John Pirtle

This has been a great thread ! I was betting on some sort of air intake or exhaust restriction/issue. You don't hear much of Hall sensor problems....

Yeah I'll bet you're happy.

I used to have an occasional clunk that turned out to be a bad shock. Best of luck.

worf928

Excellent. I'm glad you enjoyed it.

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I was betting on some sort of air intake or

I've R&R'd a 32v intake four times now.

And, I can do that job right in my sleep. I was really not worried about an intake problem.

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exhaust restriction/issue. You don't hear much of Hall sensor problems....

Yeah. They do not seem to fail too often. I was really hoping that someone had BTDT and had a way that involved something less that cracking the fuel lines, disconnecting the air pump valve, removing the cam cover, replacing the sensor, putting the cover back, then having to pull the fuel rail because of that stupid friggen 10mm bolt that's under the rail that bolts the hard line guide. I spent AN HOUR trying to get the right angle on THAT F@!(#*& bolt before pulling the rail. 8 hours total wrench time for that sensor - 3 hours to get it out and 5 to put everything back together. Blech.

But all's well that end's well.

Oh and tools. Does anyone make a 'gear wrench'-like tool that will undo Allen bolts? You'll KILL for something like that if you ever do the Hall sensor.

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Yeah I'll bet you're happy.

Momentarily. Now it is time to do the suspension so that I can drive it. And, oh yeah. It has no heat because I blocked off the leaking heater core. And - OF COURSE - it has no A/C. Oil pan leaks like a sieve. And, what motor mounts? Eventually, this 89 will be ship-shape. And I will have turned every bolt on the thing. But, that was the point of the whole 89 exercise

BTW, John, I've pointed folks at your excellent t-belt procedure. If I haven't thanked you in the past for that yet - let me say now: Thanks!

SharkSkin

Would something like this, this, or this help at all? I found a very low profile ratcheting screwdriver that takes hex bits at a local hardware store.... it's smaller than all of those. I can send a pic if you'd like.

worf928

Ja. Them (the first two) would be the cat's meow.

Gonna have to get me some a'dem.

A ratcheting Alan wrench will shave an hour or maybe more from the Hall sensor R&R. Won't let you get to it without removing the cam cover. But, your fingers and hands will thank you.

Old & New

It may be a moot point now, but I am just tying up loose ends.

worf928

Those sure look like the same numbers I found.

In any case my idling pressure is closure to 48 PSI and 55+ with no vacuum.

I didn't do a 'relay bypassed engine-off' test. But, I suspect that the idle test with no vacuum/strong throttle blip at 55+ psi is a good indication that my pressure is OK.

Last two thoughts:

- we'll see on the dyno on Saturday how close to spec the power level is

- I'll bet that there are still a few things wrong with the '89 and if the dyno says the same then I'll chase some of the good ideas tossed into this thread.

worf928

Long dead thread. But, I promised to post dyno results:

270 rwhp

Paaaaa-thetic. (But still about 100hp up from when this thread started.)

The curve shows the characteristic zig-zag of timing being retarded then advanced then retarded then advanced - i.e. knock sensors kicking-in.

The most-likely culprit is [Edit: removed incorrect earlier statement which was based upon what the Dyno operator told me, and that was wrong, wrong, wrong. (Maybe not for a small block chevy but wrong for an LH 928.)]

In the meantime baby's got a fresh new oil pan gasket, new rod bearings, ford motor mounts, and Eibachs with Koni externals with my 17" Fikse forged wheels (avatar) and new SO-3s, so I'm going to DRIVE!!!!!!!!!!

BWWWAAAAAAAAAAAAAAA!

Ok, maybe with that looser dyno score (for an '89GT) there'll be no burnouts, but the twisties are gonna quake in fear.

Mattman928

You may want to check this thread for other suggestions. You could also check the WOT sensor. Another easy trick, would be to swap the brains from your two GT's and see if the LH may be the culprit??


https://rennlist.com/forums/showthre...hreadid=142351

worf928

F/A ratio at WOT is spot-on as evidenced by the EGA map from the dyno.

Already ruled out. If not in this thread then in another.

BTDT. LH failed on the '89 a year ago. Had a spare '91 in for a while. Dyno run was on a freshly-rebuilt '89GT brain.