L-jet AFM replaced, but the car won't stay running. (SOLVED) Options

[falcor75]

I have never seen those metal gaskets used before?

[malcolm2]

I have never seen those metal gaskets used before?

Could they be for Carb intakes?

[jtprettyman]

Perhaps you could borrow a known "good" AFM and swap it in- that will tell you more?

I have been offered one to test.... I hate the thought of BENDING someone else's $300 part.

I will go thru all the suggestions here by the weekend, I hope. They should remove all other doubt. Then check and see if the offer to loan is still good. And then I may have to breakout the checkbook on a freshly re-built, known good one.

Thanks again.

Clark -
Offer is still good to borrow mine, just keep in mind it is in the same uh, "patina'd" condition as my throttle body. Just let me know.

[McMark]

Just the phenolic block. The metal seals are indeed for carb motors (busses).

[malcolm2]

HEY HEY, I am back. Spent the last 2 weeks working on a VOLVO. Damn I hate that car.

Ok, I have gone thru my books... Haynes, Climer and Tom Wilson looking for intake runner torque settings.

Haynes said "4.35 lb f ft" on page 39. what the hell is that? My wrench is not gonna read that low if it is FT-LB.

Tom Wilson said 14 ft-lb on page 154 but that was in a table for type 1-3. just under that table are the torque settings for the type 4, but there is no mention of the intake manifold in the Tiv table.

Tom (page 153) also says "Use new gaskets on both sides, then lay the spacers on their studs. Using gasket sealer doesn't hurt, but isn't mandatory."

Is the gasket and the spacer the same? Climer has a nice exploded view drawing. #2 is the spacer, but there are no gaskets included. would both sides mean "of the engine" or both sides "of the spacer"?

Anyone use gasket sealer here? and where? on the head, on the top of the spacer, or both sides of the spacer?

What torque setting for #4?

[Dave_Darling]

The spacer should have paper on both sides of it. I remember the part coming with those already glued to it.

Torque for an M6 bolt into aluminum is on the order of 10 lb-ft. Use anything between 5 and 10, or just get it "a bit tight."

--DD

[malcolm2]

These are Victor-Rienz. Looks like paper on each side. Tuff to tell. The edges are shiny and i see what looks like glue on the edge. the mating surfaces are not shiny, probably paper.

On the torque, i figured i'd compare intake to exhaust, which would be a bolt. The intake is a nut on a stud. Seems to me that setup might handle more since the stud is not being torqued.

May be opposite tho.

[malcolm2]

Morning (IMG:style_emoticons/default/icon_bump.gif)

[Rob-O]

So I've been fighting with a very similar problem with my L-Jet. For months....

However, I had just installed my L-Jet after removing the single carb setup. Almost everything was checked before being installed on the car (more on that later) or new (i.e. vacuum hoses, dual relay, TB rebuilt, etc.). I timed the car (multiple times) and installed a Pertronix.

I checked and rechecked everything, including the CHT. The resistance readings on the CHT were very close to expect4ed values published on the 'net (I checked it installed on the car, so it was difficult to get the readings at the exact temperatures that are called out for the CHT).

My symptoms were similar to yours, although not exactly the same. My car idled poorly and ran poorly. In checking the CHT, if I unplugged it from the harness while the car was running, the engine died. It started right up again when I plugged the CHT back in. I thought vacuum leak as well so put clamps around any of the new hoses that weren't on their respective parts as tight as I thought they should be. This included anything downstream of the AFM. As in, the hookup of the AAV to the plenum and the line that runs from the large rubber elbow to the oil fill housing. The small metal sleeve on the rubber elbow between the AFM and TB was pulled out and I could never get it back in. But even when I pulled the hose off the elbow and plugged the hole I still had poor running/driving. Last week I even purchased a new elbow from 914Rubber (it is awesome, BTW). Installing it didn't help. I also had purchased a new CHT from 914Rubber. I tried to pull the old CHT out of the head and had trouble doing that. It unscrewed about a turn and a half and then stops. But then I got the bright idea that the CHT is using the head as a ground and that if I grounded the new CHT and hooked it up to the FI harness, it should be getting the same reading as if it was hooked up to the engine when the engine is cold. I did that little experiment. Car started right up and idea was rock steady at 1000 rpm. I adjusted down to 850 or so. Took it for a very short drive and the car runs 90% better. Didn't want to go too far with the CHT just sitting in the engine bay getting erroneous temperature readings and using those readings to richen or lean out the mixture.

I had opened my AFM cap as well and marked the position of the spring. I adjusted it tighter and looser and neither had an effect. Probably shouldn't have opened the cap to begin with.

So, I know that's a long story, but my point is, after you get your vacuum leak project completed, check your CHT. As cheap as they are at 914Rubber you might want to pick one up anyways. Just to have one on hand. You could always do what I did, just ground it securely to something in the engine bay and plug it into the harness. You should also check to see that your current one is plugged in securely. If it isn't, that would cause a whole host of problems similar to what you're experiencing. Ask Clay, he had this issue awhile back where it took him a week or so to realize that the CHT was making a poor connection and causing poor running. If I remember correctly, it turned out that the CHT, while plugged into the small plastic sleeve, wasn't actually plugged into the male spade inside the sleeve.

According to the Anders site on D-Jet, the CHT plays a huge role in the fuel enrichment circuit. I assume that the CHT plays a similarly large role in the L-Jet system.

Sorry for the long rambling post!!!!!

[Rob-O]

These are Victor-Rienz. Looks like paper on each side. Tuff to tell. The edges are shiny and i see what looks like glue on the edge. the mating surfaces are not shiny, probably paper.

On the torque, i figured i'd compare intake to exhaust, which would be a bolt. The intake is a nut on a stud. Seems to me that setup might handle more since the stud is not being torqued.

May be opposite tho.

I don't remember what I torqued mine to. Actually I don't think I torqued them. I just got them tight. But in reading some posts on the subject, it was mentioned (RTowle?) that he used a small amount of orange high-temp sealant on each side of the phenolic spacer/gasket. I did the same and I don't think there are any leaks there.

[malcolm2]

Sometime in the last few months, I installed the 914rubber TS2. Prior to that I ran the "INSTALLED" green line unit.... for about 3 years. The other line on this graph is from Ratwell's website as a comparison.

So the unit that made the RED line is currently in the car. I have not checked it since my AFM warped. My problem with the green line unit, was start-up idle or cold idle. The car needed my foot to stay idling at 950-ish until I got to 300*F CHT. Looking at the graph, it seems that the 914rubber unit would help. But I really did not see a difference.

BTW Thanks for the info about your test. And I also have a new 914 rubber 1975 version of the elbow with 2 large accessory outlets.



Soak your stuck sensor overnite in PB Blaster, or Sili-Kroil or WD-40 to break it loose.

I am glad to hear someone else has tried the gasket sealer, I have some and will give it a shot. I found a few more sites with FT-LB recommendations... crazy tho, some say 4 ft-lbs some say 18 ft-lbs. I think I will go with 10.

THEGOLDENBUG.COM
Torque Wrench settings
Injector/Manifold bolts to cylinder head
Lb Ft 4
Nm 5.4
mkg 0.6

TORKSPEC.COM
Intake Manifold To Cylinder Head Multi Port Fuel Injection
18 Ft-Lbs
216 In-Lbs
24.4 N-m

Intake Manifold To Cylinder Head Single Point Injection

7 Ft-Lbs
84 In-Lbs
9.49 N-m

[timothy_nd28]

You forgot to add the units to your graph (IMG:style_emoticons/default/biggrin.gif)

[Rob-O]

You forgot to add the units to your graph (IMG:style_emoticons/default/biggrin.gif)

He did, but the title of the graph should help out there...

Only one axis can be temperature and the other axis resistance. (IMG:style_emoticons/default/biggrin.gif)

[malcolm2]

You forgot to add the units to your graph (IMG:style_emoticons/default/biggrin.gif)

I figured the title would do. I never really planned on showing anyone and I know what the units are. (IMG:style_emoticons/default/blink.gif)

[malcolm2]

And now back to the subject....

This is the 1/2 side. Bottom of the intake runners. so the black stuff would be under the pipes close to the head.

Would this be considered a leak?

[Rob-O]

I would think so. Looks sooty to me but I'm not sure I would believe that much soot would be coming out of the intake area...even with the backfiring you had going on.

[timothy_nd28]

I think Clark did something sneaky by quickly adding that subtitle, I never saw that before (IMG:style_emoticons/default/bye1.gif)

The great Captain Krusty may roll in his grave as I get ready to say this, go ahead and RTV the shit out of that gasket. Your previous threads asked the community why certain cylinders were running hotter than others. A vacuum leak will cause this, and as you have learned, a vacuum leak will also cause our Ljet's to backfire and kill the airflow meter.

I don't think you need a torque wrench for the 4 nuts on the intake manifold, just use your best judgement. Keep in mind that the steel studs are screwed into aluminum, which will strip.

[malcolm2]

Gracias Timothy,

Adding that graph was not easy, 1st I had to boil water, make a rig to hang the TS2 in the water ( need to use cooking oil next time), get a thermometer, take the measurements and make the graph. (IMG:style_emoticons/default/happy11.gif)

then figure out how to save it as JPG. then make it small enough for this forum. I wish we could just copy and paste into this forum and the screen shot would be there.....and be the right size, facebook figured it out, why can't we?

anyway, I was heading in your direction Tim, but I will at least check the torque once I get a warm and fuzzy with my tightening.

I thought I had the right gasket maker, but I don't have any that will handle over 300. So I am off to the store.

I have been looking at lots of pix of vw engines online. It seems that lots of them use hose clamps on the little intake hoses. I got new ones, but I am gonna clamp them too.

During disassembly, I found lots of oily-gassy, wet spots around and under areas where stuff connects. kinda like the sooty picture above. Damn I have vacuum leaks.

Clark

[malcolm2]

As luck would have it, I got everything back together and the fuel pump is not starting up. I have 0 psi on my engine bay fuel gauge shown in previous posts.

UPDATE. bent my AFM. Got a used 7 pin one that matches, Car would start but would not idle or even run well. Air leaks seemed to be the problem.

I removed the intake tubes on both sides and found a broken spacer/seal. To remove the tubes, most of the FI stuff needed to be unplugged on the passenger side.... ECU, DUal relay, the resistor pack, the coil. And of course the FI and fuel lines were moved.

Right side needed the airbox and intake elbow removed. along with the Injectors.

OK, i got new intake spacers added 600*F RTV to both sides, new FI seals, new air distributor hoses and added hose clamps to those little hoses. Already had a new intake elbow.

Put it all back together and the starter fires, but no fuel pressure. With the key on I can open the AFM and move it and I hear what I assume is the dual relay clicking, but no fuel pump.

[malcolm2]

BROKEN WIRE.... I decided to retrace my steps and found this wire on the ignition side of the dual relay had broken. Luckily I did have some of that type of connectors with the tab to insert into the block.

once fuel pressure built up the car started..... problem is still there. Ruff starting and even ruff running. I can hold the pedal at about 2500 rpm for 4 seconds, then the car starts to die on it's own.

I think I am back to the culprit being the USED and unknown condition AFM I bought for $150, I think it was. Well at least that is what some of the core charges were on freshly rebuilt ones.

Back to the drawing board.