4AGE Problems - Have to floor the pedal to get car started

dr.occa · Post by **dr.occa** » Mon Jul 09, 2007 5:06 am

Finally have the MJ all hooked up. Haven't taken it out on the street yet. Just ran the car in the driveway.

Here are the symptoms:

1.) Have to mash the gas pedal to the floor to get the car to start
2.) Coolant temp starts rising to 180 faster than before (all 4 ex. runners are hot)
3.) Exhaust note sounds like that of a small chainsaw
4.) Have to keep applying gas the gas pedal to keep the car running

I've tried adjusting the timing while the car idled but nothing I tried would smooth it out. I've used the Default_Map but nothing seems to bring that old 4AGE sound back...

Do I need to run it up the street and see how the car is running exactly?

When I was using the distributor, I was at approximately 15 BTDC and 35 at 3K and above (MSD fixed timing advance "computer" and 6al). Car ran wonderfully (26mpg! on dual 44phh mikunis even!). The MSD setup gave out on me and now it's back to square one.

Bumming...
dr.occa

Post by **brentp** » Mon Jul 09, 2007 6:18 am

Quick question:

Did you verify static timing of 10 degrees with the MJLJ disconnected, and the EDIS in 'limp home' mode?

Brent

MartinM · Post by **MartinM** » Mon Jul 09, 2007 8:45 am

Have you got the trigger wheel 180 degrees out?

Try swapping coil 1 and 2 primaries over....

Post by **brentp** » Mon Jul 09, 2007 3:25 pm

Hmm- interesting.

When I fired up the Mr2 for the first time (way back) I invariably had the coil leads backwards, and it violently refused to even start! But perhaps wired backwards with some timing offset could allow it to run in this case.

Regardless, measure what's going on and report back.

dr.occa · Post by **dr.occa** » Mon Jul 09, 2007 4:50 pm

brentp i'll double check the coil leads. i'll also disconnect the mj and see if the car runs in limp home mode.

MartinM the trigger wheel 180 degrees out???...sorry, i'm a little confused by the question. are you referring to the crank pos. sensor location in relation to the missing tooth?

Post by **brentp** » Mon Jul 09, 2007 5:00 pm

Ok- also do please put the timing light on it and measure the static timing!

dr.occa · Post by **dr.occa** » Mon Jul 09, 2007 5:35 pm

brentp since it's the leads in question, i could just swap 1&4 spark plug wires w/ 3&2 to determine if the leads are crossed correct? i'll give that a shot and get a friend to put a timing light on the crank to see where it's at w/o the mj.

dr.occa · Post by **dr.occa** » Tue Jul 10, 2007 1:22 am

ok, tried just swapping 1&4 w/ 3&2 at the coil to check if the coil leads might have been crossed. car refused to start. put the plug wires back (1top & 4bottom > 3top & 2bottom with leads facing the ground). disconnected MJ, started up the car and fired up the timing light. here's what i got:

according to the timing marks on the gears in reference to the TDC marks on the cam gear back plate, the car looks to be at 10 degrees BTDC.

Post by **brentp** » Tue Jul 10, 2007 6:25 am

I watched your video. It's certainly somewhat before TDC but I'm not convinced it's exactly 10- it may be more, considering your camshaft runs at 1/2 crank speed. Do you have the timing marks left on your crankshaft and the block pointer? A direct measurement would be preferable.

Just curious, was it idling on it's own or were you holding the throttle open?

You might want to re-connect the MJLJ and try adjusting the group of cells in the idle region by -10 degrees, and then +10 degrees to see if your engine idles more like you expect it to.

Brent

dr.occa · Post by **dr.occa** » Tue Jul 10, 2007 2:06 pm

brentp, i am having to keep it idling with the gas pedal. it won't idle on its own. also, for vacuum i've tapped each of the runners on the intake manifold (after the carbs before the head) and connected them to a vacuum reservoir. i'll be picking up an external "analog" vacuum/boost gauge to compare against what mj is getting. unfortunately, there isn't a mark on the crank pulley to indicate timing. i do agree that the cam timing marks look like they're more than 10 degrees BTDC. i may just compensate via the adj. cam gears (just another option). i'll hook up the mercury vacuum tubes to each of the runners and see what's going on that way too.

MartinM · Post by **MartinM** » Tue Jul 10, 2007 3:34 pm

Looks like you're having problems with the basic EDIS install so measuring vacuum using an analog method as well isn't really going to help

A VR sensor, a trigger wheel, an EDIS module and a coilpack should give you absolutely rock solid 10BTDC (if correctly wired and TDC/trigger wheel/sensor position correctly synchronised) There's no ability for manifold pressure to affect the EDIS limp-home mode.

You could try plugging up the taps in the runners, just to make sure. If there's a problem there, then you've got the equivalent of a massive air leak after the carbs/FI (Heck, I don't even know what your engine's got for fuelling!!)

dr.occa · Post by **dr.occa** » Tue Jul 10, 2007 5:09 pm

i'll give that a shot MartinM: i'll plug up the taps at the manifold and see if that smoothes out the idle. if it does then we know it's a serious vacuum leak.

as for fueling, my holley red fuel pump went out so i'm just jusing a 4-7psi (more like constant 7psi!) mr. gasket electric fuel pump through a holley 1-4psi fpr>fuel distribution block to both mikunis (44phh). fuel pressure is good so now just having to figure out if there is a major vacuum leak or not.

dr.occa · Post by **dr.occa** » Thu Jul 12, 2007 3:47 pm

i've made sure the pickup sensor is right on the 9th tooth. it's maybe 1-1.5mm away. i've even swapped the EDIS unit (1 white label and 1 red label) with another EDIS4 unit. tried testing it w/o mj and it's still the same: it'll idle at @10 BTDC if i keep the gas pedal pressed down a bit but the car still won't idle and advance right. i've attempted lowering the timing to 5 and the car just dies. i've set it up to 10 but I have to keep my foot on the gas. it will accelerate as i press the gas pedal further but as timing advances the car sounds nasty (like one of those little mini motorcycles that were popular a year or 2 ago).

plugged up vacuum ports and no difference. disconnected the mj's vacuum hose and it still "idles" in the 100KPa area. Maybe I need to replace my mj

the header starts to smoke as the engine heats up. i'm getting good fuel pressure and consistent compression and just installed a new MSD coilpack so it maybe the carbs. they're about 30 years old so i've begun rebuilding them.

KLAS · Post by **KLAS** » Thu Jul 12, 2007 4:54 pm

maybe your VR sensor is to far away, all i know are running 0.8-1.0 mm
did you check if the VR polarity is correct?

if you can not make it idle even without MJLJ i don't think the problem is MJLJ related

dr.occa · Post by **dr.occa** » Thu Jul 12, 2007 5:48 pm

KLAS wrote:maybe your VR sensor is to far away, all i know are running 0.8-1.0 mm
did you check if the VR polarity is correct?

if you can not make it idle even without MJLJ i don't think the problem is MJLJ related

if the VR sensor were incorrectly wired would the edis (not the MJ) even start up the car period? i was under the impression that if it were incorrectly wired it wouldn't even fire up the ignition at all. could someone clear this up for me?

in my case the car does fire up but won't hold an idle. anyway, the carbs are being rebuilt so i'll find out the source of the problem through by process of elimination. still, i'm open to other ideas and suggestions.