4Age Ignition Issues.

[B.L.Z.BUB]

Hey guys. Sorry to ask this as normally I'd try diagnose it myself, but I'm at work and the shops are closed tomorrow so I'm trying to see if I can get an answer so I can get parts today when i do deliveries.

 

Just rerplaced my plugs and points. (4AGE bigport)

 

My issue: Seems fine accelerating, when cruising at low throttle its jerking and coughing a bit. Plus backfires and stalls.

 

I'm pretty confident I have the right leads.

I put NGK BCPR6 (or 5 I'm not sure)EY-11 plugs in pretty sure the 6/5 number shouldnt affect it but did I get the correct plug gap? There were two listings for 4AGE a 0.8 and a 1.1 gap. Or could it be that they are the Y and not the P plugs?

 

I'm hoping its something simple.

 

Any ideas appreciated!

 

Cheers

 

Reed

[B.L.Z.BUB]

Anyone?

 

Echo.... echo....echo.....

 

[ke70dave]

the big question is, how did you replace the points in a bigport distributer? They don't have points.

 

id be looking at your TPS. unplug that, see if it fixes the problem. there is a little switch in the tps that tells the ecu its at idle (or zero throttle), if the adjustment is out, it might think your at idle when you are trying to drive. not good.

 

if you unplug it the engine will still run "fine", just not as agressive on throttle input (what i found anyway)

 

oh and check the gap in the manual, and gap it yourself using feeler gauges. i don't trust the gaps from the factory, could have been bumped etc. best to set them yourself.

Edited April 24, 2012 by ke70dave

[B.L.Z.BUB]

Sorry typo I meant leads :o

 

Seems strange as all I did was replace plugs and leads. Wouldn't think it'd throw anything else out.

Edited April 24, 2012 by B.L.Z.BUB

[carbonboy]

Just rerplaced my plugs and leads. (4AGE bigport)

 

My issue: Seems fine accelerating, when cruising at low throttle its jerking and coughing a bit. Plus backfires and stalls.

 

I'm pretty confident I have the right leads.

I put NGK BCPR6 (or 5 I'm not sure)EY-11 plugs in pretty sure the 6/5 number shouldnt affect it but did I get the correct plug gap? There were two listings for 4AGE a 0.8 and a 1.1 gap. Or could it be that they are the Y and not the P plugs?

 

I've got an NGK catalogue here, for the AE82 4AGE (bigport) it lists BCPR5EP-11 (platinum plug, 1.1mm gap) from 1986 -1988. For the AE82/AE93 4AGE from 06/1989 - 07/91 it lists BKR6EP-8 (0.8mm gap), pretty sure this is for the smallport motor as I ran the 1.1mm gapped plugs in my AE82 bigport with no problems. My Haynes manual tells me BCP6EY-11 or equivalent (non-platinum, 1.1mm gap) so you have the right plug.

 

The only differences I've found betweeen the Y plugs (non platinum) & the P plugs (platinum) is service life & purchase price, platinums are around $30 each.

 

BPR5EY-11 (1.1mm gap) are for a 4AC engine.

BCPR5EY (0.8mm gap) are for a 4AFE engine.

 

id be looking at your TPS. unplug that, see if it fixes the problem. there is a little switch in the tps that tells the ecu its at idle (or zero throttle), if the adjustment is out, it might think your at idle when you are trying to drive. not good.

 

if you unplug it the engine will still run "fine", just not as agressive on throttle input (what i found anyway)

 

oh and check the gap in the manual, and gap it yourself using feeler gauges. i don't trust the gaps from the factory, could have been bumped etc. best to set them yourself.

 

+1 for double checking the gaps of the plugs you buy, some of mine have been out as much as 0.45mm straight out of the packet.

 

Everything in my manual re troubleshooting points to either the TPS/idle speed, vaccum leaks, incorrectly gapped plugs or damaged distributor components. Based off what you've fixed/replaced anyway.

 

Good luck! :y:

Edited April 24, 2012 by carbonboy

[B.L.Z.BUB]

Ok cool ill limp it home and check it all over. Just wanted to make sure they were right in case I needed to get different ones today.

 

I still have all the old ones so I can swap them out and over and see f there is a problem with the new ones too.

[B.L.Z.BUB]

Three out of four plugs needed to be re-gapped. Didn't have a 1.1 so I used a 5.3 and a 5.2 he he learn something every day. Don't trust $5 spark plugs. Cheers guys, appreciated as always.

[ke70dave]

did it fix it?

 

how far were the gaps out?

[B.L.Z.BUB]

I couldn't tell you how far out but enough to be a problem. Maybe 0.3 - 0.5 ish !!!!! Enough for someone like me to go, damn that's not right.

 

Checked the plug boxes, all the same plugs. Must of got Tibor running the plug machine that day