ignition/ poor running problems

[Aaron Ryba]

1987 4kcsq 105k mi

Concerning the ignition system the Bently manual/
Bible lists diagnostics and system descriptions for
the 4cyl CIS-E and gt coupe
CIS-III engine however there is nothing more than a
page of statistics for the 5cyl JT (?) coded CIS-E
quattro engine.
Am I to assume that the JT engine ignition is the same
as the 4cyl system?

Does the JT have a knock sensor and warning light? A
hall sender and receiver?
I have been troubleshooting an intermittent poor
running condition where the engine suddenly looses
power and runs as if the timing
is off, sputtering and possibly backfiring through the
intake ( a loud popping noise of the air flow sensor
plate in the intake is heard
when throttle is applied at time of poor running).

This condition happens spontaneously and vanishes
within a few seconds only to return again a few
minutes or hours later of driving
when running at 3-4k operation revs.
Engine is prone to this condition more so at idle.

Knock sensor warning lamp #1 does not light up at
accessory ignition turn nor at start up.
Attempt to troubleshoot knock sensor syst. by
inserting fuse for at least 3 seconds into fuse slot
in fuel pump relay #10 (which
grounds the #1 warning lamp) was unable to be
performed because my fuel relay #10 has no fuse slot!!

So, either I have an incorrect #10 fuel pump relay or
the JT ignition syst. is not the same as the 4cyl
ignition syst.

Can someone verify this??

What might be the possible problems with the timing??
The spontaneous behavior, surfacing and disappearance
of the condition make
me think that the problem is electrical, I.E.
ignition.
Engine has new spark plugs and wires, and relatively
new rotor and cap.

What happens when the vacuum line to the TCI-H unit
(hall receiving unit) is bad??
Is this just a bad connection in the wiring within the
ignition syst (TCI-H unit, hall sender in distributor,
ignition coil, wires)?
What might happen if the ignition coil is not properly
grounded ( I have found an open ground wire from a
possible pre-existing alarm
syst off of the ign. coil)?

Also, what are the symptoms of a bad fuel pump. Does
it kick the bucket immediately or could the pump
intermittently fail to keep
enough pressure in the system? Mine has the typical
loud wine nose now.

I have pulled the fuse to the CIS-E power #23 while
this poor running condition is happening and it seems
that the fuse connection is
fine and working properly, so a bad elec. connection
there has been ruled out as the problem.

Thanks in advance

Aaron Ryba
87 4kcsq
91(?) Tamiya Celica GB. R rally 1:10 scale




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