kevin camps

Checked for vacuum leaks today, sprayed some ether by all the gaskets. Looks to be a tiny leak by the egr valve and next to the throttle body, I spent a hour getting all sorts of fuel trim readings so here’s the list maf unplugged at idle fuel trims good mag plugged back in, truck still running, fuel trims good maf reads 4.24g/second at idle as long as the truck stays running since the maf was plugged back in the fuel trims stay good when driving truck shut off and restarted with maf plugged in, fuel trims good, maf reading 9.05 at idle drove around the block, maf plugged in, fuel trims very high, maf reading 4.62 at idle I will get some gaskets on order and do new plenum, egr, and throttle body gaskets, plenum gaskets have been removed and reinstalled a fair few times so it could be leaking in the middle by the injectors aswell

I will check for leaks Tomorrow, truck has headers and a full exhaust with no cats so it’s not a flow problem

I managed to run home quick to run some tests, testing vacuum from the manifold it’s a steady 17inHg, increasing when i apply throttle, fuel trims slowly creep up after snapping the throttle, cleaned the mag sensors then all fuel trims are in spec, truck doesn’t stutter or bog when the maf is unplugged..

Thats what Im beginning to think aswell. Sucks that all my tools are at home, I’ll try to get home tomorrow and do some digging. I’ll let you know what the results are

I had the scanner hooked up yesterday, tps readout seems good, bank 1&2 long term fuel trims we’re high while cruising. I didn’t check what it did when it was having the issue

SOLVED: ended up pulling out the parts cannon and threw a new coil in it even though the old coil tested good, sure enough that’s what it was, the spark must have been just weak enough to not be able to gap the rotor to the points, truck runs and drives now but still falls flat on its face if I’m idling at a stop light for more than 10 seconds, idles fine and there no cam timing codes, fuel pressure tested at 50 psi at idle, I’ll probably do new plugs because it’s been 50k since my last change and go from there, I’m living in the city during the week for school so I’ll live with it until the weekend i should add that if I’m stopped and hold the break/gas so it stays around 1000rpm it won’t stumble, when the truck stumbles it’s so bad it seems it might stall right in the middle of the road

Yeah distributor turns while cranking, I put a new one in because the old one has a good amount of play. I’ll mess around with it for the rest of the afternoon and see what comes up

Brand new rotor and cap came with the dizzy

UPDATE: picked up a brand new distributor, plugged her in still no cherry, I pulled the cap off and between the center hot electrode and ground I get a good strong spark, but then from the #1 cap plug to ground nothing, even if I shove a regular wire in it. It seems like the cap might somehow be shorting to ground somewhere. The plot thickens haha

also tested all the points for continuity to the plug

Here’s the rotor, I gave everything a quick sand before it got put back together, I find it very strange because everything worked fine before I took it apart

Does the coil timing have to be spot on with when the rotor passes the point? Just cranked the engine to see the coil arcing to ground consistently

I will be picking up a spark tester tomorrow, I just checked the primary and secondary resistance on the coil and everything is on spec according to my Haynes manual

I checked from the plug to ground and it read 12v with key in ignition, and would load-safety my multimeter when I cranked it over, it’s a 1000v multimeter

454 vortec - replaced a lifter after I got sick and tired of the ticking noise it was making, that Ofcourse means I had to pull the intake and distributor, after the swap I put the intake back on and installed the distributor, I didn’t think to mark it when I pulled it out so I brought #1 cylinder to tdc compression then installed the dizzy so that the rotor would point to the number one point, put everything back together and now cranks but no spark. I’ve spent the past couple days messing with it and at this point am at a loss, I pulled the top plenum and plugged all sensors in and such, coil and the cam sensor. The injectors will pulse and when I put a multimeter between the plug wire and ground I will get a fluctuating voltage. But no spark, and help is appreciated and thanks in advance first post here so let me know if I left anything out, kevin