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'97 Honda 300EX - TL1000R engine swap
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Discussion Starter · #1 ·
Hey all, long time lurker but I had to make an account because I'm burned out on the old search box. I recently acquired a four wheeler with a TLR engine (not sure which year but 4 injectors and ECU being a "-02FD0" model make me believe its an R). Anyway, I've searched and searched trying to figure out why my injectors won't spray. They're getting + power from the yellow and red wire but the ECU is not grounding them, completing the circuit and firing the injector. one will spray sometimes, but I think that one was just open last time the bike ran properly. Do I need the fuel pump connected for the injectors to fire? What sensors are needed to get power from the ecu to the injectors? Because that's a whole different issue, I will be running an external pump once I decide caravan or GSXR and mounting on the ATV frame. I've read all the posts I can, I have most of the sensors (only throwing codes for IAT which is missing and IAP which is just not working and I cannot swap with baro sensor because that's also missing lol.

Thanks in advance!
 

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1998 TLS; 2001 TLR; 200X TLRSF
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Welcome to the Zone TTN!

There are only a few different error codes that will inhibit the ECM to prevent the starting process. As you can see on the list below, the camshaft position sensor (CMP), error c11, is one of them. The other ones that come to mind are the crankshaft position sensor (CKP), error c12; ignition switch error c42; and the tip over sensor (TOS), error c23. However, at least in the case of the TOS, it would cut power to the injectors and fuel pump by means of disabling the fuel pump relay. Since you have power applied to the yellow/red wire, then apparently the relay is still active.

Although it may not be starting for many reasons, if the errors above are not present, it should try to start. Which means the ECM should still be generating the commands to fire the injectors.

How did you determine that that ECM is not commanding the injectors to fire? Noid lights? Oscilloscope? LEDs?

Have you tried spraying starting fluid directly into the throttle bodies? That may help you narrow down the possibilities.

One more thought. If the injectors have been sitting for a long time, they could be clogged with old varnished fuel, and consequently not able to open.

TLR 4-30 by Tony Six5, on Flickr
 

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'97 Honda 300EX - TL1000R engine swap
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Discussion Starter · #3 ·
Welcome to the Zone TTN!

There are only a few different error codes that will inhibit the ECM to prevent the starting process. As you can see on the list below, the camshaft position sensor (CMP), error c11, is one of them. The other ones that come to mind are the crankshaft position sensor (CKP), error c12; ignition switch error c42; and the tip over sensor (TOS), error c23. However, at least in the case of the TOS, it would cut power to the injectors and fuel pump by means of disabling the fuel pump relay. Since you have power applied to the yellow/red wire, then apparently the relay is still active.

Although it may not be starting for many reasons, if the errors above are not present, it should try to start. Which means the ECM should still be generating the commands to fire the injectors.

How did you determine that that ECM is not commanding the injectors to fire? Noid lights? Oscilloscope? LEDs?

Have you tried spraying starting fluid directly into the throttle bodies? That may help you narrow down the possibilities.

One more thought. If the injectors have been sitting for a long time, they could be clogged with old varnished fuel, and consequently not able to open.

TLR 4-30 by Tony Six5, on Flickr
Wow man I must say thank you for all your posts, I would call you king of the Tiller lol. I have c22 and c23 which according to that list shouldn't stop the bike from spraying fuel. Usually I fight with people about "My ECM is bad" because it generally isn't, but I read somewhere else (either here or TL Planet) that these can go bad in just this same way. Checked the wires with a couple different multimeters and also an LED diode, got nothing except that occasional spray from the front primary, but it doesn't even cough and try to start when that one sprays. I have started it with starting fluid and gas down the throttle bodies, that couple seconds of V-twin rumble is my driving force for getting this thing going. I have pulled the rail and cleaned it out, tested with compressor and injector cleaner and a 9v and it all went smoothly, all sprayed correctly/evenly.

One thing I will try later is checking the wires at the ecu end of the plug, this harness was re-wrapped with little care, and I can't even find the plug for the atmospheric pressure sensor. I've been looking for a parts bike but nobody wants to sell scrappy high mile TLRs near me haha. Has anyone ever switched one of these to fully standalone fuel and ignition management? I'm sure they have for forced induction but I just feel like it's a better deal to make that upgrade then chance this happening again with a $200+ irreparable/art-project-to-dissolve Poly filled unit lol. Plus with having 4 wheels I could turbo it down the road if I really have a deathwish.
 

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....Usually I fight with people about "My ECM is bad" because it generally isn't, but I read somewhere else (either here or TL Planet) that these can go bad in just this same way.
I agree. The TL ECM is generally a fairly robust device. However, after 20 years, with many of these electronic modules being sold and resold, shipped, handled, hot swapped, and installed into one project after another, it should be no surprise that more and more ECMs are showing up with unusual failures.

In your case, however......

Checked the wires with a couple different multimeters and also an LED diode, got nothing except that occasional spray from the front primary, but it doesn't even cough and try to start when that one sprays.
A multimeter generally is not fast enough to detect the injection pulse from the ECM, so I wouldn't put too much confidence in that test. A diode (wired properly) should emit a visible flash when the pulse occurs.

Still, you also say there is an "occasional spray from the front primary" injector. That being the case, I would rather suspect the problem is not within the ECM itself. If the internal circuit failed, it would most likely not fail in an intermittent fashion, but it would be dead with no output at all. The intermittent nature of the injector control points to faulty wiring or connector terminals, IMO.

I have started it with starting fluid and gas down the throttle bodies, that couple seconds of V-twin rumble is my driving force for getting this thing going. .....
Again, even the momentary episodes of starting and combustion, tells me the injection and spark control circuits are working.

..... I can't even find the plug for the atmospheric pressure sensor. ....
You may know this already, but on a TLR loom, the AP sensor connector is in the front half of the loom, near the headlight connectors.


Has anyone ever switched one of these to fully standalone fuel and ignition management? ......
Yes, many have used aftermarket ignition/injection modules. I don't know enough to recommend anything, but you might try searching the 'Performance' section in this forum, or put your question to the TL Groups on Facebook. The FB groups get a lot more traffic than these forums do these days.
 

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'97 Honda 300EX - TL1000R engine swap
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Discussion Starter · #5 ·
You may know this already, but on a TLR loom, the AP sensor connector is in the front half of the loom, near the headlight connectors.
Mine was definitely cut off then lol. This bike has so much weirdness in the harness but it runs when given fuel so I figured it was fine. Also I believe my occasional fuel spraying was due to me loading up the fuel line with pressure from an air tank to see if it was pressure regulator based.
 

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I just re-read your initial post in this thread, and this time I noticed you said it's missing the IAP sensor. While that sensor will not technically prevent the engine from starting, it is a rather critical sensor when it comes to taking throttle below 3000 RPM. The engine will usually idle with it disconnected, but often stall when goven throttle. The IAP sensor feedback is heavily used to determine the fueling below 3k. Below 3k the fueling relies on throttle position and intake pressure (vacuum). Above ~3k, the computations rely more heavily on throttle position and engine speed.
 

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Discussion Starter · #7 ·
I just re-read your initial post in this thread, and this time I noticed you said it's missing the IAP sensor. While that sensor will not technically prevent the engine from starting, it is a rather critical sensor when it comes to taking throttle below 3000 RPM. The engine will usually idle with it disconnected, but often stall when given throttle. The IAP sensor feedback is heavily used to determine the fueling below 3k. Below 3k the fueling relies on throttle position and intake pressure (vacuum). Above ~3k, the computations rely more heavily on throttle position and engine speed.
They're $9 on ebay, I'll order one up tomorrow when I decide if my car needs anything from there also. Hopefully that fixes my issue, I'm not super hopeful since it's not grounding but it's far cheaper than an ECU. I'll let you know once the caravan pump and IAP get here.
 
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