vieroski

After much forum searching and plenty of testing, I've found myself stumped on an issue I am having with my '88 pickup 3vze. So here goes.

My truck has been lagging off the line for the past few weeks and, seeing how I never did a compression test prior to purchasing the truck, I decided now was the time. I've put about 30k on the truck since I bought it, and it has 208k now. It has got very hot on me several times while driving up to the mountains, so I thought I may have blown a head gasket. So I picked up a new set of plugs figuring why put the same ones back in at this point. The PO kept pretty good records on all of his maintenance via receipt since he typically sent the truck to the shop when it needed work, and I didn't see any mention of this being done for a while.

Compression looked good all around and I did an oil change too for added assurance. No issues. Gapped the pluggs and put everything back together but when I go to start it I got a backfire. No biggie, probably mixed up a plug wire or something. I triple checked everything and all is good. Plugs are seated, wires secure, all routed properly. I tried to fire it up again and managed to get it to run, but very rough. I can hear detonation, so I figure I got the wrong plugs. I bought the NGK's, but they are the right ones. I had the Denso's in there prior, so I decide to put the old ones back in but the problem persists. At that point I decide to check the timing and find #1 firing off way early. The timing mark is straight vertical.. must be something like 50 BTDC.

I started searching here at that point and reading the fsm. At this point I've tested TPS, Airflow, signal generator and the air gap. All of them are in spec. My only guess now is that somehow the timing belt is no longer aligned properly. When the engine was running normally I could hear noises from the front of the engine that sounded like the pulleys going out, so I guess anything could happen.

I am curious what the bright minds of Yotatech come up with when hearing this. I'm also curious if I can pull the top timing belt cover with relative ease to confirm or deny any out-of-alignment. Thanks for the interest.

HighLux

you got the plug wires on wrong. triple check them.

vieroski

Oh should also mention the ecu isn't returning any codes.

vieroski

With the light firing so early, I'd figure that would mean that the #1 plug was mixed up, but it's not. With the wires cut to length pretty specifically, I'd imagine the only place I could do this would be the #2 and #4 cylinder, but that isn't the case. I've been through the order a hundred times.

Interesting though, the fsm says the dizzy spins clockwise, yet the cap shows an arrow going counter. The numbers on the cap also make it obvious that it goes couter-clockwise. Is that a misprint?

vital22re

iTrader: (2)

If the problem happened after you swapped the plugs out. Your firing order is wrong. Start at cylinder 1 and verify you have #1 on the cap. If the order is right, you probably damaged your plug wires.