LWBJR
New Member
OK guys... So this is my first post on CC. I have gotten so much help in the past from reading previous CC and HT threads that I knew where I'd go when my son's Civic started acting up. So here's the deal:
88 Civic LX, 1.5 ltr, DPFI, 4-door, automatic trans, 140K
A few days ago it sputtered and then died up on acceleration from a stop. When he attempted to start it, it turned over but would not start. He and a couple friends pushed it home (just down the street, luckily). Upon inspection we determined no spark. After testing we proceeded to replace the coil and then the igniter, only to discover no change. Plugs, plug wires and grounds appeared good. We finally ordered and installed a new dizzy and it started right up! We set ignition timing using a timing light. It idled fine, but when we depressed the throttle, the tach would only go up to about 2400 before dropping down to 2000 and oscillating back and forth under load. Once we let go of the throttle, it drops back down to a normal idle. The ECU flashed 7 (TPS). So, we went to the wrecking yard, pulled a TPS, installed and adjusted it on the car. Literally, for the first 3 to 5 seconds that it ran the tach responded properly to the depressed throttled. Then it went back into oscillating between 2000 and 2400 when the throttle was held steady. Still getting a CEL 7 from the ECU. Upon original test of the TPS it appeared to increase voltage appropriately with increased throttle. When we tested it again after noticing the oscillation continued, however, it appeared to have a "dead spot" very early on the process. So, it starts at 0.5v and if the throttle is depressed slowly, the voltage will very briefly drop to ~0.1 or so before resuming the normal increase.
A couple questions:
1. What the hell?
2. What's the link between the TPS and the dizzy? Why would we get no spark, replace the dizzy and have a TPS problem?
3. Would a brief "dead spot" in the TPS cause it to go into oscillating RPMs?
4. Any ideas on what to look at next?
A couple notes:
1. Although we get spark since installing the new dizzy, it is not a strong spark (orange in color rather than white)
2. We checked the timing marks on the cam sprockets and crank pulley to verify the belt had not jumped cogs.
3. Normal pressure in all cylinders.
Any advice would help... Thank you in advance!!
88 Civic LX, 1.5 ltr, DPFI, 4-door, automatic trans, 140K
A few days ago it sputtered and then died up on acceleration from a stop. When he attempted to start it, it turned over but would not start. He and a couple friends pushed it home (just down the street, luckily). Upon inspection we determined no spark. After testing we proceeded to replace the coil and then the igniter, only to discover no change. Plugs, plug wires and grounds appeared good. We finally ordered and installed a new dizzy and it started right up! We set ignition timing using a timing light. It idled fine, but when we depressed the throttle, the tach would only go up to about 2400 before dropping down to 2000 and oscillating back and forth under load. Once we let go of the throttle, it drops back down to a normal idle. The ECU flashed 7 (TPS). So, we went to the wrecking yard, pulled a TPS, installed and adjusted it on the car. Literally, for the first 3 to 5 seconds that it ran the tach responded properly to the depressed throttled. Then it went back into oscillating between 2000 and 2400 when the throttle was held steady. Still getting a CEL 7 from the ECU. Upon original test of the TPS it appeared to increase voltage appropriately with increased throttle. When we tested it again after noticing the oscillation continued, however, it appeared to have a "dead spot" very early on the process. So, it starts at 0.5v and if the throttle is depressed slowly, the voltage will very briefly drop to ~0.1 or so before resuming the normal increase.
A couple questions:
1. What the hell?
2. What's the link between the TPS and the dizzy? Why would we get no spark, replace the dizzy and have a TPS problem?
3. Would a brief "dead spot" in the TPS cause it to go into oscillating RPMs?
4. Any ideas on what to look at next?
A couple notes:
1. Although we get spark since installing the new dizzy, it is not a strong spark (orange in color rather than white)
2. We checked the timing marks on the cam sprockets and crank pulley to verify the belt had not jumped cogs.
3. Normal pressure in all cylinders.
Any advice would help... Thank you in advance!!