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90's EJ20 questions...


DQ81
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Hello all

 

I've recently put an EJ20 in my 72 VW Beetle. I thought I had a few questions but it seems to be quite a few!

 

It's a great runner although the gas mileage around town seems like it could be better.

 

about 8km to to the liter in an 800kg car. Should it be better as the car is lighter? I do run higher RPM's than in a Legacy though, so perhaps that evens out...

 

Also I have some plumbing questions.

 

There's a tube coming off the throttle body that has no hose on it, doesn't seem to be hurting anything just wondering what it is....

 

I was hoping for a picture of a legacy engine from the firewall side...

 

I also don't have a knock senor, but my harness does have the provision for it, any harm here? Pro's cons?

 

Where can I find the exact engine code (to the right of the intake on the rear of the engine standing in front of it?) if I have that number can I identify the exact engine type and what it came out of?

 

Also having an issue with a VERY stubborn air pocket getting stuck just at the CTS, it's pegged my aftermarket gauge a few times but the coolant itself is about 80 celcius but the gauge reads up to 125 celcius. Keep it at 3-4k Rpm for about 40 seconds and it pushes through and drops to a nice 80-85 celcius....very frustrating. If turn the engine off for over 30 seconds the air seems to get trapped there again as it's a higher point and at the very end of the cycle thus getting the least amount of push as it's just in front of the waterpump...

 

Anyone have values for the CTS (ohms)?

 

Values for the gas gauge in ohms? (i'm using the Suby pump and want to match to Beetle gauge)

 

Starts great cold and hot, runs well, no black smoke indicating a rich condition.

 

It has about 300k kilometers on it and is still running strong. Just want to be informed and keep my engine in the best shape it can be.

 

Any ideas on getting that stubborn pocket out? Keep in mind that I'm running coolant lines front to back on the beetle with the radiator up front so that's quite a bit of coolant for the pump to push...

 

What weight oil do these engines like? I'm running a pretty open exhaust, is lack of backpressure an isseu?

 

Thanks in advance and hope to gain some knowledge here! Love these Suby's!

 

A video of my bug, gotta make a better one, this was the day the exhaust was made just wanted to hear how it sounded:

 

Edited by Legacy777
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Welcome to the USMB.

 

I added a link for the video and moved your thread over to the transplant forum. It may get some additional comments here.

 

 

It's a great runner although the gas mileage around town seems like it could be better.

 

about 8km to to the liter in an 800kg car. Should it be better as the car is lighter? I do run higher RPM's than in a Legacy though, so perhaps that evens out...

 

If I did the math right, that's about 18-19 mpg. That's not horrible, but I agree, that's not great for how light the beetle is.

 

 

Also I have some plumbing questions.

 

There's a tube coming off the throttle body that has no hose on it, doesn't seem to be hurting anything just wondering what it is....

 

I was hoping for a picture of a legacy engine from the firewall side...

 

That tube is probably for the canister purge valve. It's for emissions purposes. You can just plug that tube. Is it this tube?

 

http://main.experiencetherave.com/subaru/images/TB/DCP_1511.JPG

 

 

I also don't have a knock senor, but my harness does have the provision for it, any harm here? Pro's cons?

 

What are you running for engine management? The stock computer? You need to have knock sensor hooked up. If you are running the stock computer and don't have the knock sensor hooked up, that is probably one of the reasons you're getting poor gas mileage. The ECU will retard timing to avoid any chance of detonation. This will hurt gas mileage and will cause you to lose power.

 

Do you have the check engine light hooked up? If not, I'd suggest wiring a bulb to that pin on the ECU, and then checking the ECU for stored codes to see what's in there that could be giving you issues. Any more info you can provide about your setup will help in diagnosing.

 

 

Where can I find the exact engine code (to the right of the intake on the rear of the engine standing in front of it?) if I have that number can I identify the exact engine type and what it came out of?

 

Is it sticker on the engine or in the casting?

 

 

Also having an issue with a VERY stubborn air pocket getting stuck just at the CTS, it's pegged my aftermarket gauge a few times but the coolant itself is about 80 celcius but the gauge reads up to 125 celcius. Keep it at 3-4k Rpm for about 40 seconds and it pushes through and drops to a nice 80-85 celcius....very frustrating. If turn the engine off for over 30 seconds the air seems to get trapped there again as it's a higher point and at the very end of the cycle thus getting the least amount of push as it's just in front of the waterpump...

 

It sounds like the water pump isn't able to keep the required flow moving through the system and it's stagnating at that high point. How much additional hose did you add to run the radiator in the front? What size hose?

 

Depending on what you have setup, you may have to put some sort of electrical booster pump in-line to keep the system from stagnating at idle.

 

 

Anyone have values for the CTS (ohms)?

 

Values for the gas gauge in ohms? (i'm using the Suby pump and want to match to Beetle gauge)

 

I don't have them off the top of my head now, but do have some documentation at home. The CTS uses a standard Bosch NTC calibration curve. I'll try and get you the gas gauge and CTS info when I get home.

 

 

What weight oil do these engines like? I'm running a pretty open exhaust, is lack of backpressure an isseu?

 

I run 10w30. With miles that are on it, I'd probably stick with 10w30 or 10w40. The lack of backpressure shouldn't be an issue.

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Welcome to the USMB.

 

I added a link for the video and moved your thread over to the transplant forum. It may get some additional comments here.

 

Thanks, sorry about that. Just a bit excited to get all the info down! Let's hope so.

 

 

 

If I did the math right, that's about 18-19 mpg. That's not horrible, but I agree, that's not great for how light the beetle is.

 

That's right on. Exactly as you said, not horrible but not great considering the Beetles weight. I have gotten as high as 35mpg on a straight 20 mile highway cruise but that was 4k rpm constant, an ideal way to get great mileage. I have talked to a guy who had an EJ20 in his Beetle who got exceedingly better mileage around town...

 

 

 

 

tube is probably for the canister purge valve. It's for emissions purposes. You can just plug that tube. Is it this tube?

 

http://main.experiencetherave.com/subaru/images/TB/DCP_1511.JPG

 

Actually that isn't it. It's a bigger diameter, proably 10mm/ or 1/4" to 3/8"

and it's directly off the side, I'll take a picture of it.

 

That pic does raise another question I have. The Suby throttle body has 2 linkages on it...does it matter which one I use and which one is for what?

 

 

 

What are you running for engine management? The stock computer? You need to have knock sensor hooked up. If you are running the stock computer and don't have the knock sensor hooked up, that is probably one of the reasons you're getting poor gas mileage. The ECU will retard timing to avoid any chance of detonation. This will hurt gas mileage and will cause you to lose power.

 

Do you have the check engine light hooked up? If not, I'd suggest wiring a bulb to that pin on the ECU, and then checking the ECU for stored codes to see what's in there that could be giving you issues. Any more info you can provide about your setup will help in diagnosing.

 

Stock Subaru ECU with custom wiring harness (basically stripped down to engine managment)

 

I came across your site by way of a different forum and was just looking over the ECU read out tech article. I'll be hooking up a check engine light asap for diagnostics.

 

The knock sensor would be located behind the intake on the drivers side of the engine in front of the intake right? I'll have to double check if it's hooked up, I know I have an extra wire in my harness that isn't hooked up...

 

 

Is it sticker on the engine or in the casting?

 

I haven't looked yet as it's tight against the firewall in the Beetle. I believe it cast. And for ECU read out purposes I need to know what year this engine is. I know I have the two green plugs and 1 black one, so I'm thinking it's a 94/93

 

Can you refer me to a good source to make sense of the casting number?

 

 

 

It sounds like the water pump isn't able to keep the required flow moving through the system and it's stagnating at that high point. How much additional hose did you add to run the radiator in the front? What size hose?

 

Depending on what you have setup, you may have to put some sort of electrical booster pump in-line to keep the system from stagnating at idle.

 

I have the radiator up front with aprox 14ft of 40mm hoses going back and forth in total.

 

I changed the thermostat yesterday to a 79c and took out the pin that sits in the bleedthru hole. Bled it by putting the nose up and car at a 45* angle. Seems to have worked so far and I have a much better flow at idle.

 

I haven't had a chance to do some realworld testing as the EJ20 has developed a driveability issue.

 

Bog under load, say high gear low RPM or WOT acceleration. So on a flat road at 1200 rpm in gear, no matter what gear, if I try to accelerate hard it shakes/bogs/sputters/missfires, if I let off the throttle and accelerate gently it's either less violent or smooth.

 

It starts a little hard but nothing dramatic for an engine with 300k kilometers, idles fine (every so often once warm shifts 30 to 50rpm sporadically). Off idle if I blip the throttle I can hear it missfire slightly, sounds like a missfire, could be a bit of a bog etc. Gradual acceleration is silky smooth.

 

It's not constant, it does this 3/4 of the time, every so often it will be fine and it just started doing this 3 days ago (symptoms were present before changing thermostat).

 

I was thinking of checking the CTS, TPS and then the ECU for codes first. Perhaps wiping the ECU because it thinks the engine has overheated frequently the past 60 miles (with the trapped airpocket reaching temps of over 120c) and I read a post somewhere that an EJ25 ran like crap after overheat and fine after resetting the ECU.

 

I was also thinking the CTS might be fried, literally from that stupid airpocket. Or that the TPS has gotten dodgy, although it is smooth at higher RPM, or if throttle is applied slowly.

 

Last thoughts are fuel pump or pressure regulator, what should the fuel pressure be and where is the regulator?

 

What is the most likely culprit in your opinion?

 

I don't have them off the top of my head now, but do have some documentation at home. The CTS uses a standard Bosch NTC calibration curve. I'll try and get you the gas gauge and CTS info when I get home.

 

Sweet, thanks I apreciate that! This way I can get a gas gauge working and rule some things out, if you could be so kind as to look up the TPS and cam sensor values that would be great.

 

 

I run 10w30. With miles that are on it, I'd probably stick with 10w30 or 10w40. The lack of backpressure shouldn't be an issue.

 

Allright man thanks, I was running a mineral 10/40 but might go to 10/30 as I do rev the hell out of it if I'm honest.

 

BTW, one final question. I can get my hands on a EJ22 with half the mileage and 20 extra horses are well felt in a Beetle. Is this just a strocked EJ20 or does it have a bigger bore? I wanna get the EJ20 running well either way because I'll still use it, just curious about the EJ22, ECU and wiring all the same?

 

Thanks A LOT for your help so far man!

Edited by DQ81
another Q
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Bog under load, say high gear low RPM or WOT acceleration. So on a flat road at 1200 rpm in gear, no matter what gear, if I try to accelerate hard it shakes/bogs/sputters/missfires, if I let off the throttle and accelerate gently it's either less violent or smooth.

 

It starts a little hard but nothing dramatic for an engine with 300k kilometers, idles fine (every so often once warm shifts 30 to 50rpm sporadically). Off idle if I blip the throttle I can hear it missfire slightly, sounds like a missfire, could be a bit of a bog etc. Gradual acceleration is silky smooth.

 

It's not constant, it does this 3/4 of the time, every so often it will be fine and it just started doing this 3 days ago (symptoms were present before changing thermostat).

 

Spark plugs or Plug wires. Coupled with lack of knock sensor

 

 

 

BTW, one final question. I can get my hands on a EJ22 with half the mileage and 20 extra horses are well felt in a Beetle. Is this just a strocked EJ20 or does it have a bigger bore? I wanna get the EJ20 running well either way because I'll still use it, just curious about the EJ22, ECU and wiring all the same?

 

 

The pistons are a larger diameter. The casting and the liner are larger diameter. It's not really a larger bore of the same block, but a larger cast cylinder. You could not bore an EJ20 to the size of EJ22 pistons.

 

That said, they are physically the same external dimensions. As long as the EJ20 is a SOHC, you should be able to bolt an EJ22 right in with the same intake and wiring.

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The pistons are a larger diameter. The casting and the liner are larger diameter. It's not really a larger bore of the same block, but a larger cast cylinder. You could not bore an EJ20 to the size of EJ22 pistons.

 

That said, they are physically the same external dimensions. As long as the EJ20 is a SOHC, you should be able to bolt an EJ22 right in with the same intake and wiring.

 

Cool, I'll keep that in mind. Thought as much, good to hear conformation. What about ECU and MAF interchangeability? I have a few spare ECU's/MAF's for the EJ20...

 

I'm assuming exhaust etc. is also the same.

 

 

Spark plugs or Plug wires. Coupled with lack of knock sensor

 

I'd thought of this but the wires and plugs are less than 5k miles old, it's always possible. And it's functioned just fine for the last 10k miles without the knock sensor hooked up...

 

 

Any other thoughts?

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I'd thought of this but the wires and plugs are less than 5k miles old, it's always possible. And it's functioned just fine for the last 10k miles without the knock sensor hooked up...

 

 

Any other thoughts?

 

Seems like it was the number 4 plug wire had come loose while I had been checking vacuum hoses that day... we'll see if this holds up.

 

My knock sensor isn't hooked up.

 

With everything else in good mechanical order. What detriment will the lack of knock sensor have?

 

It retards timing as a default without it so I slight lack of performance and gas mileage is to be expected?

 

I have the stamped engine code off the motor and am wondering if anyone can help me identify the year.

 

I tried to read for codes but the check engine light wire from the ECU gives a max of 0.6 volts when the IGN is put to ON and does read anything after the engine is started.

 

I also only have the two Green wires and only one black terminal.

 

I need to know if I have a pre or post 94 engine for future reference.

 

It's an EJ20 as stamped in the front of the block I also found "62" stamped on the passenger front side.

 

The more important enginen number stamped on a pad next to the throttle body on the drivers side is:

 

470633

 

Any help? Google yielded only WRX and Sti stuff...

 

EDIT:

 

From what I can find so far, the 91-93 Subaur Legacy EJ20's DIDN't come from the factory with a knock sensor, they cam with the wiring and provision for it, but no Knock sensor. Can this be right?

 

Would this have been a quick fix to bring emissions down?

Edited by DQ81
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I'm not an expert, but I may be able to answer two of your questions...

 

I tried to read for codes but the check engine light wire from the ECU gives a max of 0.6 volts when the IGN is put to ON and does read anything after the engine is started.

--> You might be checking voltage to a 12 volt positive? Check engine light from ECU is 12v, must put through light to ground to work. Try checking volatge to ground in test mode (black connectors hooked up), it should come on, then flash trouble codes. A test light works perfectly for this. Even if no trouble codes, it should come on when in test mode.

 

I also only have the two Green wires and only one black terminal.

--> Do you mean two green plugs and one black plug?? One of the green plugs should be a ground (black and a colored stripe (cannot remember the color)) and if you can fit the black plug in there it will work as it should. Subaru has these two plugs wired to the same ground wire. If you can't figure that out just run a jumper from black plug to ground for test mode.

 

-->That's all I can help with, like I say , I'm no expert myself.

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I'm not an expert, but I may be able to answer two of your questions...

 

I tried to read for codes but the check engine light wire from the ECU gives a max of 0.6 volts when the IGN is put to ON and does read anything after the engine is started.

--> You might be checking voltage to a 12 volt positive? Check engine light from ECU is 12v, must put through light to ground to work. Try checking volatge to ground in test mode (black connectors hooked up), it should come on, then flash trouble codes. A test light works perfectly for this. Even if no trouble codes, it should come on when in test mode.

 

I also only have the two Green wires and only one black terminal.

--> Do you mean two green plugs and one black plug?? One of the green plugs should be a ground (black and a colored stripe (cannot remember the color)) and if you can fit the black plug in there it will work as it should. Subaru has these two plugs wired to the same ground wire. If you can't figure that out just run a jumper from black plug to ground for test mode.

 

-->That's all I can help with, like I say , I'm no expert myself.

 

Thanks, that's very helpfull actually, as I only had the + side of the two black terminals. Now I know I can just ground that and should get any readings off the Check Engine light. Does this light not usually cycle on when you turn the ignition on though? It doesn't even give me 12v then, just the 0.6v using a multimeter with the + on the check engine wire and the - grounded.

 

I got a knock sensor today, hooked it up. Yet to see what the difference is as by the time all was said and done I had to go home and leave the Bugaru behind.

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Legacy777 how about hittin me back with those values!?

 

Here's a few pics, maybe that will inspire some more responses?

 

EJ20 fresh outta the Legacy:

 

19671.jpg

 

Beetle transmission mounts getting beefed up for EJ20 fitment:

 

300520091121.jpg

 

Engine in the Beetle, this was a test fit, it's been followed up by some cleaning and propper fitment of the overflow etc.

 

IMG_0506.jpg

 

Then fitted a later style rear decklid etc.

 

IMG_0505.jpg

 

It became time for inspection so I did a quick rattle can respray of the rear decklid and fitted older style lights. I don't have pics yet but have fabbed an exhaust that replicates the orgional Beetle exhaust and gives a boxery sound

 

IMG_0514.jpg

 

Have the radiator mounted up front.

 

The whole car looks like a regular Beetle with the apropriate Suby power under the hood.

 

Here's a vid taken on the fly this is with the Beetle style exhaust, gives a little more low end in person. I intend to get some higher quality vids up on youtube soon. But it's great fun for a Beetle.

 

Edited by DQ81
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You need to supply 12v to the CEL output on the ECU. Circuits always sink power better than supplying power. With the test meter, put one side on the CEL pin, and the other side to a 12v source.

 

Even if there are no codes stored it will blink at a steady rate.

 

All the codes can be found on my site.

 

http://www.surrealmirage.com/subaru/engine.html

 

 

I'll try and work on getting the values tonight. Been busy....

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You need to supply 12v to the CEL output on the ECU. Circuits always sink power better than supplying power. With the test meter, put one side on the CEL pin, and the other side to a 12v source.

 

Even if there are no codes stored it will blink at a steady rate.

 

All the codes can be found on my site.

 

http://www.surrealmirage.com/subaru/engine.html

 

 

I'll try and work on getting the values tonight. Been busy....

 

no worries man, thanks for letting me know you haven't forgot, sometimes threads just die, I like to see them through...

 

I'll see e'm when you have time,

 

David

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Here's resistance values for the (2-wire) engine coolant temp sensor

 

2.0 - 3.0 kohms @ 20 deg C (68 deg F)

0.3 - 0.4 kohms @ 80 deg C (176 deg F)

 

 

Here's the resistance values for the (1-wire) dash gauge sensor

 

187.6 ohms @ engine coolant temp 46 - 54 deg C (115 - 129 deg F)

19 ohms @ engine coolant temp 116 - 124 deg C (241 - 255 deg F)

 

Here's a scan from the factory manual on the dash gauge.

 

http://www.main.experiencetherave.com/subaru_manual_scans/FSM_Scans/1992_TLegacy_Dash_Temp_Diag_non-USDM.zip

 

 

Here's the fuel gauge info I have. Similar to what ts39136 posted.

 

E - 92 ohms

1/2 - 48.5 ohms

F - 5 ohms

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That pic does raise another question I have. The Suby throttle body has 2 linkages on it...does it matter which one I use and which one is for what?

 

It shouldn't matter. The outer cam is typically setup for the throttle linkage and the inner cam is setup for the cruise linkange. The inner cam is slightly smaller and may give a little more resistance over the outer larger cam.

 

 

 

The knock sensor would be located behind the intake on the drivers side of the engine in front of the intake right? I'll have to double check if it's hooked up, I know I have an extra wire in my harness that isn't hooked up...

 

The knock sensor should be just straight down if you're looking at the throttle cables. Here's a pic of the knock sensor.

 

http://www.main.experiencetherave.com/subaru/images/injectors/DCP_2481.JPG

http://www.main.experiencetherave.com/subaru/images/injectors/DCP_2475.JPG

 

 

Not sure if I answered all your questions. If not, let us know.

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