Fuel Injection Help!

[TR7Spider]

Hey guys!

I'm having trouble with my fuel injection system on my 1980 TR7 Spider. I'm hoping you guys might help or have some insight in the Bosch fuel injection system. Ok here's the problem: My fuel mixture is running very lean and the HCC are high (850-1000) and thus won't pass emissions. It was running fine last august but now it is running poorly and the idle is uneasy when stationary. When I'm driving, however, it seems to be running fine. I tested to see if there are any vacuum hose leaks, but there are none. I have replaced a lot of FI parts, please see below. It also has the original fuel injectors. I'm thinking I might need to tighten the spring on the mass air flow sensor or even replace the fuel injectors. Please let me know what you guys think.

Cheers!

Parts:
Bosch O2 Sensor
(2) FI Intake Hoses
(4) FI Air Plenum Tube Hoses
Cold Start Injector
Spark Plugs

PS its a Californian TR7.

[HDRider]

There is a lot of FI information on TR8.com. It is for the 3.5 liter V8 but the TR7 system is very similar. It will tell you how to test most of the components. The big difference between the two systems is that the V8 system has a potentiometer for the throttle position sensor whereas the TR7 uses a open/closed throttle sensor.

Edward Hamer
Petaluma CA

[TR7Spider]

Thanks Edward. I've already read up on the tr8 page. Unfortunately, the TR8 Lucas fuel injection system is very different than the TR7 Bosch fuel injection system. I've got a lot of manuals and Bosch FI diagnosis books, but just want to see what you guys think based on your experiences.

Cheers!

[darrellw]

Have you changed the fuel filter? Checked the fuel pressure? Verified the ignition and timing are good? Made sure the flap in the air flow meter isn't sticking?

Also, the AFM should have a screw to tune the idle mixture. There are test connections for the V8, not sure of the procedure for a TR7.

Darrell Walker
66 TR4A IRS-SC CTC67956L
81 TR8 SATPZ458XBA406206
Vancouver, WA, USA

[TR7Spider]

Fuel pressure is good, I changed the oil 200 miles ago with a new fuel filter and oil filter. Timing seems to be good, I'm going to replaces the plugs and wires soon. I did tune the idle mixture used by the screw on the AFM but it is misbehaving and doing its own thing. I am changing out the AFM tonight. I'll see if that makes a difference.

[jclay (RIP 2018)]

Contact Jim TenCate. He and Micheal Hart have developed a "Gizmo" for checking the TR7 system as well as the TR8 one.

Clay

[url="http://www.jclay.me/"]My Triumph Site[/url], [url="http://www.triumphtechnical.me"]Technical Stuff[/url], [url="https://docs.google.com/folder/d/0B8MWEvqOpX3udEF4SmFQUW9RS09hbU5uNW5Wd0xrUQ/edit"]My Public Folder[/url],

[FI Spyder]

I've taken a look at the OEM manual for idle problems and diagnostics, other than after the AFM leaks, check to make sure the Aux Air Valve is working. How to do this should be in the Manual (1980 or newer).

- - -TR7 Spider - - - 1978 Spitfire- - - - 1976 Spitfire - - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra - Yellow TCT

[TR7Spider]

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by jclay</i>

Contact Jim TenCate. He and Micheal Hart have developed a "Gizmo" for checking the TR7 system as well as the TR8 one.

Clay

[url="http://www.jclay.me/"]My Triumph Site[/url], [url="http://www.triumphtechnical.me"]Technical Stuff[/url], [url="https://docs.google.com/folder/d/0B8MWEvqOpX3udEF4SmFQUW9RS09hbU5uNW5Wd0xrUQ/edit"]My Public Folder[/url],
<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

Thanks Clay, I will have to ask Jim. I know in order to use the tool, you have to be a TWOA member. I think the tool is used to adjust the air/ fuel mixture by a cable under the dash. Is their a contact for Jim?

FI Spyder, thanks for the help. I was wondering too if that working. The auxiliary Air Valve should be closed at warm temp. I will do a light test later tonight. Thanks for all of the help!

[darrellw]

There's actually two tools. The Gizmo is for adjusting the idle mixture, it connects to the test electrical connection. It can also be helpful to see what the ECU thinks is going on as far as the mixture. The other tool is a variation of the "Shoebox" tester that many in the VW crowd use. It is used in tandem with an ECU wired up to allow you to monitor all of the signals to and from the ECU.

Some pictures here:

http://www.triumphwedgeowners.org/fi-di ... pment.html

Darrell Walker
66 TR4A IRS-SC CTC67956L
81 TR8 SATPZ458XBA406206
Vancouver, WA, USA

[TR7Spider]

Darrell thank you for your help. I actually have a Bosch Fuel Injection Component Tester for 4/6/8 cylinder engines. It is a FI L-jetronic tester. The lucas FI ECU Tester is very specialized and is used for TR8s.

Since my last post, I have since taken out the AFM. I found out that the Measuring flap bearing was non-existent, allowing the AFM to do as it pleased. The spiral spring had so much play at idle, it was causing my FI system to run lean. I have changed it out with a spare from a low mileage 80 TR7 and it seams to be running fine. There is a little hesitation however at idle. I found a source for new fuel injectors and seals for around $80. I'll change them out and let you guys know the results.

Thanks for all of your help!

[TR7Spider]

UPDATE:

Since my last post I have replaced the Spark Plugs with NGK G-Power plugs (perfect plugs for early Bosch fuel injection systems). I have also replaced the distributor rotor, distributor cap, and plug wires with correct OEM parts.

As a result, the timing is a lot better than it was but it still idles uneasy at times. I tried adjusting the Air Mixture by the screw on the AFM but it didn't help with the idle.

Since then, I've taken all of the fuel injection components out of the engine and have checked each electrical component for faults. I found out that the injector connection for cylinder 1 was incorrectly placed on the cylinder 2 fuel injector. The same was done for 3 and 4. My old triumph mechanic (who I don't go to anymore for obvious reasons) had replaced the cylinder head gasket and had messed with a lot of the FI components while the head was replaced.

I will be putting everything back together tonight. Wish me luck! I will take detailed pictures of the FI system if any of you need pictures for your TR7.

Cheers!

[Stag76]

It's a batch fire system, so as long as 1&3 are on one channel, and 2&4 are on the other channel it should be OK. You can also pair 1&4 on one channel, and 2&3 on the other, but the first pairing will probably give a slightly smoother idle. The injector firing method (ie no of pulses per cycle, and whether simultaneous or alternating) also influences the best pairing method.

The best method is to try different pairings to find the best idle. I have seen all sorts of combinations, including 1&2 and 3&4. They all seem to work, except for a sequential injection system, which the TR7 isn't. My Stag worked best with 1,4,6 & 7 on one channel, 2,3,5 & 8 on the other channel, 2 Squirts Alternating per cycle. My Sprint motor is wired with 1&4, and 2&3, the same as the wasted spark ignition.

TR7 Convertible
Sprint Motor
MegaSquirt EFI