FI Hard Starting/Poor Idle/Won't Run

[zekow1]

I found an old triumph mecanic now working on Jags.

He concluded ( without seen it )to look at the short block or the head, He says that 100 to 110 PSI is a minimun and not good enough
His instructions after Listening to me blab about all I've done ,was:

Take a little oil place it inside the piston check Compression one by one.
If the Compression is better (you guys know right!!!!!)piston rings etc etc etc.

If it stays the same then its the head( and you guys know what that means take it back to the rebuilder and fix)
In his eyes it pretty much caput.
His Right Isn’t he??

It's Running

[Stag76]

If it's a North American engine with 8.00:1 compression ratio, 110 psi is OK, and 100 is a little bit low. An 8.00:1 ratio is approximately 120psi if everything is perfect, but, with an engine that hasn't been running for some time there may be a little valve or ring leakage, or the compression gauge may not seal perfectly or read exactly etc. You could do the test, but I think that engine should run OK on 100-110psi.

TR7 Convertible
Sprint Motor
MegaSquirt EFI

[jbsjim]

I agree. They were pretty even and that's a good sign. Mine run about 120 with a slightly shaved head. Do the spoonful of oil test - it's always better to know. A leak down test will also let you know where pressure is escaping the cylinder (valves or rings). I don't think that's what we've been chasing here.

[IMG]

[zekow1]

I will do the test but its great to hear that it ok at that pressure .
He's then mistaken, he was expecting 135 to 140 .
I will do the test and i will probably end up taking the head out and placing that thick gasket .
I should have placed it after doing the head anyway.

It's Running

[Stag76]

135-140psi would be for the 9.25:1 pistons. Are you going to use a standard or a thick gasket. There's very little difference in the compression ratio, and the thick gasket is only used if the head has been skimmed so the thickness of the head is less than 112.4 mm or 4.427 inches.

You measure the head height (using vernier calipers) from the bottom of the half moon shaped cutout on the end of the head to the head surface. The minimum head height for use with a standard gasket is 112.4 mm or 4.427 inches. Valve-piston clearance on North American engines with 8.00:1 pistons is not a problem, so, if the valve timing is close, there is really no need to use the thicker gasket.



TR7 Convertible
Sprint Motor
MegaSquirt EFI

[wedgewa]

This is a great thread with lots of useful info. One thing I didn't spot was what I encountered when waking up my 1980 injected TR7 after 11 years of sitting in my garage.
Old gas.
Even the professional shop I use was reluctant to pull the tank until the injectors had been sent out for cleaning 3 times. (Apparently in a carb car it's possible to burn through old gas.) But the final solution to the symptoms I had (similar to those described here) was to send the gas tank out for deep cleaning and relining. Plus new gauge sender, fuel pump and filter. And one more injector cleaning.
One of my clues was that the catalytic converter would get hot enough to glow red in the dark when the engine was stumbling badly.

The guy who was selling NOS Delco distributors on ebay ran out some time ago. I did have a problem with my original before the 11-year hibernation and back in the early 90's was then only able to find a NOS Canadian spec replacement. Slightly different advance/retard but continues to run fine and passed Washington emissions with no problem.

[RadioGuy]

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">135-140psi would be for the 9.25:1 pistons.<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

Hummm, Mine...at least two cylinders, are 150 and 160. Wonder what the compression ratio is...(idle thought)

Sadly the front two are 130 and 140....Yea, I know, that's why it's parked right now, need to do the leak down test, see where the sound is coming from and then pull the head and do the head job. I hope the block is not damaged between the cylinders...[:(]

Hopefully it's just the head gasket.

Ken


Maintained on Saturday…Drive on Fun-Day !!! 1976 FHC - 1980 DHC

[iedkwok]

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by zekow1</i>

iedkwok
First welcome to our forum.
Is your car running?
If it is ?
Is it running well?

If not then tell us what is happening and we will help you throught it.
Now ,If your intentions are to rebuild ??
Then, The Plenum chamber is held on by two brakets on the bottom of the plenum chamber.
One is connected to the block
The other is connected to the motor mount .

The four big hoses that are connect from the chamber to the manifold are also supporting it.Loosen the four clamps on the chambers side.

On the side by the fire wall there are three bolts ,take them out and take the whole throttle cable assembly out and put it on the side.

disconnect the throttle switch on the side of the throttle body
Disconect the switch these are two small cables.
Disconnect the cold start valve it will be on the bottom middle of the chamber.

and now for the pieze of recistancceeee.
loosen the clamp on the lower part of the throddle body

Now care fully , CARE FULLY pull up and towards you .

it sound much easier than it is
the chamber is usually stuck to the four hoses on the manifold.

[:D]



It's Alive


<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

[iedkwok]

No the car is not running, and it would turn over, but wouldn't start. I have read something about "mass air meter flap" and using a screw driver to wedge open so air could flow through. Where is the Mass aire meter flap locate? I also knew I should replace all air hoses, but think I will need to remove the plenum chamber so I will try to follow the direction below...
Since last March, I have removed the vacuum retard, because the unit didn't pass the vacuum hand pump test. but I was told that I don't need to have a vacuum retard unit install and the car should still runs. The vacuum retard unit is connected to the distributor housing and lached on to the inner ignition of the distributor. The other end of the vacuum retard is connected to the plenum chamber.
//iedkwok
<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by zekow1</i>

iedkwok
First welcome to our forum.
Is your car running?
If it is ?
Is it running well?

If not then tell us what is happening and we will help you throught it.
Now ,If your intentions are to rebuild ??
Then, The Plenum chamber is held on by two brakets on the bottom of the plenum chamber.
One is connected to the block
The other is connected to the motor mount .

The four big hoses that are connect from the chamber to the manifold are also supporting it.Loosen the four clamps on the chambers side.

On the side by the fire wall there are three bolts ,take them out and take the whole throttle cable assembly out and put it on the side.

disconnect the throttle switch on the side of the throttle body
Disconect the switch these are two small cables.
Disconnect the cold start valve it will be on the bottom middle of the chamber.

and now for the pieze of recistancceeee.
loosen the clamp on the lower part of the throddle body

Now care fully , CARE FULLY pull up and towards you .

it sound much easier than it is
the chamber is usually stuck to the four hoses on the manifold.

[:D]



It's Alive


<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

[jbsjim]

The air flow meter is on the passenger side of the engine bay directly behind the stock square air cleaner. On the picture of my car below it is seen with my K&N cone air filter attached directly to it.
Jim

[Workshop Help]

Bump.