Retitled: Gypsie's rebuild

[Gypsie]

I have been struggling with MPG for a bit now and have recently bought an LM1 to assist with fine tuning.

After having run a 200 mile trip and fine tuning the settings On Sunday I went to drive to the LL last eve and it wouldn't start.

Wouldnt even fire but once or twice in a half hour of trying. tailpipe smelled fuelly. Probly flooded but the plugs were dry.

I have been intending to check injectors for some time. First I tested the cold start valve. it was about 50* outside and when I checked to see if there was any flow (i.e. pull valve and hold rag over jet, crank engine). No flow whatsoever.
Bad Cold start think I.

Speak with Tristessa and he says it's too warm for the cold start to engage????

I thought it had to be 68* for the thermotime switch to tell the cold start not to operate (before the 11 seconds of run time expires).

I tested all the injectors on a bench and they are all opening when told to do so.

I have taken these in to Doctor Injector for cleaning and refurbishing. Seems like a good guy. Quick turnaround and not too spendy. first test showed one of the injectors with a slightly restricted flow. Left My dern CS on my bench so I will be bringing it in to him tomorrow. Doh!

All the injectors (except the CS) were soaked down pretty good when I removed them.

Any thoughts.

When I reinstall, I plan on testing all the power to them with special attention to the CS.

[spiffy]

Bad fuel mileage = mismatched deck height or compression ratio? Or maybe a sh*tty deck height (too large) or sh*tty CR (too low)? I am starting to think that my hot running/bad gas mileage issues with the 78 are due to one of the above because everything else I have checked/replaced/cleaned except for the assembly of the top end. The new engine cruises on the freeway at aboot 330-360 on the head temps AND it has 8.25:1 compression ratio.

[vwlover77]

I have been intending to check injectors for some time. First I tested the cold start valve. it was about 50* outside and when I checked to see if there was any flow (i.e. pull valve and hold rag over jet, crank engine). No flow whatsoever.
Bad Cold start think I.

Speak with Tristessa and he says it's too warm for the cold start to engage????

I thought it had to be 68* for the thermotime switch to tell the cold start not to operate (before the 11 seconds of run time expires).

The EFI book says that the thermo-time switch should operate the cold start valve for 3 to 7.5 seconds at 32 deg F and at "normal room temperature" (68 degrees?) it should operate for 1.5 to 4 seconds.

You should have gotten something from the CS valve with a cold engine at 50 degrees.

[Amskeptic]

tailpipe smelled fuelly. Any thoughts.

Fuel system sounds OK. How is your ignition system?
Colin

[Manfred]

What is your gas mileage?

[Gypsie]

13-14 at this point.


I have flipped the switch and determined that I am fairly close as it is with much of the topend removed. I will pull the engine and inspect deck height. This item was given 0 attention when I did the rings last year. This has been eating away at my psyche since i realized I should have considered this before omitting the head side rings.

Someone clue me in to how to get the compression ratio figgered.

I will also be able to thoroughly clean the HE's and do a proper torque job on the heads (what is it 30 overnight, back off then to 22 in the morning?) I'll look for the specs I read sometime back...

I may even have the heads refurbed.

I'm done fartin' around with this. 'nless someone has a better idea.

(Please have a better idea...)

[spiffy]

I used aircooled.nets cr calculator. Shoot for a deck height between .040 and.060 and then cc your heads to achieve the cr you want 8 to 1 will not make a grenade out of your engine but the cam comes into play when monkeying around with cr. The guy with the white cat would know what to do and could give you some solid advice.

I am going to rip into my top end as well because like you, I have put my hands on everything else. One cannot "tune" out a misconfigured top end.

[Gypsie]

Just got the injectors back. Withoug going into to much detail I will say that the flow went from 47-48 cc (for whatever time and pressure they tested at to 54cc across the board.

I recommend this Gentleman, Bob Evans (Doctor Injector) (610 1st st, gladstone, 503-513-5070)
.
$125 for the full meal deal for all 4 injectors and the CS. Quick turnaround (he wouldv'e done em while I stood there if I would have been willing to wait but I only had an hour lunch and 40 minutes was travel time). Nice guy and he still works for the little guy (like me) not just the dealers and shops. He thinks he did Jasan's recently. Is this correct?



Still going to do the deckheight thing so I can sleep again...

[Amskeptic]

I will pull the engine and inspect deck height. This item was given 0 attention when I did the rings last year. This has been eating away at my psyche since i realized I should have considered this before omitting the head side rings.

Someone clue me in to how to get the compression ratio figgered.

Sounds like a heart/lung transplant to get rid of a cough.

If you did a quicky overhaul last year, and did not throw in a totally different crank or discover caved in cylinder spigots in the case, the chances of your deck height being an issue are laughably small.
If you want to see if omitting the head sealing rings did anything to your compression, a compression test will tell you. If your compression figures are all in the 100-140 range, you are well within safe operation parameters. However, if you had the heads flycut, then it is possible that the heads are not sealing to the cylinders especially well, but you can see trouble easily enough under the car by taking off the lower tins and shining a bright flashlight up between the heads and the cylinders. There will be coked oil blackness along the bottom of the head at the cylinders, and it will explain any chronic stinky heat too.

What are your current compression test figures?
What is your current centrifugal timing at 3,200 RPM?
Does your vacuum advance *actually advance* to 40º when you blip the throttle?
What are the colors of your spark plugs?
Does the car coast to an imperceptible halt or does it stop sticky (dragging brakes will wreck fuel economy)?
Tires properly inflated?
Colin

[spiffy]

An engine with a wacked out top end can still have good compression. Even if you buy $700 heads from a "reputable" builder you better check yer numbers as said builder may have a different philosophy aboot top end set up that just doesn't jive with common internal combustion engine good sense. Not saying this is our friends diagnosis but all things being equal, checked, and working right one REALLY starts wondering what head CC's/deck height/CR is sitting under them heads if an otherwise healthy engine runs like a friggin pig.

[Amskeptic]

An engine with a wacked out top end can still have good compression. friggin pig.

Indeed, it's the too good compression I was looking for with the deleted sealing rings.

If he has consistently lousy < 90# comporession, well, that adds more information to the mix. Before he tears down the engine though, I think we ought to look at current tune-up parameters. A stuck upper distributor shaft would be a lousy reason to tear down an engine. Unless you are like me and want to dust the undersides of the cylinder deflectors . .

[Gypsie]

An engine with a wacked out top end can still have good compression. friggin pig.

If he has consistently lousy < 90# comporession, well, that adds more information to the mix.

Yes to both. my last comp tests were 95-97 for three and 105 for one.

I have not been able to get more than 17mpg with all sorts of adjustments and assuring.

I am more than halfway to pull having diaassembled the top end exhaust and HE's.

I will look closely at the conditions under the cylinders. It did have a burping type sound under accel/load. I seated the cylinders to the head with lap compound paste last summer. I did the tests over the past several months. double triple cheked valve adj (w/hyd. lifters, no less.).

still have not been able to improve and the compression test was not reassuring.

I did omit rings that were there when I disassembled for the first time. The heads looked new and I thought they may have been installed in error. Since I made such a huge presumption I am doing my penance by confirming one way or another. I am fortunate to have another vehicle to drive around while I settle the matter.

Just need to get my jack from Bob and out she comes.

I will report my findings.

[airkooledchris]

I have been struggling with MPG for a bit now and have recently bought an LM1 to assist with fine tuning.

After having run a 200 mile trip and fine tuning the settings On Sunday I went to drive to the LL last eve and it wouldn't start.

Wouldnt even fire but once or twice in a half hour of trying. tailpipe smelled fuelly. Probly flooded but the plugs were dry.

Let's back up, if there's still time to do so - what did you do when you were 'fine tuning the settings' over your 200 mile drive with the LM-1?


I have definitely seen issues with how my motor wants to start from cold based on changes I made to the AFM when it was good and warm and trying to hit those perfect numbers with the LM-1.

for me I got it where the motor seemed really really happy, idled like a kitten on amphetamines, 17:1 at less than 1/3rd throttle, 13:1 at WOT, idling around 900 rpm like nobody's business.
next day, gotta keep it floored just to start it, then gotta keep giving it gas so it doesn't die while I wait for it to warm up completely.

im not saying I solved my problem, as I haven't (still getting 12 mpg in town) - but just saying that if your chasing this ghost after making your changes, and IF you remember how far you went this way or that when adjusting the AFM, try putting it back where it was and see if you can get back to zero at least.

if nothing else do it so when you reinstall the motor you don't have to wonder if that's already going to be throwing you off.

[bus71]

Sealing rings would increase deck height, which would lower compression. 95 is ok but on the low side already. Low comp. decreases mpg(genereraly). just some thoughts.

[IFBwax]

What would high compression mean... around 140 or 150. Is that bad? Just curious.