1976 2.0 question, throttle body Options

[Bleyseng]

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[Dave_Darling]

QUOTE (jimkelly @ Jan 9 2006, 03:34 PM)

Captain wrote opposite Dave ...

Actually, I think that the Cap'n agreed with me. He was, however, talking about the fittings on the throttle body, not those on the distributor dashpot. (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

--DD

[Bleyseng]

Lookat the 73 2.0 Throttle body with the two ports!

[jimkelly]

Thanks to you guys my baby is feeling a lot better now!

[motorhead]

this is interesting! I've had the advance side of my 76 hooked up to the TB forever. Mine is a CA car with EGR, so it has the same ports as the 73 above. Vacuum at mid throttle for the EGR. Guess I just assumed it needed to be hooked up to the dizzy too. This explains why I have to run a tee in the line to hook up the EGR when I smog it. Think I'll go mess with it a bit and see if it improves light-throttle driveability.

Also my $.02 on your backfire on decel. Thanks to Headrage, I eliminated 95% of my pop on decel by leaning out the CO adjustment on the brainbox. I have always kept it about 3/4 rich just to be on the safe side. Don't wanna burn a piston. Allan was following me one day and clued me in to the rich condition causing the backfire. Couple of test drives and adjustments and viola! no more backfire. thanks again Allan. (IMG:http://www.914world.com/bbs2/html/emoticons/beerchug.gif)

[jimkelly]

My understanding is the adjustment screw on the ecu is for idle only and does not effect motor at above idle ?? Jim

My problem has been solved - thanks to rtowle - my mps was BAD : ( but I had an extra : )

[Bleyseng]

QUOTE (jimkelly @ Jan 10 2006, 04:15 AM)

My understanding is the adjustment screw on the ecu is for idle only and does not effect motor at above idle ?? Jim My problem has been solved - thanks to rtowle - my mps was BAD : ( but I had an extra : )

The ECU screw only adjusts the mix at idle but it can affect the mix when the throttle is closed on decel IIRC.

[jimkelly]

On my 1976 2.0L I changed my bad 043 mps to a good 049 mps. While things appeared at first to
me much better - and are in fact much better - because back firing is esssentially
gone - I have noticed this problem. Maybe I did not notice it immediately because
my drive to work is extremely short - 5 miles. I have taken two bit longer trips recently
and found that after letting my car warm up in the garage for 5-10 minutes - for the first 10-15 minutes of my drive everything seems fine - I can rpm up too 4000 smoothly but after another 10 minutes or so it starts to hesitate at 3000-3500 rpms. If I come to a complete stop _ red light or stop sign - a few minutes later - coming off the light I find that the hestiation starts even earlier that 3000 rpm. I have one problem that I know of - my FI plug to one of my fule injectors is lose-ish ut tis does not appear to have been my problem causing this hestitation problem. Any idea if this could be being caused by a bad head temp sensor or position switch? Note problem does not occur withing first few minutes of driving but does become apprent after 10 or so minutes of driving and them worsens.

http://members.rennlist.com/pbanders/DJetP...tm#troubleshoot

[Bleyseng]

Its because in the first 10 mins of driving the engine is running rich as its warming up due to the CHT. After 10 mins the leaner A/F mix of the 049 is causing you the missing/hesitation. You should get the proper MPS for your car-a #043.

I would also change out those rubber vacuum hoses to the proper ones and look for vacuum leaks. Its like a dog chasing its tail if you have vacuum leaks.


(IMG:http://www.914world.com/bbs2/html/emoticons/yikes.gif)

[jimkelly]

geoff,

I have a 043 mps that I got from skline and another from root locally but for some reason my car won't idle nicely with these : (

It idles fine with the 049 : ) but bucks like a bronco under throttle : (

There is no question the 043 previously in my car was bad - my car backfired like crazy and I can suck thru it with my mouth.

Do you think it could be a timing issue that is not letting the 043's allow my car a decent idle even though my car will idle fine with the 049??

Jim

[Bleyseng]

If the 043 is bad then its waay to rich so the motor can't handle the extra fuel to idle. If the MPS is bad the engine can't pull the diaphram back with vaccum to the inner stop so it runs too rich.



Geoff (IMG:http://www.914world.com/bbs2/html/emoticons/popcorn[1].gif)