Swapped to newer 4A-GE Timing problems

[LokiRx7]

My 3 rib blue top bit the dust while cruising home on the interstate, wasnt doing anything out of line, I was doing about 60-65 and lost all power... Had to get a tow home, and checking the plugs and a compression test showed that the engine decided to take a really big dump....

I had a 1989 GT-S a few years ago, and after it was in an accident I parted it out. I saved the engine as it ran great, I have swapped it in and switched the intake manifold and all the water outlets to the MR2 specific ones. Now I also swapped the distributor since it didnt have the proper connectors to use it with my ignitor/coil pack.

I have had the distributor out a dozen times now and tried setting it several different ways. Now it seems that the firing order under the GT-S distributor cap doesnt match my MR2's cap. And it also seems that the caps arent interchangable it looks as if the GT-S's mounting tabs are in different positions... I am a little agitated to say the least, so odds are I am missing something very simple, I am sure of it.

With as many times as I have had the distributor out, I am sure that it isnt off by a few teeth, I always set the engine at TDC when removing it to make re-installation easier.

If anyone can shed some light on this it will be greatly appreciated. I am going to keep on trying different solutions until I find something that works. If at all possible I would like to avoid cannibalizing this distibutor because I now have a 1988 GT-S and it would be nice to have a spare.

[LokiRx7]

Well replaced the cap and wires and the car started, idles fine, no power whatsoever. Car will not move under its own power, perfect compression. Plugs dont indicate running lean.

Fires up great, but no power like I said. Am I off a tooth? Or several? Its a pain in the ass to line the rotor up with #1 because I am laying over the quarter stretched out trying to eyeball it, and if I set it off of the car it never fails I bump it on something and mess up the timing before I install it.

Does anyone have a hint or a way they do this to make sure its dead on?

This is DEFINATELY something to do with the distributor, I am 200% sure the timing belt is on right, I can easily double, triple and quaduple check it. I put a new one on while the engine was out of the car and made sure it was perfect.

I know I sounded like I was sure it wasnt the distributor, but I am used to working on AE92's and I can always set the timing perfectly on those. But the distributor is right up front on those...

[LokiRx7]

Not timing, I chopped up an old distributor cap and made it "see through" so that I could see where the rotor was at TDC on #1. Also made it conveniant to turn the rotor under the cap while stabbing the distributor.

Maybe the TVIS is stuck open? When I stab the throttle the car sputters and dies, hence low or no air velocity. But when I roll on the throttle it sputters a bit but will rev out strongly to the redline. Either that or the intake manifold gaskets need replaced.

[F0Bman]

You might be using the wrong timing cover on your engine, which will skew the degree of what it really is.

[LokiRx7]

Originally Posted by F0Bman

You might be using the wrong timing cover on your engine, which will skew the degree of what it really is.

I swapped, the entire engine, and all of its related covers and components. The only thing from my original engine are the water outlets, Intake Manifold, and Exhaust Manifold. The only reason I switched those is to retain my MR2 wiring harness.

The timing is dead on now, and I still have this problem.

[mr2silvertop]

its sounds like an intake or vacuum leak

[LokiRx7]

Thats what I am thinking now, I have checked the whole vacuum system against the diagrams in the manual. Everything is where it should be, and I recently replaced all the vacuum hoses to make installation/removal easier, and lower the chance of ripping hoses apart.

I have intake manifold gaskets on order, and I will try those next.

[mr2silvertop]

if not maybe a sensor port in the intake I had a truck that had a build up of carbon in the intake did the same thing.

[LokiRx7]

Well I switched over to the AE92 intake manifold that was originally for this engine, swapped all the sensors, throttle cable brackets, etc. Had to remove the EGR because it is slightly different between the MR2 and AE92.

New intake manifold gasket, plugged up all EGR vacuum ports, replaced TVIS with AE92 unit (Made sure it functioned properly before installation.) Checked TPS and rechecked it, well within spec.

Refuses to rev under 3K will sputter and pop and crack and die. If I repeatedly blip the throttle it will rev, once past 4K revs out like a champ....

Catalytic convertor? AFM? Injectors? I went back to the distributor and still dont see a problem there... But my timing light decided now was a good time to stop working, so I cant really check to be sure.

[LokiRx7]

Tachometer started going insane... Bouncing almost all the way around the gauge...

[mr2silvertop]

Originally Posted by LokiRx7

Tachometer started going insane... Bouncing almost all the way around the gauge...

maybe with this one its arching off the plug wire with the tach wire, or the dizzy cap is loose. meaning it'll move back and forth wouldn't doubt it considering all the time u've spent playing with it. also if it is the cat. then it will usually glow red/orange if its stopped up or you'll feel really low pressure out the pipe. what was the condition of the new engine when you put it in the 2. could be a carbon build up problem.

[LokiRx7]

Originally Posted by mr2silvertop

maybe with this one its arching off the plug wire with the tach wire, or the dizzy cap is loose. meaning it'll move back and forth wouldn't doubt it considering all the time u've spent playing with it. also if it is the cat. then it will usually glow red/orange if its stopped up or you'll feel really low pressure out the pipe. what was the condition of the new engine when you put it in the 2. could be a carbon build up problem.

Cap is always tightened properly, I cant afford to let anything simple affect my diagnosis, at least where I can help it.

Disconnected the exhaust no change, all injectors are firing...

I highly doubt the engine went from running perfectly, to having a carbon buildup problem after sitting in storage for nearly a year.

I appreciate the suggestions, but I am really scratching my head on this one...

[mr2silvertop]

I'm just throwin out any possibilities online diagnosis isn't easy. Sittiing for a year you say? That throws alot of things in the mix. Anything could have crawled in somewherein that engine. Not sayin thats the problem but there are infinite things that could have went wrong in a year. Really though there has to be if not a timing problem mechanical or electrical and no vacuum leak to be found then it has to be a blockage in the intake assembly. I'm sorry I'm stumped too at this point. How about fuel lines maybe a pinched line/hose, maybe a semi- clogged fuel filter, maybe crap in the bottom of the tank thats being sucked to the fuelpump when the throttle is floored then dropped when let off, maybe a vacuum lock in the tank via fuel cap or clogged vent hose. thats all I can think of right i'm just giving somethings not thought of.

[LokiRx7]

Originally Posted by mr2silvertop

I'm just throwin out any possibilities online diagnosis isn't easy. Sittiing for a year you say? That throws alot of things in the mix. Anything could have crawled in somewherein that engine. Not sayin thats the problem but there are infinite things that could have went wrong in a year. Really though there has to be if not a timing problem mechanical or electrical and no vacuum leak to be found then it has to be a blockage in the intake assembly. I'm sorry I'm stumped too at this point. How about fuel lines maybe a pinched line/hose, maybe a semi- clogged fuel filter, maybe crap in the bottom of the tank thats being sucked to the fuelpump when the throttle is floored then dropped when let off, maybe a vacuum lock in the tank via fuel cap or clogged vent hose. thats all I can think of right i'm just giving somethings not thought of.

I have a TB cap and a block off plate for the exhaust ports on the head. My spare engines sit in wooden jigs that I made to fit the oil pan, they sit in a dry climate controlled garage. The intake couldnt have gotten anything in it, and I had this problem with the prior IM that was off of my recently running car. The filter is new, and I replaced most of the lines, when I got this car it needed a new fuel tank, it had sat for five years.. So it has a new filter, all new lines, even a new filler neck hose, new pump, and unless in six months time I accumulated alot of bad dirty gas I know the tank was spotless when installed.

I havent the slightest idea, unless there is something wrong with the pickup in the distibutor, I am going to change it out for a known good one...

Well first ill break out the BGB and test this distributor and see if its in spec..

[LokiRx7]

Distributor is within spec, replaced it anyway out of frustration, checked ignition coil its also fine. BGB gives no procedure for checking the ignitor, and unfortunately I dont have any spares to check it against...

Unless its the ignitor or the ECU, I havent the slightest idea. And I am getting incredibly frustrated, as the car ran when I dropped the last engine. It just didnt run well because of extremely low compression. The engine that is in the car now ran great when it was removed and stayed in storage until I needed it. I have taken every precaution imaginable to make sure everything was stored properly, and that the swap went smoothly.

All I want to do right now is kick every panel in on the car, obviously Im not actually going to do that, but I want you to have some idea of my frustration...

I have painstakingly checked and double checked everything imaginable and thought of every scenario that I know of that could possibly cause this issue. If anyone has any ideas, or has an ignitor that I could buy, I would appreciate it. I really dont have a clue. And I thank everyone who has suggested anything thus far.

P.S.

Its almost acting like its only firing on two cylinders, I have replaced :

Plugs
Plug Wires/Coil Wire
Distributor Cap
Rotor Button
Entire Distributor
Ignition Coil

All Injectors are operating, and are within spec according to BGB.
Fuel pressure is within spec

Replaced the Intake manifold, and gaskets, checked TPS within spec, replaced TVIS and verified that replacement was functioning. Capped off Brake booster outlet on manifold to ensure it wasnt a cause.

Havent checked the AFM, but any AFM I have experienced going bad, generally wont allow the car to start, perhaps I am wrong. But the injectors functioning leads me to beleive its in the ignition... As soon as I cool off I will check it.

If anyone knows a procedure to check the Ignitor, please let me know.

I highly doubt its the ECU, but so far nothing has alleviated the problems, so I am willing to test any hypothesis.

[LokiRx7]

Checked AFM, perfectly within spec.

I am sure that the ignition timing is properly set, given the fact that I know how the distributor is installed. I think with as many times as I have installed the distributor, the odds are in my favor that I should have accidently gotten it correct by now...

I am at a loss..

EDIT ::

I have trouble codes 2,4,6, and 8. Everything in question is within spec according to the BGB. ECU maybe? I switched my water temp sensor out for a known good one, and I switched my AFM out for a known good one. The same trouble codes returned...

[LokiRx7]

FIXED!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!


Turns out at some point when I disconnected the Distributor, I must have pulled on the connector too hard. The wires on the female end had been almost pulled out the back of the connector, and must have allowed the signal to arch around and blow up my tach. The wires were close too each other when I plugged the male and female ends together, but didnt quite touch. Rigged up a new connection, and BAM! ran GREAT!

Not to worried about it, I have a spare cluster, but now my baby is back on the road!

[mr2silvertop]

congrats!