fourwhls

iTrader: (2)

Alright....Here's the scenario.

1992 Chassis, 2000 Engine, MP62 SC, 460cc injectors

1992 Wiring, 2000 TPS, 2000 IAC

90-93 MSPNP

Previously:
I was running a Link naturally aspirated and the car ran great. Removed the Link, converted the wiring back to stock and installed the MSPNP.

Problem right now...
Very weak spark on #1 and #3 cylinders.

Bringing you up to date:
I installed the SC and MSPNP install Sunday. I used the 90-93 msq from DIY and changed the reg_fuel and PW to reflect the 460 injectors.

Tried to fire it up with no luck. I read as much as possible and started making changed based on what I read. Nothing seemed to make any difference.

At this point I assumed something mechanical. I pulled the plugs and found that the #1 injector was not firing at all. Come to find out, the freshly cleaned injector was stuck. I pulled it, blew some air through it and hit it with 12v which cleared it up.

I thought that was the issue. Went back tot he base msq and started tweaking again. Still no luck.

After checking spark, I found that I was getting extremely weak spark on the #1 and #3 cylinders. The other 2 look great. Now if it was 1 and 4 or 2 and 3, I would assume a coil and change it out, but it's 1 and 3.

We used megatunix and recorded the trigger pulses. With the plugs out of the head, the trigger plots were great. Right on the money. Now we recorded it again with the plugs in the head. It was a mess. We turned it over for about 10-15secs and it only recorded about 12 triggers. WTF

I am stuck...Any thoughts?

I am going to borrow a stock ecu tomorrow and verify the hardware is working correctly. We are also going to plug the PNP in a stim and verify everything is working properly.

Can you think of anywhere else to look?

Bryce

iTrader: (24)

Possible grounding issues?

FoundSoul

iTrader: (5)

We'll be glad to take a look at the box if we need to, but I'd be quicker to suspect the coil pack or possibly even the ignitor with weak spark just on 1 & 3. With all of the custom work (engine, etc) are all of your grounds good?

samnavy

iTrader: (7)

I have a spare coil pack out of the motor I bought... you're welcome to it to try troubleshooting.

Dare I ask if all of the sensors are visible reading properly working in Megatune... not something simple like a coolant or IAT sensor fouled?

Perhaps cleaning the connections on the coils? Trying different spark plug wires?

IcantDo55

iTrader: (11)

I still think even with only 2 cyc firing and 2 cyc firing weak it would start. Something else is wrong.

richyvrlimited

iTrader: (1)

coils are shared 1&3 and 2&4. Firing order is 1432 so if they were shared 1&4 3&3 you'd get no spark on 2 cylinders as the coils are fired alternately.

So IMO either your first assumtion is correct, dead/dying coilpack, OR you have your HT leads to your coils hokked up wrongly....

Braineack

iTrader: (62)

this would be the case if were were talking about injectors.


coils are 1&4 and 2&3
injectors are 1&3 and 2&4

richyvrlimited

iTrader: (1)

doh, sorry!

fourwhls

iTrader: (2)

I checked the grounds again last night and even relocated them to a different location on the block. I don't know? I only took apart the passenger's side of the engine compartment. I have 2 ground lugs that were originally bolted to the 1.6 intake manifold, I now have them mounted the valve cover. I 1st mounted them to the new intake manifold, but wasn't sure about the grounding properties being that the manifold is anodized.

As far as the spark goes....If it were 1 & 4 or 2 & 3 weak, I wouldn't question where the problem was. But with 1 & 3 weak mean I am getting 1 weak spark and 1 strong spark from each coil. That doesn't sound right.

The coil/ignition wiring was never touched during the SC install and the car was running great when I pulled it in the garage.

A friend is going to bring by his car (93) either today or tomorrow. I am going to start swapping hardware to verify everything is working before I assume anything.

I love chasing gremlins.

Braineack

iTrader: (62)

maybe it's just the spark wires???

IcantDo55

iTrader: (11)

Or spark plugs.
I had a set of Champions that had one mysteriously stop sparking and drove me crazy on a boat motor years ago. I learned my ABC's from that one.

Anything
But
Champion

Plugs.

magnamx-5

iTrader: (7)

Check your grounds and your wires maybe try swaping the wires around to see if the problem moves. Initialy i though the porblem might be coils. Also what are your Dwell settings? To little dwell and you might not make enough voltage to fire both plugs

FoundSoul

iTrader: (5)

I'm not sure it has anything to do with the spark-- good news though, I just got a call from Peter Florance who has been a part of the MS project as long as anyone and he's helping Shawn out with his rather custom setup here. Peter is an electronics tech with all the equipment that goes along with that, and tons of MS experience. I may have you guys send the unit back to me to drop on my car and I can confirm once and for all the issue isn't the box, but he says the fuel pump is priming and fuel pressure is good, all four cylinders are sparking (and you can get these cars to run badly on 2 cyl usually) but he's suspecting the injectors may/may not be working properly as they were cleaned and then sat for a while it seems, and that can be bad news allowing them to seize up, I had this happen once though it was only one injector and it freed up on it's own.

Apparently they are using the 1.6 CAS so that's good. Peter can scope the outputs from the ECU to the ignitor and make sure they're good, and from the ignitor to the coils...

He says it's kicking back like the timing is way off.... could the CAS be WAY out of adjustment? Could the timing belt be off a tooth or four?

-J

fourwhls

iTrader: (2)

Anything is possible...it's just going to take some time to check everything. I will say that I am very lucky to have Peter helping out. I'm pretty sure he ranks right at the top when it comes to MS users.

The injectors may be an issue, but I don't know. They were cleaned about a month ago and sat on my bench for a month. I don't think that is a long time, but that's me.

I don't believe the timing is off. I installed the Link about a year ago. The car was running good with the stock ecu and then again with the Link. I set the timing at 10 deg when the link was initially installed and I haven't had the motor apart and I haven't changed anything since.

I have the '00 1.8 injectors that came out of the car. Just for a sanity check, I can put them back in and see if it makes any difference.

I also want to go back and recheck all the wiring modification I made when returning the wiring to stock after removing the link. I'm pretty sure I reversed all the changes, but again you never know.

I'm sure we will get this resolved. It will take some time and trial and error, but it will get done.

FoundSoul

iTrader: (5)

If it's only been a month since you had the injectors cleaned they shouldn't all be seized unless they used glue . I know you had the one that was, but...

If you want please do send the unit in and I'll throw it back on my car again and give it a quick test. We can rule that in or out real fast...

fourwhls

iTrader: (2)

I really appreciate the offer Jerry and may take you up on it, but I want to make sure the problem is not my car 1st.

If my car was a stock '92, I would have sent the unit to you already, but my car is far, far from a stock '92. I want to double, tripple check all my work first.

Plan of attack for the next two evenings:
Recheck all the wiring changes from the Link
Recheck all the grounds
If both of those are good to go, I will install the stock injectors, stock ecu, and stock AFM and see what happens. I will have to disconnect the TPS and IAC, being that I am using '00 TPS & IAC. I don't know what kind of ill effects that will cause, but we will find out.

If all fails with those attempts, Peter will be back over Saturday with scope in hand to help me sort through this mess.

samnavy

iTrader: (7)

DUDE!!!!
I'm in for helping out whether you want it or not... I'll be over Sat if you're still troubleshooting. I want to see your little shop/barn and check out a set of these end-links. I'll call ya!

fourwhls

iTrader: (2)

Sounds good...The more the merrier. Give me a call.

FoundSoul

iTrader: (5)

Just a thought... when you turn it over, what are your PW when it's cranking? Not the settings, the actually PW readouts on the gauges. I want to make sure it's not reading your TPS funny and going into flood clear mode, which will cut off the injectors.

Rafa

iTrader: (22)

I don't know anything about this but; if Peter suspects the injectors; what would happen if you interchanged them to a different order?

That way at least you'd be sure it's not the injectors.

Sorry.