OK, my problem isn't electrical...

When driving along, the car (1.8 motor, non-turbo) seems to act as if it is stalling out, then starting back up on its own with a wonderful backfire out the exhaust. I've finally had it happen without any electrical load and while only going about 45mph (2200? on tach).

I've replaced plugs/wires/cap/rotor/coil/coil pickup/ignition module; and it still happens. Thought maybe alternator, but I went to autozone and they tested it on the car and told me all electrical systems were fine.

Now I'm looking at fuel delivery, although while grasping at straws here, the fuel filter was just replaced as well.

Should I be looking more at fuel pump or the fuel pressure regulator? I'm really hoping not the regulator as that's a $300 part. Is there a way to test that thing while on the car?

Any other ideas?

I should have recommended this check LONG ago.Simply try disconnecting the EGR valve vacumm line!I do not know if it is located near the distributor as it is on mine.IF the vacumm line removed clears up the issue(guess what )that is the problem.You have two choices either try to clean the unit or replace it.Rough cost 40.00 with out checking.But mine went bad years back,discon it whalaaa.Got mine at napa.What happens is the rubber seals inside the diaphram lose vacumm and choke the shiat out of the engine at various speeds,idle etc.Being any load put on it cold,hot will effect it.I sure hope my vast exper with this resolves it.I want to see all smiles if it does(plus a technical paycheck in the sum of way too much cash to go towards my car)

this could explain why when it happens, i'm always steady on the gas, and when i feel it's about to happen I let off the gas and coast until it calms down and I can continue for a while before it happens again--the vaccum keeps changing when I do that, relieving the pressure. It also idles fine, especailly now that I got the coil pick-up and coil on.

Do I have to plug the end of the vacuum line when I disconnect it from the valve?

NO just simply remove the vacumm line going to the egr valve.It will not hurt the engine or performance.Worst case the vacumm line removed from the egr will only effect the the mpg at best.I sure hope this is the case with ur issue.And if it is cool.(I still want a prepaid visa card) ha ha ha

no gift card for you yet!

I took off the vacuum hose, drove around, still has the problem. With the electrical system checking out fine, I'm guessing it's not the battery cables.

Ok round two.It is time to check the map sensor.It is kind of lengthy to show u how to check it.But in brief disconnect the plug going to it.Mine is on the firewall behind the tbi.Now make two jumper wires.Run one wire from the A on the plug to the sensor.Run one wire from the C on the plug to the sensor.Now using a multimeter place the meters end (RED) in the sensors B plug.The multimer has 4 plug in points.The red goes in the V horseshoe side(the little electri symbols.Place the black lead on the meter beside it (COM) will be on it.Run the other end of the black to a good ground.Place the meter 20v range.IF u have a vacumm gauge hook it up to the vac line to the map itself.Turn ur key ON (ONLY)vac should be at ZERO and the voltage should be 3v-5v.If the vacumm is not at zero or voltage is not in range as above it needs to be replaced.I sure hope u can figure out all this unless I scan this in,and post or check this site. Http://www.wellsve.com click on the tech upper left corner it has a step by step.

I'm gonna check the computer for codes, but shoudln't my check engine light be coming on if this was the MAP sensor?

Is there a way to check the oxygen sensor, think that could be it?

Well sometimes the map maynot set a code.If it is intermented or basicly not a hard code to trigger the ecm to pop the check engine.I suggested this due mine was acting strange but,not enuff to set a code.However once I varified the voltage it was not in range of the voltage.O2 sensor checks would pop a code if it is defective normally but does not always.Checking it requires the multimeter.IF it is very old (I would replace it period) regardless of mileage.I can't remember if u checked ur TPS cable but,if u did not I would as well.Checking it is easy and the site I listed shows how.Car only has to be in the on position (not running) and move the cable and the transition for it moving should be gradual not zippy fast or wayyy to slow.I do not want to flood u with ideas.Start with these.

Sttttteeeeeeeeeeeeeeeeeerike Two!

Would you believe TCC? I know I didn't really think so, but now I'm beginning to like this idea.

OK, took it to a friend and he couldn't get his OBD reader to work with the car. He did test the MAP sensor as you wrote and it was fine. Then I took him for a drive and of course the car wouldn't do it. There was a point where I thought it would happen, and it didn't. That made him tell me that just for kicks, when it happens again, I should try downshifting to 2nd.

So right after I dropped him off, it happened again...was driving about 45mph, steady pedal, boom--backfire. So I drop to 2nd without lifting off the gas and it sounded pretty hellish, but after a second or two I went back to drive.

I got home and started reading the book, and the section around TCC really seems to tell me about what it does and I think this may be the problem--what do you think?

Of course for this, I'll have to take it somewhere to test the TCC, but I'm hoping this will end the drama.

Fine on the 2nd strike(winey pants)HA HA .Any way I had the thought that it might be the TCC switch.I was thinking your car was a MANUAL.However the automatic has issues with the above item.You can test this yourself!! Simply disconnect the switch and drive as usual.This is no will harm the car/trans.If the issue doe go away next is the suggestion.1 drain transmission,and replace the filter and gasket and fluid.2 replace the TCC switch.In short the fluid is probably old which inturn over time loses it ability to reduce heat and wear and it literally gets so hot that it burns up the switch.Normally the issue is when coming to a stop or backing up based on info I have learned.By only changing the fluid/filter will not fix it.By leaving the switch (old part) unplugged only reduces mpg in most cases at best.I know auto zone,advance auto,napa should have this as a in stock item.I know u can look it up,in trans parts and it may not be listed as a torque convertor switch(may be trans solenoid relay,switch or something to that degree.Alright.

This is weird, the more I read about the TCC problem, the less confidence I have in the TCC switch being the problem...according to what I can find, the TCC problem is engine stalling out as someone comes to a stop--I don't have that problem, things get better when I let off the gas, and are just fine when I'm at a stop--my issue is while driving with a steady pedal, the car bucks with a backfire, the feeling is cutting of power and then power comes back immediately (unless it keeps backfiring).

This all sounds to me like it is happening at the point the TCC should ENGAGE.

The shop manual has: the TCC will engage when: vehicle speed above 45mph, engine at normal operating temperature (above 70C, 158F), throttle position sensor output not changing, indicating a steady road speed, transmission third gear switch closed, brake switch closed--THIS is when my problem happens

Mine seems to lose power and backfire, the first time it happened I was doing 60mph on a flat highway. It really seems to hate going up hills lately, and yesterday it even happened when cold and going maybe 35mph.

The car idles great, and always seemed to shift wonderfully until this problem started--do you still think TCC Switch?

If so, how do I disconnect it? I'm not even sure what it looks like and I couldn't find it at autozone.com

http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_Transmission-Control-Solenoid-BWD_18480536-P_838_R%7CGRPSESWAMS_560523687___ This should be the part.It is mounted on the trans top/bottom,side IDK.But this is it.I will ponder things some more.Not to mention I was not sure on the yr,or exact model but,knew the eng.I put 85 type 10 or t type what ever they listed.

1985, 1.8L, O code

Thank you for the link, I would've never found it.

Now I just have to find the darn thing on the car

The more I look into what parts cause what problems, I'm thinking this might be TPS or VSS...

what do you think?

The shop manual tells me where the TPS is, but nothing about symptoms when it is bad, or how to test when the Check Engine Light never comes on. Is there a way to test for a bad TPS?

Easy to check.Using a multimeter place the the black and red connectors to the normal positions(to the right side on most).Now use the pointed needle ends (if u have them) place the black to the ground position on the tps.Place the red to the center pin(should be pwr for it).I forgot disconnect the plug going to the tps to do this duh.U will place the ends on the tps end (fixed) not the plug u disconnect.Now with the car off,key off.Now with the meter set to OHMS 20k move the throttle and the voltage should go and down gradually not bannanas.Moving the throttle from open to wot.Tps sensor can have dead spots,and may or maynot set codes!IF u have any issues understanding the hook up,go to the link Http://www.wellsve.com and go to the section for tests or diagnostics.Alright

Well the TPS was OK, found the TCC and will be trying that out this weekend (hopefully)

Ron, thank you for all the help, I would've been so lost.

No problem.That is what we are all here for.Hopefully the tcc will be the issue.Just disconnecting it and trying things may resolve it.I hope to start working on mine soon just too busy lately with other stuff,plus working on other cars for people on my days off.

Found the TCC, disconnected it and drove a while. Everything went great, the revs are about 500 higher than normal @ 45mph, so I can see where the milage would go down. After driving around, probably about 20 miles with a few stops in there, tried going up some hills since that's where I've had the worst of it. First few hills were great, then it happened again

I tried shifting into 2nd, but it didn't go there. I was now stuck taking roads with a few more hills, got worried, but managed to get the car home (it did allow me to go to 2nd on another hill, and that solved the problem).

So at this point I still believe the transmission area is where I'm looking, and TCC just may be PART of the problem. I'm thinking have the shop do the tranny service, fluid and filter, and since the TCC is under $30, get that replaced as well.

Any thoughts?

One new question to this mess--does the computer control the shifting? I'm thinking it shouldn't on this car, but my friend who checked the MAP & TPS for me suggested that may be the problem.

Well old fluid in the trans in not good.It greatly affects the ability for the car to change gears smoothly and not slip,and lubricate things.I would just do the job urself(seriously).Dropping the pan and replacing the gasket,filter is a pie job.Just make sure if u do not do job,do not install the new TCC switch until after the fact as not to damage it(being the old fluid) may fry it.Umm on the ecm controlling the shifts (to me unlikely) since the car movement and rpms adjust to the cars speed and should not be controlled by it.It may monitor eng items in conjunction with the spd and trans tcc part but,can't say I'm 100% percent on my theory.Since I have a manual it is totally irelevant to the ecm for sure.Get the work done regardless (I am thinking the slow hill climbs) is due to old worn fluid/filter that greatly affects ur cars performance!Btw if u do the work buy some permatex (the right stuff) gasket maker cost for small can 12.50 auto zone the best sealant EVER.

hmm...lying on my back in sub-freezing temps doing a job I'm just not comfortable doing, or have the shop do it for $50...the shop wins!

This is what motorman had to say from sunny Florida (he's there until spring):

I know of the problem that you have,just escapes my recall at the moment for the fix. Had the same problem with my white turbo Buick, but beats the hell outa' me what the cure was. It's been awhile, plus old age.

Needless to say, all of my info is in NJ, so just can't pick something out and shoot it to you. Off the top of my empty head i would suggest the following:

1. Check oil level is full.... watch oil pressure gauge, if you have one, to see if pressure takes a nose dive, just BEFORE the gremlin appears. See at the oil filter there's a pressure switch that cuts off fuel pump if pressure drops to low. This could be caused by a piece of sludge-crap being pushed to sender and blocking oil flow, also pressure sender could be faulty or check that wiring is TIGHT, as engine vibes-movement could cause loss of contact. There could also be a bunch of crap at bottom of oil pan, and when suction becomes great enough, it pulls crap onto screen and blocks oil flow/pressure drops. Not to bad of a job, as I have done all three of mine, so far

well my oil is full, just barely over 3000 since changed so it is due (just been dealing with this problem), so I have my doubts on the oil, but I'll have to check that switch anyway--is there a way to test the switch? I'm gonna do another test drive later today and see if I have the opportunity to eyeball that gauge.

Did another test run today, the oil pressure was fine, and the car behaved better with the TCC disconnected again. Still had the most trouble on that darn hill, but let off gas, shifted to 2nd, all was well.

It did it to me again cold on a flat run at 35mph.

I'm still gonna bet on tranny service and TCC replacement clearing this up. Hope I can get it done this week.

Yeah the info given on the oil pressure sender sounds correct.In short if the oil pressure sender is faulty or let's say blocked up it would inturn cut fuel BC it grounds the system and if it were to malfunction it cuts the fuel period.Hell if ur real bored remove the oil pressure sender(easy) has a rubber boot around it and a two prong terminal across from the oil filter(the other sender beside it) is the idiot light for oil single terminal from the best of my recollection.I have replaced both due to the oil press sender blew oil out like the exxon valdese yrs ago while driving lost two qts.Yeah do the trans service,and the I might suggest if after the service it goes all away leave things as they are.The sending unit is gravy to remove and just put some permatex HI temp thread sealant on the threads(its like liquidy) and white sold at advance or auto zone if u do replace it in the future.The stupid tape to seal threads is such BS.

Well the shop has it now, they say no way to the TCC/tranny being the problem, but the trans service is being done and they are replacing that switch by the oil filter. I expect I'll get the car back tomorrow night, then I get to drive it around and see if this solves it--I really hope so, I don't have any more money to throw at this thing.