tcd s1 dialing in and tuning help

[al525i]

Okay, so today was a big day. I finally got to drive my car and overall its good, still a major laundry list of things to fix but its getting there

Here's a brief rundown of my setup:

m30b35 freshly rebuilt
1.3 motronic running a stock 179 ecu from an e32
30lb/hr injectors
begi rising rate fuel pressure regulator
TCD S1 with full 3" exhaust
wideband o2 hooked into a laptop for data logging

Here's what I've got going on currently:

stumbles off idle unless you feather the throttle. pulls smoothly otherwise but you have to get it past the idle/drive threshold carefully

Air/fuel ratio running 14.7:1 at idle goes fatter as it transitions to boost and stays between 10-12:1 under boost.

as boost comes up it pulls smoothly but I got a pretty noticeable spark knock the two times I let it pull past 4k (as soon as I heard it I got off the throttle and babied it. I put a bit more fuel to the RRFPR and tried again but it doesn't seem to be fuel related (not surprising)


I have stock (new, but stock) spark plugs installed and I think that's part of the problem. Suggestions on spark plugs?


secondly, I'm torn between a TCD turbo chip for the 179 ecu and just going ahead and doing megasquirt. Thoughts here??? I'm leaning toward the megasquirt but its a bit daunting.

My plans were to get it sorted with the motronic then go megasquirt after it was properly broken in if it'll run safely on the 179

sorry for the rambling and thanks in advance!

[tschultz]

What boost pressure are you starting at?

Usually it's best to tune in increments until you are sure that the 'kinks' are worked out at 6psi or so.

[al525i]

umm..

its whatever spring is in the wastegate currently.

that is a pretty great question and one that completely slipped my mind to check.

I'll pull it tomorrow and put the 6psi stuff in if its not already

[Rich in Tupelo]

Alex,

The ECU I came with the stuff had the TCD chip in it if you still have that.

[al525i]

Rich,

I do still have that ecu, but I think its an 059 for the early motronic so I don't think the chip is compatable with 1.3 and the 179.

unless I'm wrong and the 059 I have isn't from you. Do you remember what ecu you gave me? I've got so much stuff laying around at this point its sad and with all the moves and things that have happened I don't know 100% what came from where anymore. I seem to have a full m30b34 harness with a fuse box that I have no idea where it came from but the l-jet harness that was on my car last and the ecu seems to be gone

[Rich in Tupelo]

I don't recall if it was a 059 or 179. I know it did have the TCD chip in it, not sure what map was loaded.

[T_C_D]

What is the fuel pressure at idle and atmospheric and 4000rpm? What is the AFR at all those points as well. Did you install an o2 clamp? You know you can call me anytime for tech support 414-265-6004.

[al525i]

I didn't get anything done under the hood today. It is, however fully registered and legal for road use now. I'll get more info for everyone and report back in hopefully tomorrow.

What is the fuel pressure at idle and atmospheric and 4000rpm? What is the AFR at all those points as well. Did you install an o2 clamp? You know you can call me anytime for tech support 414-265-6004.

I'll move the fuel pressure gauge to the input side of the fuel rail (currently between the factory regulator and the begi) and let you know

What do you mean by o2 clamp?

Currently I'm running a new bosch o2 sensor feeding the motronic and the innovate wideband feeding a george graves display and toughbook for datalogging.

I lost the log file from yesterday when the software froze and today I kept it at atmospheric or below while I went to the DMV and back.

At Idle It runs 14.6 or 14.7 when the motronic goes into closed loop
as It passes through atmospheric it creeps fatter and holds around 12:1 and moves toward 10:1 as the boost builds.


I know its running on the rich side, but I figured that would be safer for now.

Todd, you are awesome and I'll definitely call you once I get it a bit further along and have specific questions. I just don't want to waste your time on menial stuff.

[T_C_D]

What do you mean by o2 clamp?

At Idle It runs 14.6 or 14.7 when the motronic goes into closed loop
as It passes through atmospheric it creeps fatter and holds around 12:1 and moves toward 10:1 as the boost builds.

You need colder spark plugs but that isn't your issue. Seems unlikely you have detonation as rich as it is unless you have an isolated issue with an injector.

You will need an 02 clamp to trick the ecu so it doesn't lean of the fuel over time.

[al525i]

so here's where things are:

friday afternoon I got the car in the shop and went through some things and have the following thing figured out:

The wastegate had the large blue spring installed which translates to 14.5psi


So, I put in the small green spring for 7.2 psi (its the lowest pressure spring I have)


That has helped a lot with the pre-ignition but I'm still having a little bit when the car warms up if I keep my foot in it too long. I can't see the fuel pressure while I'm driving but I'll get a longer line so I can run it out of the hood. At idle I've got 42 lbs of pressure. I do think its possible I''m dropping fuel pressure under load and I'll explain my reason below:

The wife and I drove the car to the gulf coast of florida saturday morning and I found out that at around half a tank I'm having fuel supply issues. Its also possible that the pump is getting weak as it heats up but I'm not sure. I know the in tank pump is working fine but I guess its time to go ahead and just upgrade the pump/pumps. I've read about the walbro 225's but I've also looked at the aeromotive A750. Are there any benefits of staying with a frame mounted pressure pump or is it better to move to an intank pressure pump?



I've also got to order a 528e differential mount because I already see a rip starting on the brand new mount with 430 miles on it


I did some research on the o2 clamp and the only thing I can find seems to be referenced to miata's. I get the idea of how it works and I know its the same principle in this application but I'm wondering: Is this something that is a stop gap fix for the motronic or will it be required with megasquirt also?



on a positive note though, Man it felt good to just drive it! Prior to this weekend, Its had less than 900 miles put on it in the last ten years. I've missed the e28 drive so much

[T_C_D]

The wife and I drove the car to the gulf coast of florida saturday morning and I found out that at around half a tank I'm having fuel supply issues. Its also possible that the pump is getting weak as it heats up but I'm not sure. I know the in tank pump is working fine but I guess its time to go ahead and just upgrade the pump/pumps. I've read about the walbro 225's but I've also looked at the aeromotive A750. Are there any benefits of staying with a frame mounted pressure pump or is it better to move to an intank pressure pump?


I did some research on the o2 clamp and the only thing I can find seems to be referenced to miata's. I get the idea of how it works and I know its the same principle in this application but I'm wondering: Is this something that is a stop gap fix for the motronic or will it be required with megasquirt also?

Properly operating fuel system is a prerequisite otherwise it's death to you headgasket or piston ring lands. Any good fuel pump is fine. External/internal it doesn't matter.

O2 clamp required for Motronic 1.3 only. I have them in stock.

[al525i]

Thanks Todd,

I'll call you this afternoon when I get a minute and go ahead and order the o2 clamp.

I know the fuel system has to be right, but its very weird the way it acts. I've been watching the wideband like a hawk and when i hit boost it never goes rich. the only time I held into it at all I saw it start to creep back up towards stoichiometric but dropped out of the throttle before it got to 13.0:1. When It transitions to boost I'm actually bottoming off my gauge with is somewhere richer than 10.5:1

I had been cruising down the interstate and keeping it intentionally out of boost and it stayed around the 13.8-14.7 range unless I dropped completely out of the throttle and the motronic cuts the fuel off completely. It was only when I got off the interstate that the fuel problems appeared in the form of completely falling on its face if you got anywhere near boost. It didn't run lean, it just acted like it was a total fuel cut. Stopped for lunch and headed straight for the gas station thinking I may actually be out of gas. It held a little over 8 gallons so It clearly had fuel in it still. BUT, the problem was gone.

Since the fuel pumps tested good but are not new I'm going to just replace them. It looks like an in-tank is the way to go and I'll make an adapter from brass to tie the lines together where the stock main pump is.

I've also still got the off idle stumble that causes me to have to feather the throttle at stop lights so I don't stall the engine.

[T_C_D]

Sounds like too much fuel pressure and you are hydro looking the injectors.

[al525i]

Thanks for the time today Todd, I'll update with more when the new parts are installed.

one other question I forgot to ask earlier,

With a stock head gasket and ARP studs, Do I need to re-torque the head? I'll be going into it this weekend to do a 500 mile valve adjustment / inspection and its the perfect time to retorque if needed.

[T_C_D]

Thanks for the time today Todd, I'll update with more when the new parts are installed.

one other question I forgot to ask earlier,

With a stock head gasket and ARP studs, Do I need to re-torque the head? I'll be going into it this weekend to do a 500 mile valve adjustment / inspection and its the perfect time to retorque if needed.

I would since you in there.

[al525i]

Okay,


got the chip installed and that fixed the pre-ignition I was experiencing completely so it was just timing set too high. I'm slowly leaning the begi out but its still pretty fat so I know I'm leaving power on the table.

the o2 clamp; how does it get wired into the system? does it go in series with the signal wire from the o2 sensor to the computer?

I'm also still having a fuel issue. Its only when the tank is lower than about half a tank and only when the car is warm. I have great power and then all of a sudden it cuts out. Doesn't go lean first, just acts like the fuel cuts off. Let off the throttle and it comes back and runs fine again. Here are the thoughts I have currently:

- bad fuel pump (either main or transfer) that works fine but under hard acceleration is internally shorting out from possible bearing play and shutting down
- fuel tank is sloshing fuel away from the pickup (but since it happens at half a tank and only when warm I'm not keen on this one)
- bad electrical connection going to one of the fuel pumps. (again, since it only happens when hot and only when the tank is low I'm not keen here either. Also I just replaced All the fuel pump wiring and connectors two months ago)

[tschultz]

I'd recommend a 255lph fuel pump. I have a full write up with part numbers that I used in my 633 project thread (page 4?).

I opted to keep the intank pump and replace the main pump with the higher capacity unit. No issues so far, but I likely can't build as much pressure due to limits of moving fuel through the (dead) lift pump.

[T_C_D]

the o2 clamp; how does it get wired into the system? does it go in series with the signal wire from the o2 sensor to the computer?

Yes

[offroadkarter]

I opted to keep the intank pump and replace the main pump with the higher capacity unit. No issues so far, but I likely can't build as much pressure due to limits of moving fuel through the (dead) lift pump.

Dead lift pump is acting as a major restriction with fueling. I wouldn't be tracking a car like that.

[al525i]

Yesterday I did some research and have ordered one of aeromotive's 340lph stealth in-tank pumps. I know its overkill currently, but I do plan to go intercooled and up the boost later so I'd rather get all the supporting stuff done as areas are addressed

[shawnoc]

I'm gathering parts for a similar build, so thanks for sharing.
Any update?

[al525i]

I do need to do a proper update, and will soon.

I have done a bit over 2000 miles in the past month in the car (1,610 in four days going to vintage last month)

and it runs good overall. The new fuel pump fixed the lean issue but has given rise to another one. Under boost I go pig rich and nothing seems to help to lean it back out so far. Last week I put the 10psi spring in the waste gate and it isn't as rich now but still not right. (now I'm not bottoming out the wideband but still getting around 10:1 afr's under boost)

I think its just going to have to run megasquirt and stop playing with the work arounds.

beyond that though, I've washed it a couple times and put gas in it. That is it. It seems like I have the e28 I've always wanted now and enough power to keep me happy for now.