wpgshark

Long Story.
The 89 was in need of new injectors, 3 leaking and one cracked.

I decided that while upgrading injectors I would add the porken S300 chip.

Bought everything last year, and as the car was running well enough, hard to start when it had been left for 8 hours or more or within the first 30 minutes after shutting it off, and harder to start between the 30 minutes and 8 hours, I decided to put the change off until this spring.

Started it yesterday.

Injector install went fine.

When I opened up the LH and EZ ECUs both already had chips from precision racing. Including a modified programming block.

Anyway reinstalled everything and no joy, The fuel rails had fuel, no fuel injector clicking.

Decided that the best way to get to the bottom of it was to revert to the last operating condition, with only the fuel new fuel injectors and work from there.

Didn't run or fire at that condition.

So during the injector change out I fixed a couple of wires, and I went fishing with a magnet in the V for a washer I dropped.

After a lot of reading, I've likely either damaged the LH or messed up the CPS connector with my fishing, although it was alright last year when I did the top end.

I'm going to check for spark,
Check the injector wires for a short,

My question is how comparable is the 88 LH in the 89? I ask because according to JDS they have different part numbers and I have a know good 88 LH. It would be nice to use it as a diagnostic/ temporary controller.

Thanks

Lance

FredR

Lance

As I am aware most of the LH units are interchangeable in that they will operate whether a S4, GTS or a GT- the differences are subtle rather than spectacular. I dumped a GT LH unit straight into my late S4 when the original LH failed and it ran OK. Not so sure about the 87 model LH.

If in doubt just pop John an e-mail or PM.

Rgds

Fred

wpgshark

Fred,

Thanks, for the confirmation, I suspected as much, but good to get some corroboration.

Lance

jcorenman

The LH is compatible for all years 87-95. The differences are mostly with the diagnostics, not the basic functions. The EZK does have some ignition-map differences between S4, GT and GTS.

This is worrisome. Can you post a pic of the "modified programming block"?

wpgshark

Did the swap and car started, won't idle with the #25 injectors. So that confirms ECU.

Now the dilemma, do I put a set of factory injectors back in, I have a couple I can use to replace the cracked one and some leakers, or do I try the chip upgrade again?

Although might heart and *** say chip, my brain is saying injectors.

Jim,

I may have been wrong on the programming block, looks like the guide pin has been broken off, but I will look at it more closely when I pull it out, which may be latter today, or when I get the ECU back.


Thanks for the help.

Lance

FredR

Lance,

Trust I am not missing anything here but if you are running Ken's chipset correct me if I am wrong but it needs 24lb injectors which i understand you have installed. At the moment you are now trying to run a motor with 24lb injectors in it with a chipset prorammed for 19lb items so it is going to run very [approx 25%] rich on a programme that runs top end rich to start with. It will fire/ run but ....? Starting should be easy so long as you do not wet the plugs.

Now, having established it is running with another computer you are having some hesitation about fitting Ken's chips in because of the earlier problem and presumably you are worried about screwing up a second LH unit- is that about the long and short of it?

Rgds

Fred

PorKen

As always it is best to make sure it runs well before doing any kind of upgrades...but I never listened to this either.

Once in a while the chips go bad in transport, X-rays, lightning, handling, I don't know. (I use CMOS chips {vs. NMOS} for a little less sensitivity to static, but they still go bad.) Double check that the chips are installed the correct way.

Try the ignition or fuel chip by itself with the corresponding stock chip in the other box.

wpgshark

Fred, Ken

Just having the same discussion with my son, the enabler.

Before the change over car was running well, except for the starting problem, which I knew was injectors, based on wet plugs.

https://rennlist.com/forums/928-foru...-infected.html

Car was rebuilt after an engine fire, link above. New plugs wires, distributors, distributor caps, knock sensors, re-calibrated MAF. and vacuum lines, large and small. Car ran really really well once started and I knew why it wasn't starting so good candidate for chip swap with injectors.

Although I suspect that the ECU may already have been weak, I understand a shorted fuel injector wire can take it out, and there was more than one of those during the fire. I may also not have handled it with a require delicateness, I regularly work with controllers and have become less careful with age. I also know that occasionally chips go bad.

So as I was saying to my enabler, I put stock injectors back in get the LH rebuilt and start again with a spare in 3 weeks I'm still driving tomorrow. Although I suspect there will not be a problem with the chip, and if there is it won't ruin another controller, for one thing if it doesn't start immediately the test will be over, whereas first go around we went a long time, if I'm wrong the car is parked for 3 weeks while I get 2 LH units rebuilt.

The enabler says it is worth the risk. He finds the hard start really kills the effect when he takes the car out

wpgshark

Ken,

We have had problems with controllers being scrambled as well when shipped. We started labeling them as sensitive to scanning equipment, hand check only, and the incidence of failure went down to near 0.

Something you might consider.

Lance

John Speake

The fuel maps in all the 87-94 LH ECUs are essentially the same. The car should start OK with any
LH version, even with 24# injectors in place of 19#. Due to cold start and warm up enrichment, injector size differences won't have any real effect between the two sizes until the car is fully warmed up. Even then the O2 loop will try hard to get the fuelling OK.

Try swapping the chip in the EZK first, see if the car has spark, even if it won't fire. If the old chips had some sort of adaptor between the chip socket and the "Precision Racing chip" the remove that before fitting Ken's chips. That applies to both ECU.

wpgshark

OK, If I was a practical sensible individual I wouldn't own 928s. So on with the swap.

First put the old EX back in, started wouldn't run, so that ECU was good.

Put ken's chip into the EZ and went through the same process, same result start no run. Getting really quick at the in and out now.

Put Ken's chip into the LH and same results, the first time, second time it started and ran, although idle was still rough but getting better quickly.

Took it for a quick run, compared to the the precision racing chip.

Held gears longer.
Car was noticeably quieter until 5,000 RPM full throttle.
Car had a lot more torque, applying full throttle at 50 kph, 30 mph, resulted in lots of wheel spin, even without the downshift.
Much better city gas mileage, still early, but normal glances at the instant mileage usually saw 8-9.5 l per 100 km, I think that's around 30 mph, with ken's slowing down to normal I was seeing some stuff in the 7s, which I only saw coasting previously, and in the 4-5 range coasting which I've never seen.

Really happy.

With the new injectors car starts really nice. I took a picture of the programming block, it is different than Ken's as well as the 88. However the 88 is a manual. I'll post a picture when I have tome to upload it to a computer.



I'll get the LH rebuilt and move them all around again, maybe Ken will send me the v1.15 so I can review it as well. Then it will be on to the 88 5-speed.

Thanks all for the help.

Lance

John Speake

Glad to have got the car to run. The long time that was needed to adapt to the chips sounds to me as though the MAF may be badly aged.....

wpgshark

Re calibrated MAF from Roger last year, would have expected it to be your work.
Car is running very well, took it for a quick 180km run, saw fuel economy that I could only dream about, as low as 8.5 l/100 km, 900 km range, that's as good as the TDI I once had.

Very happy.

FredR

You may have changed your chips and injectors and have an optimal fuelling situation but the logic that tells the display how much fuel you have used has not changed and your actual fuel consumed will be somewhere in the range of 24/19 times the number displayed [surprise surprise]. Unless of course Professor Ken managed to alter something in the logic to change this as well?

When you have 30lb injectors [like I have] it gets even more impressive but the number of visits to the gas station do not support the perception- but that is using ST2!

Apologies if I am peeing on your parade here- trust I am on the correct trajectory- apologies if not.

Rgds

Fred

wpgshark

Good point, it was fun while it lasted.

Ken ?????