TR Won't Idle

I’m not familiar with that engine. I believe it uses a mechanical fuel injection system.
The combination of symptoms leads me to believe your TR suffers from a fuel leak possibly in the fuel distributor. I would not drive it until you get this corrected.

 

Mine did this as well. Open the front fuse panel and replace BOTH fuses and relays for the LH and RH fuel pumps. That should cure it. If not you'll have to dig a little deeper

 

Sounds like your only running on one bank of cylinders. Check your coil wire connections, and pull the boot back on the distributor and make sure everything under there is in good order. Now go on up to the fuse panel etc and inspect all large plug connections, pay very close attention to the lower most horizontal plug on the drivers side of the fuse panel. Remove the plug and look for signs of burnt connections. Repair and give it a try.

 

I just had the same problem. Lost the left bank. The warning signs were interesting. First, intermittent loss of power for a second or so every five mins. Then on the track ( I was on my way there) it lost power for longer periods, 5-10 secs. On the way home, no left back at all for 200 kilometres.

My friend and mechanic worked out the issue was in the mechanical injection. He pulled it down and found a rod was sticking. He basically cleaned the unit by soaking it in something. It fixed the issue, he then cleaned the other one.

The car goes harder than ever in the top end. Total labour about 5 hours.

Hope this helps a little.

PV908

 

I've had this problem as well, although in my case there wasn't a strong gas smell. A strong gas smell would indicate to me a spark problem as clearly you're getting fuel and air. You can pull the plug wires off and hold them near a ground to see if you're getting spark. It's a quick and dirty test. Possibly not healthy for the coil but it works.

In my case, fuses and relays and ignition components were all good. My problem was at the fusebox connector where the big white quick-disconnect plugs plug onto the board. Over time those connections weaken and cause intermittent or no-contact situations, especially with the higher current items like fuel pump (in my case) or cooling fans. In a lot of cases you can see the connectors warped or burned from the heat. The fuel pump wires are on the connector that's bottom right as you're looking at the fusebox from the front of the car. Pull off that quick disconnect and make sure the little U shaped prongs in the plug are not wide apart.

I also at one point had a fuel pump wiring harness rub-through and short out in the back of the car near the frame rails. I didn't fix that one myself, so I can't tell you exactly where it was, but it's another thing to check.

 

Where is the smell of gas coming from? If the smell is coming from the exhaust, then it’s an ignition problem.

I’m still thinking fuel distributor.

 

Above to what has already been mention, be sure your fuel accumulators are not leaking

Same problem with mine and I could see the fuel seeping from one of them

 

My 84 911 had exactly the same symptoms, strong gas smell, won't run. It also has the bosch k jetronic fuel injection.

I cranked and cranked, eventually the problem was traced to a faulty electrical connector in the wiring harness (the engine had been out for a clutch and a connector was left loose by the shop). One wiggle (and some dialectric grease) and it started right up. It seems that even without a spark, the CIS will keep the fuel flowing, so a strong gas smell was present. My thought is to check the notorious long white electrical connectors in the fuse box, add some dialectric grease and try it. Worst case scenario is that you cleaned and greased your electrical connectors.

As I recall, the wiring harness plug in the 911 which was at fault was the one that deilvered the flywheel sensor signal, so maybe check the wiring connector on that too. Maybe a 911 is like 1/2 of a testarossa.

My $0.02, anyways.

Good luck.

 

Your symptoms are definitely similar to the ones I had. No popping of banging.

The car struggled to get to 3000 revs but would get there. It would also struggle to idle.

We also checked all the electrics because we were weary of the mechanical injection. I really think if you have lost a bank, after the tests you have already gone through, that a simple cleaning of the mechanical injection may solve the problem, it can be diagnosed by measuring if fuel is flowing freely into the system. Don't quite know how he did it but am happy to give you his phone number, the diagnosis took 5 minutes.

PV

 

Check the fuel accumulators.

 

I traced mine to a severly blocked fuel filter. It was very hot to the touch. Wasn't supplying enough gas to keep the engine running. Strong fuel smell could be all the cranking you are doing and flooding the engine. Will the engine run at high rpms but not idle?

 

That is sad that you paid him all of that money and he replaced parts that were more than likely fine. He shouldn't have let it leave without being repaired correctly. If the problem is exactly as you say not getting enough fuel when cold; pull the cold start injector (one on either side) when the engine is cold and see if they spray. If they don't spray when could you have found your problem. Then you need to check them manually to make sure they function which most of the time they are ok. Then go and check your thermo time switch/es. These can be checked with a DMM. I would like to see your fuel pressures, cold control, warm control etc. A less likely problem is a warm up regulator. When they stick lean you can start the car and it will immediately stall due to fuel starvation. Keep us posted. The more info you can provide the better. Next time start it up after you perform your cold starting tests check for spark on all cylinders. You can do this easily with a timing light. I just want to verify that spark is present on all cylidners cold/warm. Sometimes electrical issues only show up when engine is warm or cold when they are in their infant stages before growing to large problems. Let us know.

 

Jerry,

Can you please explain this further. Are you saying that if you introduce extra fuel into the intake system it will cold-start and then it runs well (without adding extra fuel), or to keep it running after it cold-starts you have to keep adding extra fuel?

 

I would check your fuel pressures. This way you know if your control pressures are OK. If they are off your car will run badly.

 

Your thinking is along the right track here IMO except it's more likely that you've lost the +12V power to run the KE-Jet system. Unlike the (dumb) K-Jet without Lambda systems, on the KE-Jet systems (both with and without Lambda) the amount of fuel delivered is dependent on both the position of the airflow metering plate AND the EM valve (which needs +12V power going to the injection ECUs to function).

Do a search on "red wire triangular black box" -- should get you ~5 threads that all have information on this subject. Essentially, what you need to do is confirm/deny if +12V is present or not (during starter cranking and/or engine running) on the red wire going to the water temp switch on the LH side of the Aluminum water housing that also holds the thermo-time switch and the coolant temp thermister (that red wire is part of the same network that puts +12V power to the injection ECUs).

Give a shout if you need more information.

 

I've never seen 91TR-Steve falter/stumble/be wrong. Clever bloke!

 

Thanks for the kind words Gentlemen, but the symptom (both banks barely running at the same time in a sudden way) did point the blame in that direction.

KE-Jet = all the usual troubles of a K-Jet + an extra horde of electrical gizmology to go wrong