OK, I need help. I was driving relatively low speed when I hear what sounds like a gear grinding, it was really quick and then gone, and then I lose power. It accelerates but seems to be firing only on two cylinders.

WHAT JUST HAPPENED?

I am so bummed as i just got this car back running with the FI.

Any one have a super cheap Engine close that I can get to install this weekend?

Lost a spark plug?

Really? I'll check.

the plugs look ok from the top, I tried to pull using my socket and It doesn't seem deep enough to grab. Funny how it worked on my other cars. I'll have to buy a socket and pull them this afternoon.

I had this happen on another car but the plug looked like it exploded. Is that how you tell or could it look ok from the outside and get fried internally?

If you lost a plug you would know it. They're loud! Does it turn over with the key? Pull the distributor cap and watch the rotor while someone spins the engine. Remove coil wire when preforming test. If all is good, find which cylinder is not firing by removing plug wires one at a time with it running. You'll hear and feel the engine bog down with one wire removed. If it doesn't, thats your bad cylinder(s).

Might not be the plugs or spark wires, but pull the plugs to be sure. Check ALL your wiring though, especially the wiring plugs to the injectors ... I've had them come loose on my wife's 1.7 a couple of times (they've wiggled out because she's missing the rubber boots).

Also you can check and clean (if needed) the trigger points.


While you're in there, might want to check the following as well:

Valves adjusted properly?
Cap, rotor & plug wires OK?,
Dizzy secured?
Dwell angle? (if running points) .016" gap

I did that and I can pull cylinder 1 n 2 with no change but 3 or 4 stop the engine.

I have one side not firing and I think it's worse than just a plug. Never heard of two plugs going at once.

trigger points?

I have seen a spark plug loose the diode in the middle.. But it doesnt sound like thats your problem.

Is there any current engine noise that is abnormal?

Could be something fuel related as well.

Not likely. Each contact does one cylinder on each side.

The Cap'n

No abnormal sounds, only that it sounds like its only firing off 2 cylinders.

I lost cylinder 1 n 2 on the drivers side. hmm

No heavy clanking or anything else.

Might want to use a timing light to see if you're getting spark in the "bad" cylinders. If you verify that have spark, then your fuel injectors might not be firing.

Pull each spark plug while its running. See if pulling any result in the engine running different than the rest.. You should be able to determine if you are either missing spark or fuel in that particular cylinder.

The engine needs three things to run: Fuel, Air, and Spark. Check for each of those. For Air, use a compression test. For Spark, you can grab an extra spark plug and tape it so the outer electrode or the threaded part is touching a ground. Have someone crank the starter and look for sparks at the plug.

For fuel, you can be pretty certain you have it if you smell fuel at the tailpipe after cranking the starter for a while (say, with the above tests). But you can also pull the injectors on that one side (just one nut holds each one in) and stick them in jars. Have someone crank the starter (unplug the coil wires first!) while you look for the fuel spray. You want a spray, not a dribble.

If those check out, then the culprits are either when the spark happens (unlikely with just two cylinders), or how much fuel is going in (harder to figure out).

But a sudden loss of 2 cylinders is most likely either spark or fuel.

How's the distributor cap look? Is it on correctly?

--DD

If you have two dead cylinders and nothing is wrong with your plugs or wires, check inside the distributor cap. Watch the shaft turn. You might have big old wobble. But look at the cap first. Evidence of this will be found there.

a nasty backfire could blow out your MPS

Just thought I'd add trigger points to the list in case all the other possible remedies produced negative results.

The ones on my wife's car had a build-up of grease on the contacts and needed to be cleaned up.

If the engine's wiring harness is old and brittle, you could have broken conductors. Check for voltage at the injector plugs for the two offending cylinders (while cranking the engine). They should be pulsing voltages, so best too check with an analog voltmeter.

If no voltage readings are present, perform an end-to-end check of the wiring from the injector plugs to the connector on the ECU.

Highly unlikely.

The Cap'n

And if the MPS was blown, it would make the car run rich (if Djet anyway), not knock out two cylinders.

I don't know enough about this, so just asking: Could something have happened to the valve train on that side?

It seems odd that it should hapopen all at once. Were you doing anything unusual when it happened?

My first guess is that you mentioned that you just got it running. Did it sit for a while? Perhaps something is blocking the fuel rail on the dead side. This doesn't explain the grinding sound though.

John

Just got it running maybe three weeks ago after sitting for about a month.

The sound was strange. It was short, load and ended quick. It was like I ginded going into a gear but i was just cruzing at 25mph at maybe 2500rpm or 3k. Then it lost power.

I was able to barely get it home. It idles but slowly and removing cylinder wires identified that Cylinder 1 n 2 are not firing but I haven't been able to do much more with it yet.

I let it idle and listened for any mechanical but it seems to turn fine just not firing.

If it is the Distributor some how, then I don't have a spare.

If it's just spark plugs then I can get those.

What if one Side of the trigger points were to go? would that create this condition?

See post #11

The noise is what disturbs me. What, that could cause this, would make a loud mechanical noise when it went out? Sounds like something broke, and that would probably cause damage you could see if you could get your eyes & hands on it.

I've not heard of one side of the trigger points going but if they are only partially plugged in to the harness the car will still run but badly...

What do your points look like? Look inside your distributor cap and see if the carbon contact is broken off. Check inside the cap and look for cracks, arching etc...

Crank breaking?

I agree with the valve train idea. Only take a second to take off the V/C on that side too.

This is probably a long shot but could it be something in the heads like stripped bolts in the valve train?

It would definitely start with Dave's list of tests on post #15. It will allow you to narrow down the subsystem that is at fault.

John

I had a similar experience in my brothers TR4 racer.

We were running around the track and the engine made some horrible noises, then ran like crap missing & farting.

We limped back to the paddock, pulled the valve cover expecting the worst.

ONE of his rocker bolts had broken so only half of the valves were still working.
The ones on the bad side were either barely opening, or stuck shut.

I'd pull the cover.

Stu

sheared roll pin for the dizzy drive gear?

dizzy not properly installed [skipped the drive for a while] and not tight?


just some thoughts.....

broken cap and rotor. just takes being cracked to cause problems.

With the loud noise you mentioned, and all the input provided, its starting to sound more logical that it's a valve train issue.

It is possible that the rocker arms either lost their adjustment or came loose on that side of your engine