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1750 GTV Serie 1 US specs 1969
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Discussion Starter #1
Hi All,
next week I have to bring my beauty to the mechanic 馃槱馃槱馃槱for a check up on a cylinder that is low in compression (more than 10% vs other).
Garage is not far (1.5 mile).
Was wondering if I could drive the car there as it runs on 3 cylinder....or should I have it pick up on a flat bed.....any advise taken...thanks.
 

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Drive it. 10% low should not make the cylinder inoperative.
 

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Discussion Starter #3
Drive it. 10% low should not make the cylinder inoperative.
thanks, fortgot to mention the cylinder is not firing up at all (when pull the wire plug does not change a thing), exhaust is not as hot as other ones ...
all test done (injector, plug, wire, distribution....)
 

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I would still drive it. Is the offending cyl stone-cold, plug wet and cold, exhaust branch cold. I would start from cold and run for 30 seconds rev it and stop then pull the plug and look for oil, gas temp etc..
 

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Decades ago I put my Lotus Elan back together. It wasn't as quick as before, something didn't feel right. With a friend in tow in his 1973 Civic, we drove across town to visit a mechanic we knew. Civic still had a hard time keeping up. The mechanic didn't have time to look at it, so we drove back to my friend's place. Still trying to understand, we peeked under the hood. And then it hit me. The Lotus Twincam inherited the peculiar 1-2-4-3 firing order that Ford England was using. I had the 2 and 3 wires reversed. It was running on two cylinders. Never hurt the engine.
 

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Discussion Starter #6
Decades ago I put my Lotus Elan back together. It wasn't as quick as before, something didn't feel right. With a friend in tow in his 1973 Civic, we drove across town to visit a mechanic we knew. Civic still had a hard time keeping up. The mechanic didn't have time to look at it, so we drove back to my friend's place. Still trying to understand, we peeked under the hood. And then it hit me. The Lotus Twincam inherited the peculiar 1-2-4-3 firing order that Ford England was using. I had the 2 and 3 wires reversed. It was running on two cylinders. Never hurt the engine.
Thank you. Crazy what those little engines can do....
 

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Discussion Starter #7
I would still drive it. Is the offending cyl stone-cold, plug wet and cold, exhaust branch cold. I would start from cold and run for 30 seconds rev it and stop then pull the plug and look for oil, gas temp etc..
After a few second the plug gets sooted very quickly...still dry though no oil..does not really smell gas either.... been working on it for days with help of BellaGT...no luck...only thing I have noticed. P on the pulley is not in line/time with the journal mark/camshaft mark ....and compression is more than 10% off the other cylinder
 

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Discussion Starter #9
If timing marks are not aligned, don鈥榯 start and don鈥檛 drive it
****...done it many times.... not align my much though...and why suddenly (after winter) that happened? mystery...
 

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It has to be that cylinder's spark plug or wire or injector or something in the distributor cap.
 

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Discussion Starter #11
It has to be that cylinder's spark plug or wire or injector or something in the distributor cap.
Hi, wire to plug is new, plug is new (all of them) and I test there is a spark, now possible the injector? Distributor cap is clean, no crack.....my last hope is the injector...been recommended to add Techron fuel injector cleaner in the tank ..
 

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thanks, fortgot to mention the cylinder is not firing up at all (when pull the wire plug does not change a thing), exhaust is not as hot as other ones ...all test done (injector, plug, wire, distribution....)
I vote to flatbed it - not drive it. While I agree with brad fischer ("10% low should not make the cylinder inoperative"), apparently something else is making that cylinder inoperative.

My concern is more that you will be putting yourself and your car at risk by driving with an engine running badly; not that you will damage the engine by running it on 3 cylinders for a short distance. What's a flatbed going to cost relative to the expense of repairing the engine? Here in California the hazardous waste disposal surcharge would exceed the towing cost.
 

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One thing that Laurent has not mentioned is that he verified TDC by putting a straight rod/stick indicator into #1 and rotated the engine until the indicator reached its highest point, then verified the intake and exhaust cams had their #1 cam lobes pointed outwards and the timing marks were aligned with the marks on the bearing caps.

He鈥檚 verified proper firing order and rotor position, he doesn鈥榯 have a timing light, but the ignition timing is well retarded based on the distributor position. His SPICA fuel filter was rusted, with rust at the bottom of the canister (the car sat idle for 2 years).

He鈥檚 scoped all four cylinders and #3 looks shinier that the others; he has low compression >20% difference than the other 3, has a lower temperature on this cylinder and sees no difference when he pulls the plug wire.

Since the timing checks out, he doesn鈥檛 smell much gasoline in the oil, doesn鈥檛 hear any bearing knock, the mile or so drive doesn鈥檛 seem out of the question. He鈥檚 started up the engine numerous times during the past few weeks since his initial posts and has a low/rough idle and what he thought was a misfire on #2 or #3. If it were mine, and the car had enough power to drive on its on, based on what Laurent said, I鈥檇 baby it to the mechanics With short shifts and low rpms.
 

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Discussion Starter #14 (Edited)
One thing that Laurent has not mentioned is that he verified TDC by putting a straight rod/stick indicator into #1 and rotated the engine until the indicator reached its highest point, then verified the intake and exhaust cams had their #1 cam lobes pointed outwards and the timing marks were aligned with the marks on the bearing caps.

He鈥檚 verified proper firing order and rotor position, he doesn鈥榯 have a timing light, but the ignition timing is well retarded based on the distributor position. His SPICA fuel filter was rusted, with rust at the bottom of the canister (the car sat idle for 2 years).

He鈥檚 scoped all four cylinders and #3 looks shinier that the others; he has low compression >20% difference than the other 3, has a lower temperature on this cylinder and sees no difference when he pulls the plug wire.

Since the timing checks out, he doesn鈥檛 smell much gasoline in the oil, doesn鈥檛 hear any bearing knock, the mile or so drive doesn鈥檛 seem out of the question. He鈥檚 started up the engine numerous times during the past few weeks since his initial posts and has a low/rough idle and what he thought was a misfire on #2 or #3. If it were mine, and the car had enough power to drive on its on, based on what Laurent said, I鈥檇 baby it to the mechanics With short shifts and low rpms.
Thank you Ken. Great summary.
eould add that when bearing marks are aligned then P on the main pulley is slightly advanced. Like 1|4 inch
Will report when mechanic has dine some checkup.
as the cylinder 3seems Dry could it be the injector. I doubt but with these babies who knows.
Happy Easter
 

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thanks, fortgot to mention the cylinder is not firing up at all (when pull the wire plug does not change a thing), exhaust is not as hot as other ones ...
all test done (injector, plug, wire, distribution....)
i would not drive it at all u stilll might be able to save yourself a piston rings replacement

1- good chance the only reason u have that low compression cylinder is cause its not firing and therefore the raw gas is washing alll the oil off your cylinder bores and showing lower compression

2-driving with raw gas washing all the oil off your bores will prematurely wear your piston rings and cylinder liner sleeve

3- good chance your single cylinder misfire is just a plug, plug wire or distributor cap
 

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Discussion Starter #16
i would not drive it at all u stilll might be able to save yourself a piston rings replacement

1- good chance the only reason u have that low compression cylinder is cause its not firing and therefore the raw gas is washing alll the oil off your cylinder bores and showing lower compression

2-driving with raw gas washing all the oil off your bores will prematurely wear your piston rings and cylinder liner sleeve

3- good chance your single cylinder misfire is just a plug, plug wire or distributor cap
Thank you. More complicated thank that regarding plug and wire. goes beyond this simple issue.
car will be towed to garage.
 

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your welome alfista
for what is worth ferrari treats some of their older v8s like 2 4cyls joined at a common crank that injects and ignites their v8 engines with seperate distributors and ecms for each bank of 4 that still allow the car to run on 4cyls! So go figure and keep us posted
 

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2 cycle engines with a dead or partially dead cylinder can gas-wash unburned oil film off liners quickly, with resulting piston scoring, usually on the skirts then moving up. Doesn't take long. 4 cycle engines takes longer. Outboard racing ("B" Hydro) in the early '60's I ruined a piston from a bad plug in my Mercury KG7H in about 5 minutes. Years later with my GTA engine, it began running as an intermittent 3 cylinder about half way into a race. Money (!) was at stake, so I continued, fearful that at any moment a massive failure might ruin-my-day. No podium finish, but I finished. Turned out one secondary choke retaining bolt had escaped the safety wire and disappeared. Replaced, the engine ran fine, no leak-down issue. Ran it the rest of the season without issue. Fall tear down showed no skirt damage whatever. NOW, this was a race engine, and not 100% representative of a street engine build.
I do not like to run any engine with a partially dead or completely dead cylinder unless I KNOW why. It's the "WHY?" that's critical. Sure, many issues result in -0- damage, but those that suffer damage, will be costly to fix. This is only my opinion from my own experiences.
 
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Discussion Starter #19
Thank you all. Car is at garage now. Did not drive it. Better be safe than sorry. Will post with news as they come in.
 

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As long as the tow or flatbed didn't do more damage than driving it 1 mile.
 
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