1985 X 1/9 Stock Engine Stalls

[LoveX1/9s]

My car stalls and it's a bit of a mystery. Unless it happens to you it's hard to describe. At 65 mph, it quickly and smoothly shuts down in a matter of yards. It's almost like short and controlled breaking without any hesitation but the breaks aren't engaged.

Sometimes, it will buck a few times spread out over over a long ride but never stall. However, it rarely bucks.

It's never stalled at night but when it bucks, the headlights stay on.

It's shorted in the past however but that hasn't happened after replacing the power window switches.
That said, the interior lights have never worked and radio and clock come and go. The fuses are intact. I thought perhaps the electrical board is on the way out but who knows?

The car starts fine and runs a mile or 2 and sometimes for days and just stalls without warning. Sometimes it will restart after 20 minutes and some times it may take a day or 2.

It never stalls when idling. In fact, I tried that for over an hour and it was fine.

I replaced the fuel pump, coil (it's rare but it went bad), fuel regulator, filters and there are no vacuum leaks.

The car is fuel injected.

Any thoughts? Thanks in advance for your replies.

 

[ng_randolph]

Have you noticed what the tachometer does when this happens? If it quickly drops to 0, the problem is likely lack of spark (Ignition control module failure, ignition switch failure etc.).

The ignition switch has two "on in run" outputs, so the fact that your headlights stay on does not necessarily vindicate the ignition switch.

 

[myronx19]

Yes - I've had similar issues - so what I've done is cleaned out my AFM connector using contact cleaner, and plugging it in and out a few times. That was the cause of my issue - never left me stranded, BUT - has caused similar issues.

Other than that, I also had an issue where my coil wire was not fully seated in the coil.

The interior light fuse is an inline type - it's also set with the clock if I recall Any pics of the engine bay, just to get an idea of the overall condition?

 

[kmead]

Check the wired connection to the coil from the distributor, the doubled spade connector can have a poor connection to its mate to the wire from the distributor.

The pickup in the distributor could be failing, there is a test in the manual for it.

Have you checked the spring loaded button under the distributor cap? I had one disappear and had only the spring which then arced inside the cap to the wrong cylinder post.

 

[Jonohhh]

I third checking the + and - connections on the ignition coil. That exact connection has brought me to unexpected halts on the side of the road on a number of occasions, until I finally took the time to use a pair of channel locks to "re form" the spade connectors to increase the clamping force.

Given how they are connected and routed, they should honestly be stud and nut connections a the way to the wires, with no spade, but that's just my opinion.

 

[Jefco]

Check the coil connections, including the FI trigger wire. Tight and shiny?
Check the double relay connections, especially if you have removed it. All terminals uncorroded and fully engaged?
If suspect, there's the FI troubleshooter

FuelInjectionTroubleshooting - X1/9 Wiki

xwebforums.com

 

[LoveX1/9s]

Have you noticed what the tachometer does when this happens? If it quickly drops to 0, the problem is likely lack of spark (Ignition control module failure, ignition switch failure etc.).

The ignition switch has two "on in run" outputs, so the fact that your headlights stay on does not necessarily vindicate the ignition switch.

I haven’t. However, my guess is that it does because the car spins down and probably isn’t getting gas either. However, I saw a post else where that the tachometer bounces around. In my cause, I didn’t notice either. I will check that though given that the car stalled, in the mountains and I had to take it to a hack up there. The ignition fried when trying to start it. He put in a new switch but may have spliced it in.

 

[LoveX1/9s]

Thanks everyone. I will try all of the above.

 

[alskin]

My car stalls and it's a bit of a mystery. Unless it happens to you it's hard to describe. At 65 mph, it quickly and smoothly shuts down in a matter of yards. It's almost like short and controlled breaking without any hesitation but the breaks aren't engaged.

Sometimes, it will buck a few times spread out over over a long ride but never stall. However, it rarely bucks.

It's never stalled at night but when it bucks, the headlights stay on.

It's shorted in the past however but that hasn't happened after replacing the power window switches.
That said, the interior lights have never worked and radio and clock come and go. The fuses are intact. I thought perhaps the electrical board is on the way out but who knows?

The car starts fine and runs a mile or 2 and sometimes for days and just stalls without warning. Sometimes it will restart after 20 minutes and some times it may take a day or 2.

It never stalls when idling. In fact, I tried that for over an hour and it was fine.

I replaced the fuel pump, coil (it's rare but it went bad), fuel regulator, filters and there are no vacuum leaks.

The car is fuel injected.

Any thoughts? Thanks in advance for your replies.

I had the same problem with my 1982 X1/9 with fuel injection. It would cut out at higher RPM when driving. only sometimes. but never at idle. I believe I was losing fuel pressure. should be about 40 psi. since my car has over 100k on it I replaced with a new bosch fuel pump, fuel filter, pre- fuel filter between the fuel tank and electric fuel pump and fuel pressure regulator. Test drove it for 50 miles and so far no engine cut out. how is your gas tank inside? If you have sediment inside it may clog your fuel pump and you will lose fuel pressure. hope this helps.

 

[Larry]

Another thing to check is the wiring harness for the fuel pump. It should be inside rubber tubing. I removed the harness and when I looked, the wires inside had bits of insulation missing and showed signs of shorting out against each other.

 

[Dan Sarandrea (Phila)]

I had the same problem with my 1982 X1/9 with fuel injection. It would cut out at higher RPM when driving. only sometimes. but never at idle. I believe I was losing fuel pressure. should be about 40 psi. since my car has over 100k on it I replaced with a new bosch fuel pump, fuel filter, pre- fuel filter between the fuel tank and electric fuel pump and fuel pressure regulator. Test drove it for 50 miles and so far no engine cut out. how is your gas tank inside? If you have sediment inside it may clog your fuel pump and you will lose fuel pressure. hope this helps.View attachment 58356View attachment 58356

Very nice looking car!

Just wanted to offer a friendly correction to your post.

According to the FI troubleshooting guide (pages 1 and 3):
a. Normal operational fuel pressure is 28 psi
b. The stock fuel pressure regulator max pressure is set for 36 psi, +/- 3 psi
c. Not sure where your 40 psi figure comes from
d. Max fuel pressure for the system during testing is 50 psi

 

[fto1982]

Check for bad connection at the temperature sensor under the thermostat housing. The engine will cut out intermittently or not start/run if the connections are bad. I replaced the factory connector with spades (red in photo). Good luck

 

[LoveX1/9s]

Hi everyone. The coil was shoot replacing it didn’t fix the problem. I hear when that happens, the fuel injection “brain” is the problem. So far so good. It appears to be running fine now. Thanks for your input.