90 Timing Problem
Thread Starter
2nd Gear
Joined: Jun 2003
Posts: 2
Likes: 0
From: Lake Orion MI
90 Timing Problem
Problem: Engine will not run with the bypass wire re-connected after the initial timing is set with the bypass wire disconnected. To run with the bypass wire re-connected, the timing must be advanced an additional 45 degrees (approx). This can be accomplished by rotating the distributor (CCW) or moving the plug wires up (CCW) one position. Problem started when the distributor spark module and magnetic pick-up were changed to try and correct a no spark condition. The ECM was then changed, but it had no impact. Later the original spark module and ECM were re-installed, but the timing problem remains. It’s thought the original no spark condition was caused by two low resistance (5 ohms) injectors, which shut the ECM off (somehow) when hot. All the injectors have been replaced, so the engine now starts (hot) albeit with the timing issue. Anyone have any thoughts on this. Thanks in advance.
Drifting
Joined: Mar 2001
Posts: 1,636
Likes: 3
From: Lafayette IN
Re: 90 Timing Problem (90-vetter)
Problem: Engine will not run with the bypass wire re-connected after the initial timing is set with the bypass wire disconnected. To run with the bypass wire re-connected, the timing must be advanced an additional 45 degrees (approx). Problem started when <snip> and magnetic pick-up were changed to try and correct a no spark condition. <snip>
Remove the cap and rotor. Look where the pickup coil plugs into the IGN module. Pull that 2-wire harness off, and flip it. Plug it back in. It will be snug since the connector is keyed, but you should still be able to do it (might need to break the locating pin off).
You might have to then tweak the base timing so that it will idle again with the wire disconnected. Once you get it working, reconnect the set timing wire.
Post up if it works and welcome to the forum. This was the first question I had asked about when I joined and unfortunately, it took me WAY too long to find the answer to.
[Modified by HighHopes85, 11:25 AM 6/17/2003]
Drifting
Joined: Mar 2001
Posts: 1,636
Likes: 3
From: Lafayette IN
Re: 90 Timing Problem (90-vetter)
You are welcome. If possible, contact me off list by clicking my name on the left hand side so it brings up my profile. If it is the same brand of part, then I have some serious issues to discuss with the manufacturer...this is the 4th occurrence of something like this.
FWIW, the plug is really only supposed to go one way. I matched up the way it plugged in and it was correct acc'd to the Helms factory service manual but in reality, the pickup coil is bad. I have been running with it flopped the "incorrect" way for a couple years now so it's your choice whether to return the faulty one or not. It was a real PITA to figure out even with a scope...because it really is working backwards...it just fires on the trailing edge vs leading edge(or vice versa...can't remember now).
FWIW, the plug is really only supposed to go one way. I matched up the way it plugged in and it was correct acc'd to the Helms factory service manual but in reality, the pickup coil is bad. I have been running with it flopped the "incorrect" way for a couple years now so it's your choice whether to return the faulty one or not. It was a real PITA to figure out even with a scope...because it really is working backwards...it just fires on the trailing edge vs leading edge(or vice versa...can't remember now).
