steered into some 3.6 injectors by someone on rennlist for sale on autodoc , original Bosch and like £25 each or something insanely cheap so I ordered them , they came in original Bosch boxes with the Q scan codes on them for authenticity and everything , there's a slight Mod you need to do though as the old injector has two grooves at the top , the top one being for the injector securing clip to connect it on the rail, the new injectors don't have this so you have to carefully cut one into the plastic, I did one yesterday and it worked ok, I could start a thread showing this mod if there's any interest, for me it seems a good way to get one of the bog worry's out the way on the older cars without spending a fortune , you hear so much now about bad injectors and fuel trims etc probably being the underlying cause for failures it's worth the price of mind and although easier with engine out is a job that can be done with the engine still in the car!
Yes, please. I know I've seen this mentioned previously. Did not note that significant details were provided.
As stated, 3.6 injectors will work with 3.4 fuel rail. I purchased from https://www.germanautosupply.com/cat...-Fuel.Injector . They arrived with Bosch package security tape, and a way to validate the code on Bosche's website. You'll need to cut another groove in the 3.6 injectors. I used a "micro" dremel, with a cutting tip about the size of a sharpened pencil. Here's a link to a photo: left to right (all Bosch injectors):
LEFT: 3.6 (link above)
MIDDLE: aftermarket for VF Engineering Supercharger
RIGHT: original 3.4 3 Fuel Injectors for the M96
Your MAF value is higher than it should be for a
3.4. Shouldn't deviate more than 1 or 2 KG.
You may want to measure again or clean or replace MAF. Your O2 sensor value shows a lean condition.
Thanks for the details on the sensor values.
Originally Posted by 808Bill
Considering the cost of a rebuild vs the savings on new injectors is small money, Protect your investment!
Since the cost of the rebuild is so high, everything else seems small by comparison. All these little "insurance" items can add up. Charles' recommendation is $800 in parts, plus I'll need to pay my mechanic to replace the injectors - not a job I'm confident doing myself. $1k here, $1k there, and soon we're talking about real money
Originally Posted by yelcab
I did not read your other thread so I cannot tell why you want to do this. Is there a running issue? Is there a CEL code? Is there a hot glowing Cat? What leads to this point?
I have a new short block with refinished heads and a bunch of other new parts including AOS and coolant tank. I don't have any CELs or problems with the engine (except it seems to idle a little low at times). This journey was sparked by the fact that my last block died of bore scoring, and Charles and others have pointed out that the fuel system could have contributed to that. I want to make sure it doesn't happen again.
Originally Posted by jllphan
The injectors you linked are designed for the 3.6, OP has the 3.4. While it is possible to use the 3.6 injectors, some modification is necessary, just a heads up.
FYI - All you Mk2 owners may not realize that a few of the Mk1 parts are way more expensive than what you spend on your cars. Coolant tank is $600 (vs $200) and injectors are $95 ea (vs $35). Last year the best deal on genuine or Bosch injectors was over $200.
It looks like FCP Euro has a close out on Bosch MAF sensors for $120. I may get that and the O2 Sensors as something I can do at home that isn't too big of an investment. Bosch O2 sensors are $50 each.
Ordered the sensors. We’ll see how long they take to arrive under the current circumstances.
I also find this post on O2 sensors that I found very informative. It’s Boxster-centric and the parts info is a bit out of date, but I thought the description of how the sensors work in the first section was very helpful for understanding what’s happening. https://sites.google.com/site/mikefocke2/oxygensensors
I get it, I couldn't afford to have someone else do all my work, so I have to learn, but...If I can do it, anyone can!
I’m learning and taking care of the stuff I can. I did my own brakes, fixed the sunroof, and plan to do more. My issue is not having enough space and time for more complicated projects.
I’m learning and taking care of the stuff I can. I did my own brakes, fixed the sunroof, and plan to do more. My issue is not having enough space and time for more complicated projects.
Most of us have all the time in the world right now. Glad your still working!
Most of us have all the time in the world right now. Glad your still working!
I count myself as extremely fortunate that I'm still working during the current circumstances and that I can do it safely from home. I know what it's like to be out of of job, so I empathize with everyone out there who can't work right now. That's why I'm glad to be working on a project that helps auto body shops accept payments online, so they can continue to work and maintain a safe social distance.
As nice as it might be to have time for garage projects, I hope you and everyone else on here are back to work ASAP.
I installed the new MAF sensor this afternoon, along with a new air filter. There was no visible gunk on the old sensor, in fact it was hard to tell it apart from the new one.
I let the engine come up to temp and looked at the live readings on my OBD scan app. It looks like my air flow readings are lower now (.6-.7lbs/min or ~17-19kg/hr) and my STFT is bouncing slightly negative to slightly positive, as expected. So maybe there was something off with the MAF sensor?
I still see higher readings for LTFT (+6-8%). In fact they didn’t budge even a .1% over several minutes. Does LTFT only change once you’re driving, or is there potentially a bug with my scanner?
LT, is long term. It takes, as the term might imply, time. More driving and continued monitoring are advised.
Not sure if there is a reset. Maybe the disconnection of the battery and touching the two leads together for twenty(?) seconds will reset the DME. Just going off the cuff on this last one...
LT, is long term. It takes, as the term might imply, time. More driving and continued monitoring are advised.
“Long term” is relative. I’ve read that short term is sampled at less than a second. Long term changes take place in something like 29-30 seconds. Not sure what correct answer is for these engines or if it matters whether you are driving or not.
I installed the new MAF sensor this afternoon, along with a new air filter. There was no visible gunk on the old sensor, in fact it was hard to tell it apart from the new one.
I let the engine come up to temp and looked at the live readings on my OBD scan app. It looks like my air flow readings are lower now (.6-.7lbs/min or ~17-19kg/hr) and my STFT is bouncing slightly negative to slightly positive, as expected. So maybe there was something off with the MAF sensor?
I still see higher readings for LTFT (+6-8%). In fact they didn’t budge even a .1% over several minutes. Does LTFT only change once you’re driving, or is there potentially a bug with my scanner?
Ideally, you need to perform a vehicle handover to "reset" the learned fuel trims. It will adjust, but it will take time to correct itself if you don't do a vehicle handover. I do not think you can do a VH with a Durametric either - that's something you need a PIWIS for.
Ideally, you need to perform a vehicle handover to "reset" the learned fuel trims. It will adjust, but it will take time to correct itself if you don't do a vehicle handover. I do not think you can do a VH with a Durametric either - that's something you need a PIWIS for.
Can you explain this in more detail when you have a chance?
04-20-2020, 02:58 PM
