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Help and Advice for a L26 w/ 240 SUs


Buma

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I have some trouble. I'm pretty new to all this and would rather ask you guys for advice then to continue on my own.

 

My car has 38k or 138k miles on it (prob 130k). Someone has put 240 carbs on it, but I'm not sure if they have rebuilt the head (w/ hardened seats or unleaded gas). It has an E88 head and the the intake manifold has an E36 or something stamped on them. Also has a K&N.

 

Symptoms:

 

Hesitates when giving gas and likes to have the choke on a little bit. When the choke is off (low idle) it hesitates, but with the choke on (raising the idle) it responds a lot better to giving it gas.

 

It also gets horrible mileage.

 

Current Diagnosis:

 

There is a cylinder definitely missing (valve problem? all wires at distrib are getting spark), the vacuum advance isn't working. Runs really rich.

 

 

Solution:

 

New distributor (or a new vacuum advance, can I buy one somewhere?), rebuild the carbs? Get the head rebuilt for unleaded gas or try to get a head from a later car that can run on unleaded?

 

I'm not sure what the issue is or where to begin, any help is much appreciated!

 

-Buma

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try having the valves adjusted my 260z was the same and i had the valves and timing and carbs all adjusted for 100 dollars and after that it was so quick when i took off it somed the tires, so its prolly your valves, and check your timing and then sync your carbs thats all i can think. also does it pop or backfire if you give it too much gas or floor the gas pedal??

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ya thats what mine did too, i would have your valves adusted first then have the timing checked, and then clean out your carbs and sync them together, if it still does it than you have a different issue cause my car would run just like yours if i have the choke on it ran fine but wasted hella gas, and if i didnt it would be slow and have no power and also backfire. also check your oil and se if it smells like gas cause another common problem is the valve stem seals go bad and alow oil and gas to flow between them, and that also causes bad gas milage.

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Did this car ever run good? If so, did you play under the hood and it start running poorly? Have you done a basic tune-up? You'd be amazed what plugs. wires, cap, and rotor will do for an engine. Adjusting the valves is easy enough but won't cure problems like yours unless things are really out-of-wack. Look at posts 6 and 16 in the link provided. It tells you how to tune/sync SU's. It's quite simple. http://classiczcars.com/forums/showthread.php?t=23101&highlight=su

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Went and got a timing gun ( with a tach) and set it to factory 8 before top dead center and it ran like rap. It would hesistate and backfire when giving it gas.

 

So we manually advanced the distrib and where we could make it run better and get rid of most of the hesitation is at 18 degrees BDC. It's kinda confusing but it works.

 

Also I noticed that on the electrical diagrams, there should be two greens and a yellow running into the distrib, but mine only has the greens and there is no cut yellow in site.

 

Is there anyway to id a year's distrib?

 

(This car is such a hodpodge of parts and I think monkeys have previously worked on it)

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The yellow wire is usually run to the thermostat housing for your water temp sensor. Mine was hooked up to my distributor for some reason when I bought mine. As long as your distributor is working correctly and the timing is set (mine is at about 16 btdc) as well as having the plugs in the corrrect firing order, the next order of business I'd suggest is to fiddle with the carburettors. There are some very good writeups on how the SU's work if you search online. Buy or borrow a carb synch tool first off, you could be way off as far as having them synchronized together. Next I'd check the fuel metering screws on the bottom of the carbs to make sure they're set at the appropriate levels (can make them run rich or lean). Also check to ensure the carb pistons are traveling fully as well as making sure they have oil in the domes for damping. At least that's what I'd try.

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Thanks guys! Next thing on the list will be to look into setting the mixture. The carbs have been synced at a shop, so I don't have to worry about that.

 

I am bidding on a E88 (rebuilt + unleaded compliant) on ebay and am wondering all what will be involved to put in on.

 

Will I need new studs for the block / head? New Head gasket? (no leaks currently) Intake manifold and exhaust header bolts? A new valve cover gasket? A tool to remove/install the timing chain?

 

What work should be done on the head before going on? Dremel + brass brush to valves / chamber and bottom of head?

 

How long will this take? Two days?

 

Sorry I'm such a newb :(

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