Major Break Up Issue

Foxybody95

Member
Sep 14, 2015
90
3
8
Hey guys I'm in need of some serious help. I have an 88 Gt hatch with a fully built 306 and I'm having some major ignition issues. For some reason my car breaks up terribly after 2k. It use to do this at 5500 but now its gotten much worse. When it breaks up its pretty violent it shakes the car and the tach goes nuts. This all started after My oil pump seized up and broke my distributor. The thing ran great before this happened. I replaced both the pump and distributor and this started happening I thought the distributor was at fault so I replaced it and the tfi and I have the same issue. Ive also tried multiple tfi's and still nothing helps. Now my cars always had ignition issues from the start due to someone hacking up the wiring on my engine harness. I spliced in a distributor harness a couple months ago and its been working fine till now. My coil is testing good spark plugs are all new and gaped correctly. It also seems to only happen when the car is warmed up. If you rev it up cold it will pull all the way to 6k no problem but as soon as it gets warm it starts to idle high and eventually the rpm will surge until it kills itself and if you rev it it will break up violently as i had stated before. Are these symptoms pointing to anything obvious or do I have a bigger problem on my hands?
 
  • Sponsors (?)


The PIP is a Hall Effect magnetic sensor that triggers the TFI and injectors. There is a shutter wheel alternately covers and uncovers a fixed magnet as it rotates. The change in the magnetic field triggers the sensor. They are often heat sensitive, increasing the failure rate as the temperature increases. Just because you installed a rebuilt or remanufactured distributor does not exclude the PIP as being the problem. Rebuilt or remanufactured distributors may have a defective PIP right out of the box.

PIP Sensor functionality, testing and replacement:
The PIP is a Hall Effect magnetic sensor that triggers the TFI and injectors. There is a shutter wheel alternately covers and uncovers a fixed magnet as it rotates. The change in the magnetic field triggers the sensor. A failing PIP sensor will often set code 14 in the computer. They are often heat sensitive, increasing the failure rate as the temperature increases.

Some simple checks to do before replacing the PIP sensor or distributor:
You will need a Multimeter or DVM with good batteries: test or replace them before you get started.. You may also need some extra 16-18 gauge wire to extend the length of the meter’s test leads.
Visual check first: look for chaffed or damaged wiring and loose connector pins in the TFI harness connector.
Check the IDM wiring – dark green/yellow wire from the TFI module to pin 4 on the computer. There is a 22K Ohm resistor in the wiring between the TFI and the computer. Use an ohmmeter to measure the wire resistance from the TFI to the computer. You should see 22,000 ohms +/- 10%.
Check the PIP wiring - dark blue from the TFI module to pin 56 on the computer. Use an ohmmeter to measure the wire resistance from the TFI to the computer. You should see 0.2-1.5 ohms.
Check the SPOUT wiring – yellow/lt green from the TFI module to pin 36 on the computer. Use an ohmmeter to measure the wire resistance from the TFI to the computer. You should see 0.2-1.5 ohms.
Check the black/orange wire from the TFI module to pin 16 on the computer. Use an ohmmeter to measure the wire resistance from the TFI to the computer. You should see 0.2-1.5 ohms.
Check the red/green wire; it should have a steady 12-13 volts with the ignition switch on and the engine not running.
Check the red/blue wire; it should have a steady 12-13 volts with the ignition switch in Start and the engine not running. Watch out for the fan blades when you do this test, since the engine will be cranking.
If you do not find any chaffed or broken wires, high resistance connections or loose pins in the wiring harness, replace the PIP sensor or the distributor.

The PIP sensor is mounted in the bottom of the distributor under the shutter wheel. In stock Ford distributors, you have to press the gear off the distributor shaft to get access to it to replace it. Most guys just end up replacing the distributor with a reman unit for about $75 exchange

PIP problems & diagnostic info
Spark with the SPOUT out, but not with the SPOUT in suggests a PIP problem. The PIP signal level needs to be above 6.5 volts to trigger the computer, but only needs to be 5.75 volts to trigger the TFI module. Hence with a weak PIP signal, and the SPOUT out, you could get spark but no injector pulse. You will need an oscilloscope or graphing DVM to measure the output voltage since it is not a straight DC voltage.
 
  • Like
Reactions: 1 users
Sounds good thank you i will try this today! I also want to add that i threw my old msd 6a box on it just outa curiosity and that stopped the break up. It still idles high and eventually surges but i can pull it all the way to 6k with the engine warm and it will not break up with the msd box does that indicate anything?