Pinto Misfire And Unleaded Markings On Head

[Guest Stuartl]

Hello All

 

I collected my Exmo yesterday and will shortly start to investigate the engine problem which is as follows:

 

From cold, the car starts fine then after about half an hour misfires and dies.

 

Re-starting results in misfiring/backfiring.

 

The previous owner did the following:

 

 

 

Changed the coil

 

Changed plugs, leads cap

 

Changed dizzy for a secondhand item

 

Replaced carb with a brand new one

 

Changed fuel pump

 

Changed fuel filters

 

Changed ignition module

 

Ran car without fuel filler cap on

 

All to no avail

 

 

I am wondering if there is something amiss with the cylinder head.

 

I asked the previous owner if he did a cold compression test and one after the misfiring started and he said he did with nothing untoward showing.

 

COULD it be that the cylinder head is not unleaded (it has been run on unleaded and no additives for at least the last six years) and valve seat recession could be causing this when the engine is hot?

 

I understand the markings that denote an unleaded head are near no 4 plug but I cant see anything. Has anyone got any pics of the position of these markings please?

 

Many Thanks in advance, Stuart

[chris n]

ID Code Engine Unleaded Head stamp

LC 1.6 Standard M, MM, N or NN

LS 1.6 Long stroke

(Similar to the 2.0 engine block) M, MM, N or NN

RE 1.8 S or SS

NE 2.0 Carburettor L, P, PP, R or RR

NR / N4 /205 2.0 Fuel injection L, P, PP, R or RR

 

 

 

HTH

[Guest Stuartl]

ID Code Engine Unleaded Head stamp

LC 1.6 Standard M, MM, N or NN

LS 1.6 Long stroke

(Similar to the 2.0 engine block) M, MM, N or NN

RE 1.8 S or SS

NE 2.0 Carburettor L, P, PP, R or RR

NR / N4 /205 2.0 Fuel injection L, P, PP, R or RR

 

 

 

HTH

 

Thanks Chris, I know the codes to look for but WHERE are they as I cant see them. I am either missing them or I have a Leaded Head!

[chris n]

They are on the flat side face at the rear of the head next to number 4 spark plug.

Is the engine a 205? this should be stamped on the block exhaust side

[chris n]

should be stamped here

[Guest djs dad]

had a similar problem on a motorbike i used to race years ago. turned out to be valve clearence way too tight. ok whilst cold but once warm/hot caused running problems and misfires.

may be way off the mark with your problems however.

[Guest Stuartl]

should be stamped here

 

Thanks Chris, that is great. I can confirm there are NO markings there at all.

 

I also cannot see a 205 stamp anywhere which I believe should be on the exhaust side underneath No.2 plug?

[Guest Stuartl]

had a similar problem on a motorbike i used to race years ago. turned out to be valve clearence way too tight. ok whilst cold but once warm/hot caused running problems and misfires.

may be way off the mark with your problems however.

 

This is my (probably wrong) theory about the valve seat recession causing the problem.

[Guest Stuartl]

The stamp on the side of the engine reads:

 

 

70HM6015BA

 

If I understand this correctly it refers to a November 1987 Engine which is before the heads became unleaded which seems to add up.

[chris n]

This is my (probably wrong) theory about the valve seat recession causing the problem.

 

We have had a few older Transits (campervans) in at work for MOT and not passing due to the CO2 being too high

All run fine but to rich, head off, valves out and relap the valves back in. New top end gasket set and they pass.

 

I would start by checking the valves clearence and go from there

[Guest Stuartl]

We have had a few older Transits (campervans) in at work for MOT and not passing due to the CO2 being too high

All run fine but to rich, head off, valves out and relap the valves back in. New top end gasket set and they pass.

 

I would start by checking the valves clearence and go from there

 

That sounds like good advice Chris, Thanks!

 

The engine sounds very sweet when started and if as I suspect the head is not an unleaded one I will try the valve clearances first then whip it off and get it machined for unleaded. I have a local chap who did work on my old crossflow engined Sylva Striker engine and he was very good.

[Longboarder]

I think you're barking up the wrong trees. Mechanical problem is not going to allow it to run sweetly for 30 minutes and then pants. Compression check also supports it not being mechanical. Predictable 30 minutes seems long for fuel so I would look electrical and start by swapping the coil for a known good one, then the amp. Brand new stuff can be faulty out of the box.

Another unleaded mark pic below. No such thing as an unleaded block and it's perfectly possible to have a leaded head on a 205 block and vice versa. All injection heads, with the cam lobe/pear shaped inlet ports are unleaded.

205 block, it's a casting mark, letters about one inch tall and proud of the surface cast into the side of the block.

 

Nigel

[Guest mower man]

For the time it takes first call would be valve clearances Ihave witnessed some v/strange probs with badly set /incorrect tappets inc some I did myself it,s a quick and no cost possible cure regards mower man

[Guest Stuartl]

Quote: "I think you're barking up the wrong trees. Mechanical problem is not going to allow it to run sweetly for 30 minutes and then pants."

 

Even if things start to close up once the engine is warm??

[Guest mower man]

Quote: "I think you're barking up the wrong trees. Mechanical problem is not going to allow it to run sweetly for 30 minutes and then pants."

 

Even if things start to close up once the engine is warm??

[/quot Stu see my post before your last the clue is in head off lap valves WHICH MEANS ADJUSTING VALVE CLEARANCES